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Better Fuel Economy Suggestion for All Cars

Posted By: AEHaas

Better Fuel Economy Suggestion for All Cars - 10/17/19 04:17 PM

Needing a long SUV for my projects and wanting some luxury for “once” I purchased the new Black Label Lincoln Navigator. I got the extended version the first of May this year.

According to their web site:
Capable of producing 450 horsepower* and 510 lb.-ft. of torque,* the twin-turbocharged 3.5L engine in the Navigator** is a true powerhouse. *Horsepower and torque ratings based on premium fuel per SAE J1349® standard. Your results may vary.
**Vehicle shown available at participating Lincoln Black Label Dealers only.

I saw the 0-60 times in as little as 5.5 seconds - attractive for this sports car enthusiast. Note however that these figures assume you are using Premium Fuel. You can use Regular fuel or E85 fuel as well.

The truck is around 6 months old now with around 4,000 miles. Lincoln does free service for the first 4 years, oil changes every 10,000 miles or 1 year intervals. It uses Motorcraft 5-30 fully synthetic oil. It does not get as hot here in Florida as in other places around the country and we do not have any mountains. I never tow anything and never drive over 80 MPH. As such I will be using 5-20 or 0-20 motor oils. As with some others here I could not stand to go 10,000 miles on a single oil change. I chose to put in 5-20 Mortorcraft oil at the 3,000 mile mark. I was hoping to maybe get a little better fuel economy. No change.

It could be that the break-in oil was a 20 grade and that could explain why there was no change. Or there is just not much of a difference as is sometimes the case. If the fuel economy goes down a little after the scheduled change into 5-30 at the dealership in 6 months then we will know the effect of viscosity on my fuel economy. I predict there will be no difference.

I did some experiments with fuel grades in the milage range of 2,500 to 3,000 miles, before the first oil change. Originally I used only premium fuel, mostly Shell. I got 20.5 MPG during this period in my mundane around town driving. I then almost emptied the fuel tank, ran one full tank of Regular gas and then got another tank of Regular and started MPG records again. In fact I have been using only Regular gas since then. Eventually I hit 3,000 miles, changed the oil to a “thinner” one and still had no change in fuel economy. The new readings were 19.5 MPG before and after the oil change.

So I get 5 percent better fuel economy (1 MPG) by using Premium instead of Regular fuel. Even though premium fuels cost more than 5 percent more than regular fuels I will be using it to better the environment by this amount. I have never found that using a 20 grade vs a 30 grade oil made any noticable difference in fuel economy in my cars. But this is a significant difference by using differenct octane fuels.

It occurred to me that we should be using Premium fuel in all cars to get this significant improvement in fuel economy. Maybe we should up the octane of Premium Fuels even higher. Could we get a 5-10 percent better fuel economy rating? Obviously we would have to produce new engines with the necessary timing advancement but we could also retroactively adjust all cars one way or another to take this advantage. Maybe having only one grade of fuel at the station would help reduce its cost making it worth it for the Increased milage.

What say you?

AEHaas
Posted By: supton

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:25 PM

I've read somewhere that many OEM's want to go down that path and make their engines use only premium, presumably for the same reasons you mention (better mpg, more power).

Personally I wouldn't care too much, I mean, if the mpg increase was greater than the increase in fuel cost, then it's a net win for me. It's when it's not that I have second thoughts.

Too bad we couldn't get cars with two fuel tanks, or at least a tank with high octane fuel in it (maybe just a few gallons of something on the other side of 100 octane). That way, for mundane driving, a lower octane fuel could be used, where the extra isn't needed. Under power some of the high octane fuel could be pulled in and mixed in. But I'm guessing what the OEM's are finding is that even at part throttle high octane is required as they are getting some high pressures even at low power output. So that idea probably doesn't work.

Finally... a Prius will handily beat CO2 and other emissions compared to your SUV. That's a rude thing to say I know, and not of any help to someone who has a big family or needs to haul around lots of stuff. I'm no more anti-big-SUV than I am anti-Prius. But if mpg is a concern then quite often a smaller car will obtain a smaller carbon footprint. Not just on fuel but also in tires, used oil and whatnot.

In some ways I wonder if multi-vehicle ownership isn't the way for us to look at in the future. Many of us can afford to have more than one vehicle; maybe one big one and one small one would do us well. That is what I've done, a commuter that I put my miles onto, and a big do-all vehicle that gets few miles due to fuel burn.
Posted By: Blkstanger

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:27 PM

That's not how it works. Just because you got better mileage in your vehicles does not mean others will too. Higher octane fuel is not the solution.
Posted By: Fawteen

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:33 PM

Premium fuel only? As my wife would say, "bless your heart, but no".
Posted By: Kestas

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:47 PM

5%-10% better fuel economy with premium.... which costs 30% more? No thanks.

What is your definition of "fuel economy?"

The name of the game isn't highest mpg, it's lowest fuel cost per mile. Premium doesn't provide that.
Posted By: Rmay635703

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:47 PM

Originally Posted by Blkstanger
That's not how it works. Just because you got better mileage in your vehicles does not mean others will too. Higher octane fuel is not the solution.


This is sort of like saving money on a hybrid or EV,
TCO is terrible because you pay thousands more up front then hundreds extra of taxes every year which wrecks any savings potential

Attached picture 30DFD638-B69E-42EE-B7AB-44F3A52E3E77.jpeg
Posted By: jbutch

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 04:48 PM

The reason you get better mileage with your TGDI with 91 and up octane is because your engine is tuned for this fuel.

It can lower performance/mileage by retarding timing and other thing because it will detect knock from the knock sensor (lower quality fuel) but is not the best for your engine.

Putting 91 octane fuel in a regular NA engines tuned for 87 octane will not see ANY improvement mileage-wise.
Posted By: nthach

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:13 PM

Originally Posted by jbutch


Putting 91 octane fuel in a regular NA engines tuned for 87 octane will not see ANY improvement mileage-wise.

Toyota words the owner's manual of their V6 models that while 87 octane is fine for everyday use, premium is suggested to realize the best performance out of the engine. Premium isn't recommended for a Prius - it burns slower which may encourage combustion chamber and valve deposits which might result in delayed start/no crank DTCs.

I caught the parents trying to cheap out on fuel with their LS430 by using regular and adding in a bottle of Techron but I told them it's not the additives, it's the octane and you will be burning more gas than you "saved" and maybe causing long-term issues. I warned them if you want to cheap out, I'd rather you use Arco or no-name premium.
Posted By: Wolf359

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:14 PM

Originally Posted by Rmay635703
Originally Posted by Blkstanger
That's not how it works. Just because you got better mileage in your vehicles does not mean others will too. Higher octane fuel is not the solution.


This is sort of like saving money on a hybrid or EV,
TCO is terrible because you pay thousands more up front then hundreds extra of taxes every year which wrecks any savings potential


Wow, that's a really big spread between regular and premium. The mid grade is a real money maker though, should be half of regular and half of premium so it should be $3.25 instead of $3.70. So they make an extra 45 cents per gallon.

As for the OP, 3k oil changes are somewhat extreme. I used to do 5k oil changes on semi synthetic and got over 200k on a Ford Taurus. Would go up to 7 or 8k once in a while when I didn't have time to change it. Doing 3k oil changes is just a waste of oil and bad for the environment, a large percentage of oil doesn't get recycled. I do 10k oil changes now on my Mercedes which is what it calls for. It has an 8.5 quart sump so I figure it doesn't get used up as much as a car that only does 4 or 5.
Posted By: Jimmy_Russells

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:18 PM

OEM's have actually been pushing for 91 to become regular fuel for quite some time. They believe they can really increase both mileage and power if that was the case. I'm all for it if they can leave the "regular" prices as they are now and just eliminate 87 and 89 altogether. Maybe have 91 as regular and 93 or 94 as premium.
Posted By: Brons2

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:28 PM

I would be curious to see the results of ethanol free 87 vs. regular E10 87. They have no-ethanol 87 at Walmarts around here. It costs more than premium, but, could be an interesting experiment.

As it is, I use the ethanol free fuel in all my OPE. Starts right up after sitting for a couple of months.
Posted By: SubieRubyRoo

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:31 PM

Originally Posted by Jimmy_Russells
OEM's have actually been pushing for 91 to become regular fuel for quite some time. They believe they can really increase both mileage and power if that was the case. I'm all for it if they can leave the "regular" prices as they are now and just eliminate 87 and 89 altogether. Maybe have 91 as regular and 93 or 94 as premium.


If the cheaters hadn't ruined diesel for everyone, we'd be going down a much better path for MPGs. Not only does diesel contain a significantly higher energy per volume than gasoline, but you can also "refine" approximately 25% of crude oil into usable diesel just by heating it up to about 900*F and removing the lighter fractions. There's other stuff that goes on I'm sure (I'm not a refinery chemist, but I did stay at a Holiday Inn Express last month) but that's how it was told to me when I was working at Citgo & BP refineries in IL. Plus, with compression ignition, there is no LSPI, no detonation, unlimited boost potential within the limits of the block/head architecture, and others. But you'll also need biocides, anti-gel chemistry, and water removal as well.

I think the biggest pitch "for" diesels is this: Americans are drawn to buy a vehicle with high horsepower ratings, but unconciously enjoy driving high torque engines. They just feel more responsive and snappy, and are much more usable than something with [email protected]
Posted By: Jimmy_Russells

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:34 PM

It's all about compression, which is why they want higher octane as standard. More compression is virtually always better in terms of power and economy and therefore more efficiency.
Posted By: ecotourist

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:38 PM

Hello Dr Haas,

You'd have to do quite a few test tanks to be sure that there really is an increase in mileage.

If you're getting better mileage it could be because your vehicle is set up for it, though most vehicles are not.

In Canada premium (RON 91) gasoline is generally ethanol free, whereas regular (RON 87) gasoline has up to 10% ethanol. You will get better mileage without ethanol and the absence of ethanol alone would explain better mileage.

According to an article I read some years ago, ethanol made from corn isn't really better for the environment as there is so much fuel used in producing it. We have corn based ethanol added to gasoline in Canada too but it seems it's mostly a feel good issue. And the farm lobby likes it too.

Finally, it used to be said that premium fuel required 10% more crude oil base-stock to produce. But that was a long time ago and I don't know the current situation. It seems likely that it requires more at least.

All in all, I'm not convinced about premium fuel being "better for the environment".
Posted By: EricG

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 05:57 PM

So I get 5 percent better fuel economy (1 MPG) by using Premium instead of Regular fuel. Even though premium fuels cost more than 5 percent more than regular fuels I will be using it to better the environment by this amount.

So your trying to better the environment by driving a Navigator and doing 3K mile oil changes??? Dude, if you can afford a Navigator, put 93 octane gas in it and run the recommended 5W30 oil down to 20% or so on the OLM and you and the ecoboost live happily ever after.
Posted By: Davejam

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 06:24 PM

There isn't enough capacity to produce high octane fuel, so no.
Posted By: Kestas

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 06:50 PM

Originally Posted by Jimmy_Russells
OEM's have actually been pushing for 91 to become regular fuel for quite some time. They believe they can really increase both mileage and power if that was the case. I'm all for it if they can leave the "regular" prices as they are now and just eliminate 87 and 89 altogether. Maybe have 91 as regular and 93 or 94 as premium.

OEMs have been pushing this in order to help meet CAFE standards while maintaining horsepower. All this at the expense of your pocketbook because premium costs 30% more than regular. America has lost focus with the almighty one-track CAFE standard, when we should be aiming for the least cost per mile traveled.
Posted By: PimTac

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 07:03 PM

My experience has shown better fuel economy with running 91-92 octane premium. The difference is about 1.5 to 2 mpg. This is on a Mazda SkyActiv 2.5 naturally aspirated engine which has 13:1 compression.

In addition, response and power, especially going up hills is better with the premium. It might cost me more but with everything I’ve observed I will stay the course.
Posted By: bulwnkl

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 07:29 PM

Originally Posted by Kestas

OEMs have been pushing this in order to help meet CAFE standards while maintaining horsepower. All this at the expense of your pocketbook because premium costs 30% more than regular. America has lost focus with the almighty one-track CAFE standard, when we should be aiming for the least cost per mile traveled.


Not necessarily. If you actually increase compression ratios and thus improve energy extraction (thermal efficiency), the trade needn’t be nearly so bad as you imply. Your rationale argues for bringing the high-altitude 85 AKI regular (or lower) to the rest of the continent simply because it’s cheaper to buy at the pump.
Posted By: OVERKILL

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 07:30 PM

Originally Posted by PimTac
My experience has shown better fuel economy with running 91-92 octane premium. The difference is about 1.5 to 2 mpg. This is on a Mazda SkyActiv 2.5 naturally aspirated engine which has 13:1 compression.

In addition, response and power, especially going up hills is better with the premium. It might cost me more but with everything I’ve observed I will stay the course.


Yes, typically engines with higher compression will benefit. Our 5.7L "requires" 87 at minimum, but recommends 89. Since Costco only carries 87 and 91, it gets 91. The CR on it is 10.5:1.
Posted By: CharlieBauer

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 07:42 PM

Originally Posted by Wolf359
Wow, that's a really big spread between regular and premium. The mid grade is a real money maker though, should be half of regular and half of premium so it should be $3.25 instead of $3.70. So they make an extra 45 cents per gallon.


The 91 does not say "Contains 10% Ethanol" either.

Costcos in CA have a 20c to 30c spread between 87 & 91 so about 5%.
Posted By: Lou_Boyle

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 08:14 PM

In my experience, using the car computer to monitor avg fuel economy while driving the same section of interstate on cruise control on multiple trips, the biggest variable in the "observed" fuel economy is simply wind direction. My mileage using the same car, same tank of gas, same tire inflation, will vary 10% from minimum to maximum depending on which way the wind is blowing. In extreme conditions, like a stiff headwind from a cold front coming through, I have seen the spread widen to as much as 15%.
Posted By: Mad_Hatter

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 08:26 PM

First off..congrats on the Navigator OP, nice ride 👍

Not sure I would consider a 1mpg difference statistically significant, certainly not worth the added cost of premium IMO. Unless you have a dirty combustion chamber or it's called for in the owners manual, you're [censored] your money away using a higher octane fuel.

But..it's your wallet, your car...do as one does.😉

*and you're not likely to see any meaningful difference in mpgs from using a 0w20 v. a 5w20 v. a 5w30. At operating temp there's just not that much difference in viscosity (drag) to make a difference IRL applications. Maybe in a lab on a Dyno but certainly not out on the streets.
Posted By: paoester

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 08:28 PM

Originally Posted by AEHaas
I chose to put in 5-20 Mortorcraft oil at the 3,000 mile mark. I was hoping to maybe get a little better fuel economy. No change.
20 weights won't always get better fuel economy in an engine speced for a 30 weight. (The 4:00 minute point of Angela's presentation at https://www.youtube.com/watch?v=0B6SHa4qv60 )
I would suggest using a thin-side 5w30 with great specs, as in Pennzoil Platinum 5w30 which should give you optimal results (kv100 9.8, add some fuel dilution, only a little, and it's a heavy-side 5w20).



Originally Posted by CharlieBauer
Originally Posted by Wolf359
Wow, that's a really big spread between regular and premium. The mid grade is a real money maker though, should be half of regular and half of premium so it should be $3.25 instead of $3.70. So they make an extra 45 cents per gallon.
The 91 does not say "Contains 10% Ethanol" either. Costcos in CA have a 20c to 30c spread between 87 & 91 so about 5%.
Yet ethanol or methanol can increase octane rating. You did NOT want to be chased by an ME 109 with methanol-water injection activated, as one example from 1944.

You only need it injected at the right times:

"Cohn and Bromberg dealt with that problem using alcohol. When the SI engine is working hard and knock would otherwise occur, a small amount of ethanol or methanol is injected into the hot combustion chamber, where it quickly vaporizes, cooling the fuel and air and making spontaneous combustion much less likely. In addition, because of alcohol’s chemical composition, its inherent knock resistance is higher than that of gasoline. The alcohol can be stored in a small, separate fuel tank — as exhaust-cleanup fluid is stored in a diesel engine vehicle. Alternatively, it could be provided by onboard separation of alcohol from gasoline in the regular fuel tank. (Almost all gasoline sold in the United States is now a mix of 90 percent gasoline and 10 percent ethanol.)" --
http://news.mit.edu/2018/mit-researchers-gas-alcohol-engine-getting-world-off-dirty-diesels-0613
Posted By: tcp71

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 08:41 PM

Why you would go to a lighter than spec’d oil on a direct injection twin turbo vehicle making 125 hp/litre and even more than that in torque makes me shake my head. Ford tried 5w20 when the first generation of that engine came out and ditched it for 5w30. You buy a navigator then scrimp on fuel by trying thinner oil?

It’ll run fine on regular fuel, and the way you describe your driving, you’ll never need the extra few ponies premium brings. Save your bucks there.
Posted By: Dave1027

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 09:38 PM

I also notice slightly better MPG with higher octane fuels. But more importantly, I find my vehicles run like crap on cheap octane 87. They stumble and bog. No issues with 89 or 91.
Posted By: rooflessVW

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 09:41 PM

I filled up the Touareg with diesel and got 29.2mpg!

Running premium in the Atlas does not affect the fuel economy at all - but it does smooth out the engine.
Posted By: OilReport99

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 09:51 PM

Best fuel economy vehicle you can buy! Run it with gas - any gas - diesel, or just used motor oil from your fellow BITOG'ers!

Save the planet's resources and save some money while you're at it!

[Linked Image from i.ytimg.com]
Posted By: Rmay635703

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 10:00 PM

Govliquidation is selling a bunch of MTVRs and humvees
Posted By: A_Harman

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 10:04 PM

Originally Posted by Jimmy_Russells
OEM's have actually been pushing for 91 to become regular fuel for quite some time. They believe they can really increase both mileage and power if that was the case. I'm all for it if they can leave the "regular" prices as they are now and just eliminate 87 and 89 altogether. Maybe have 91 as regular and 93 or 94 as premium.


I remember GM made a proposal on that a while back. It all sounded good until I read to the lower part of the story, where they said the octane increase would come from a higher percentage of ethanol. NO SALE, said I, unless the high-ethanol 91 could be made to cost the same as 89, and give me the same driving range on a tank of fuel. This I doubt could be done.
Posted By: ka9mnx

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 10:07 PM

I tried higher octane in my 4Runner but not the spread you did. My OM says 87 or higher so I tried 89. I ran several tank fulls so the computer could adjust (timing, etc). No change in MPG. Guess I don't have enough compression in the old girl to take advantage of the slower burning fuel.
Posted By: A_Harman

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 10:07 PM

Originally Posted by OVERKILL
Originally Posted by PimTac
My experience has shown better fuel economy with running 91-92 octane premium. The difference is about 1.5 to 2 mpg. This is on a Mazda SkyActiv 2.5 naturally aspirated engine which has 13:1 compression.

In addition, response and power, especially going up hills is better with the premium. It might cost me more but with everything I’ve observed I will stay the course.


Yes, typically engines with higher compression will benefit. Our 5.7L "requires" 87 at minimum, but recommends 89. Since Costco only carries 87 and 91, it gets 91. The CR on it is 10.5:1.


Have you tried a 50/50 blend of the 87 and 91 at the pump to get a lower-cost 89? I do that sometimes on my Camaro when I pull into a station that has 87 and 93. Sometimes I can actually get 87/93 blend, which may or may not be 90 at lower cost than I can get 89 from the pump.
Posted By: ZeeOSix

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 10:12 PM

Originally Posted by Rmay635703
This is sort of like saving money on a hybrid or EV,
TCO is terrible because you pay thousands more up front then hundreds extra of taxes every year which wrecks any savings potential

[Linked Image]


That a crazy huge price difference between octanes. Most I've ever seen here is maybe 20-25 cents difference between octanes. Who would use 87 mid grade or 91 high octane when the 89 is well over a dollar per gallon cheaper.
Posted By: Rav4H2019

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 11:41 PM

Navigator and trying to save the environment smile


Please check out a hybrid Toyota.
Posted By: PimTac

Re: Better Fuel Economy Suggestion for All Cars - 10/17/19 11:51 PM

Originally Posted by A_Harman
Originally Posted by OVERKILL
Originally Posted by PimTac
My experience has shown better fuel economy with running 91-92 octane premium. The difference is about 1.5 to 2 mpg. This is on a Mazda SkyActiv 2.5 naturally aspirated engine which has 13:1 compression.

In addition, response and power, especially going up hills is better with the premium. It might cost me more but with everything I’ve observed I will stay the course.


Yes, typically engines with higher compression will benefit. Our 5.7L "requires" 87 at minimum, but recommends 89. Since Costco only carries 87 and 91, it gets 91. The CR on it is 10.5:1.


Have you tried a 50/50 blend of the 87 and 91 at the pump to get a lower-cost 89? I do that sometimes on my Camaro when I pull into a station that has 87 and 93. Sometimes I can actually get 87/93 blend, which may or may not be 90 at lower cost than I can get 89 from the pump.




I haven’t considered that. Fortunately the price spread here seems to better better than what others are posting.
Posted By: tiger862

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 01:21 AM

On my Caravan it is a flex fuel vehicle so I tried 89 octane and took awhile to adjust before it got smooth but still not perfect and maybe 1 mpg change not enough for me to use regularly. On regular it is smooth through out RPM range and all sites and manual states tuned for regular. Timing only changes with ethanol level so I run regular.
Posted By: Mitch Alsup

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 01:26 AM

I have a slightly different take on this:: perspective: I own and drive a 2017 GLS 450 and I use primarily mid-grade gasoline. Mercedes wants me to use premium gasoline.

On several long (2000+ mile) road trips, I have achieved almost 30 MPG over an entire day::

[Linked Image]

This being almost 8 MPG better than EPA simply shows how much knowing how to drive influences how many miles per gallon one gets.

Attached picture GLS45003.JPG
Posted By: Eddie

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 01:41 AM

I think the "one octane" fuel for all new vehicles would be 93 or 94. That would basic eliminate the 87 and 89 for all except maybe for stationary use. That would simplify things for the gasoline producers ane we would have higher standard compression daily. drivers give better fuel economy. There wouldn't be the 30% increase that we pay now for premium over 87 octane that some naysayers suggest. I believe it could be a win-win for all. Ed
Posted By: ls973800

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 01:44 AM

Originally Posted by tcp71
Why you would go to a lighter than spec’d oil on a direct injection twin turbo vehicle making 125 hp/litre and even more than that in torque makes me shake my head. Ford tried 5w20 when the first generation of that engine came out and ditched it for 5w30. You buy a navigator then scrimp on fuel by trying thinner oil?

It’ll run fine on regular fuel, and the way you describe your driving, you’ll never need the extra few ponies premium brings. Save your bucks there.


I have read the same thing, the EcoBoost engines should run the 5W30 oil. I don't know what repercussions you would have running a 0W20 or 5W20 while under factory warranty if engine work was required.

Stick with the factory recommendation regarding the oil until the warranty is up in my opinion.
Posted By: OVERKILL

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 01:59 AM

Originally Posted by A_Harman
Originally Posted by OVERKILL
Originally Posted by PimTac
My experience has shown better fuel economy with running 91-92 octane premium. The difference is about 1.5 to 2 mpg. This is on a Mazda SkyActiv 2.5 naturally aspirated engine which has 13:1 compression.

In addition, response and power, especially going up hills is better with the premium. It might cost me more but with everything I’ve observed I will stay the course.


Yes, typically engines with higher compression will benefit. Our 5.7L "requires" 87 at minimum, but recommends 89. Since Costco only carries 87 and 91, it gets 91. The CR on it is 10.5:1.


Have you tried a 50/50 blend of the 87 and 91 at the pump to get a lower-cost 89? I do that sometimes on my Camaro when I pull into a station that has 87 and 93. Sometimes I can actually get 87/93 blend, which may or may not be 90 at lower cost than I can get 89 from the pump.


No, but given how cheap 91 is at Costco (cheaper than 89 at most gas stations) I'm not too concerned about it. It's not worth the hassle to try and mix it myself at the pump, particularly given how busy Costco is.
Posted By: JohnnyJohnson

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 02:10 AM

Most of the newer non turbo cars are so detuned they can't take full advantage of premium gasoline. But then I remember the time when nothing under 95 Octane was premium and 92 was what they call sub octane gas sold by the discounters like Gull.
Posted By: PimTac

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 02:19 AM

Originally Posted by JohnnyJohnson
Most of the newer non turbo cars are so detuned they can't take full advantage of premium gasoline. But then I remember the time when nothing under 95 Octane was premium and 92 was what they call sub octane gas sold by the discounters like Gull.




You are dating yourself there Johnny. 😉

In Tacoma we had a Hancock station that I used in the 70’s. It had those dial-a-matic octane pumps. Even then that part didn’t work but you could tell the attendant to fill Er up with ethyl.
Posted By: Cujet

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 02:34 AM

Originally Posted by AEHaas
I purchased the new Black Label Lincoln Navigator. the twin-turbocharged 3.5L engine

What say you?



Nice vehicle!

FWIW, I feel I should mention that Ecoboost engines are exceptionally reliable engines when they are well maintained. Thin oils, fuel dilution and infrequent oil changes are known 3.5L timing chain killers. Instead, I'd choose a synthetic 10W-30 (for less shear) and change at 5000 mile intervals. As you don't need the low temperature pumpability here in FL.

Doing so will prevent a $4000 timing chain replacement at 80K miles.


Posted By: 4WD

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 03:21 AM

Nice spaceship you bought there !
When we bought our 2015 ecoboost - the dealer said they run a bit better on premium but the engine can adjust to various fuels.
We ran mid grade but I never check MPG - was always thinking about how power intense the motor is and the chance of LSPI. Ran 5w30 M1 EP for 5K OCI.
Those things have lots of timing chain - so I kept the oil clean.
Posted By: JohnnyJohnson

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 03:37 AM

Originally Posted by PimTac
Originally Posted by JohnnyJohnson
Most of the newer non turbo cars are so detuned they can't take full advantage of premium gasoline. But then I remember the time when nothing under 95 Octane was premium and 92 was what they call sub octane gas sold by the discounters like Gull.

You are dating yourself there Johnny. 😉

In Tacoma we had a Hancock station that I used in the 70’s. It had those dial-a-matic octane pumps. Even then that part didn’t work but you could tell the attendant to fill Er up with ethyl.

Yes I remember Hancock stations. Yes and I can remember 17.9 a gallon regular and that wasn't a gas war it was every day price.
Posted By: PimTac

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 03:48 AM

I remember prices down that low too. Life was good until the Saudi boycott.

There were lots of gas stations then that are not around anymore. Douglas was another one. Mobil, Phillips 66, and a few more.
Posted By: Kestas

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 11:32 AM

Originally Posted by Eddie
I think the "one octane" fuel for all new vehicles would be 93 or 94......... There wouldn't be the 30% increase that we pay now for premium over 87 octane that some naysayers suggest. I believe it could be a win-win for all. Ed

The problem with me is I don't believe this. Why isn't premium cheaper now, when 40% of new cars recommend it?
Posted By: JohnnyJohnson

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 12:01 PM

Originally Posted by Kestas
The problem with me is I don't believe this. Why isn't premium cheaper now, when 40% of new cars recommend it?

One reason is you seldom see prices go down. Two you have never had higher taxes on gasoline than you do now. Its something like 70 cents a gallon here in Washington between the Federal and State taxes.
Posted By: MNgopher

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 12:52 PM

A high horsepower direct injection turbocharged engine with a history of some fuel dilution in its past and the decision is to not follow the manufacturer recommendation on oil viscosity... and to go thinner to boot. As noted, this engine series did start with an xw20 recommendation. Yet ford reversed that. Interesting thought process...

As far as the premium fuel discussion goes, the only reason the EcoBoost engines can take advantage of higher octane fuels is specifically because they were tuned that way,and as result can use less boost with the higher octane. Even scientific testing picks up on that. (See the NHTSA report on the 3.5l EcoBoost as an example).

What that does not do is improve cost per mile metrics. The cost for premium fuels is greater than the fuel mileage gains achieved.

And while it's easy to say just make it all premium, it won't cost more, it isn't that easy. Refiners have only so much capacity to refine high octane fuel. There are limitations based on feedstocks, refinery equipment, and blending capabilities. The data I could find on short notice indicates less than 10% of fuel sold today is premium. Does anyone think that making the other 90% premium is as simple as the refiners just flipping a switch? It isn't- and the end user would need to pay that cost.
Posted By: MNgopher

Re: Better Fuel Economy Suggestion for All Cars - 10/18/19 12:54 PM

Saying taxes is the cause of the price spread seen between premium and regular is laughable. Same gas tax on either grade (unless there is a sales tax percentage also applied).
Posted By: Saabist

Re: Better Fuel Economy Suggestion for All Cars - 10/19/19 12:21 AM

Carbon footprint is not a concern since CO2 is not a pollutant. I don't take it into account in any of my purchasing decisions. When it comes to real pollutants that produce smog, modern gasoline vehicles have been incredibly clean emissions-wise since the advent of fuel injection, 3-way catalytic converters, and computerized engine management systems - all things that have been around for over 20 years. So unless you're looking at something really ancient if everything is working properly it's going to be a clean machine.

I know that my old Saab will adjust to whatever fuel is put in it. Best performance and mileage is with Premium. You can run it on Regular with no issues other than lower performance and a bit more fuel consumption. (I have not checked to see if the difference in mileage pays for the higher cost of Premium gas - the car runs best on it so that's what I use. It's a small part of overall ownership costs.)
Posted By: Kestas

Re: Better Fuel Economy Suggestion for All Cars - 10/19/19 03:44 PM

Originally Posted by JohnnyJohnson
Originally Posted by Kestas
The problem with me is I don't believe this. Why isn't premium cheaper now, when 40% of new cars recommend it?

One reason is you seldom see prices go down. Two you have never had higher taxes on gasoline than you do now. Its something like 70 cents a gallon here in Washington between the Federal and State taxes.

Complete nonsense. One, prices go up and down. Two, taxes on gas are irrespective of grade.

One thing that is constant is the price disparity between regular and premium has increased over the years on a percentage basis, regardless of the actual price. Premium used to be 10% to 15% more than regular. Now premium is 25% more.

Again, my concern is the fuel cost going from point A to point B, not mpg. If 85 octane gives the cheapest per mile cost, then bring it on.

I know that most people on this site are enthusiasts, but not all of the driving public is into owning and feeding high compression machinery.
Posted By: Mad_Hatter

Re: Better Fuel Economy Suggestion for All Cars - 10/19/19 04:10 PM

Originally Posted by Saabist
Carbon footprint is not a concern since CO2 is not a pollutant.

Not according to the EPA and the US Supreme Court, which ruled in favour of the EPA during the Bush administration in 2007 that CO2 met the scientific definition of a "pollutant" and can be regulated.
Posted By: OVERKILL

Re: Better Fuel Economy Suggestion for All Cars - 10/19/19 04:22 PM

Originally Posted by Kestas
One thing that is constant is the price disparity between regular and premium has increased over the years


Yes, I can attest to the accuracy of this. In Canada, the difference, in more recent memory (I'm sure it was even closer back in the 80's) was that there was a 5-cent spread between the grades. So if you went to the pump you'd see something similar to this:

- Regular (87) - $0.799
- Plus (89) - $0.849
- Premium (91) - $0.899

If it was a Sunoco, there'd also be "Ultra 94" at $0.949 or so.

Now, there's no rhyme or reason to the spread crzy

At McEwan for example:
- Regular (87) - $1.096
- Plus (89) - $1.216
- Premium (91) - $1.276

Or, at Petro-Canada:
- Regular (87) - $1.106
- Plus (89) - $1.259
- Premium (91) - $1.393
Posted By: CT8

Re: Better Fuel Economy Suggestion for All Cars - 10/20/19 08:21 PM

Dr Haas you mentioned performance .
Posted By: bbhero

Re: Better Fuel Economy Suggestion for All Cars - 10/20/19 11:08 PM

Yep...

Amazing how it is not regulated by the world champion flying around in his private jet talking about all this stuff... Which use more fuel in one cross country trip back and forth than the average American uses in a calendar year... And has a 10,000 sq ft home... That he obviously does not need that big... . And has two homes... Plus this individual has profited greatly... Selling this belief... Now that he and his buddies say methane is terrible too... This individual has a lot of money tied up to a company called Better than Meat...So... This individual can make more money on both sides of this supposedly "huge" problem... Follow the money is what they say... And it is true here too. Also... See if the individual actually lives out what they supposedly believe... If there is a huge difference between the two...
Posted By: Amkeer

Re: Better Fuel Economy Suggestion for All Cars - 10/21/19 11:05 AM

Originally Posted by Saabist
Carbon footprint is not a concern since CO2 is not a pollutant. I don't take it into account in any of my purchasing decisions. When it comes to real pollutants that produce smog, modern gasoline vehicles have been incredibly clean emissions-wise...

https://en.wikipedia.org/wiki/Carbon_dioxide

Need to read a little more about CO2.
Posted By: BMWTurboDzl

Re: Better Fuel Economy Suggestion for All Cars - 10/21/19 12:09 PM

Originally Posted by Mad_Hatter
Originally Posted by Saabist
Carbon footprint is not a concern since CO2 is not a pollutant.

Not according to the EPA and the US Supreme Court, which ruled in favour of the EPA during the Bush administration in 2007 that CO2 met the scientific definition of a "pollutant" and can be regulated.


Massachusetts v. Environmental Protection Agency (2007)

It was the State of Massachusetts which argued that CO2 was a pollutant. The EPA (Under the Bush Administration.) argued it was not and lost in a 5-4 decision. It wasn't until the next Administration that the EPA began to regulate CO2. IJS
Posted By: ad_infinitum

Re: Better Fuel Economy Suggestion for All Cars - 10/24/19 05:18 AM

Originally Posted by BMWTurboDzl
Originally Posted by Mad_Hatter
Originally Posted by Saabist
Carbon footprint is not a concern since CO2 is not a pollutant.

Not according to the EPA and the US Supreme Court, which ruled in favour of the EPA during the Bush administration in 2007 that CO2 met the scientific definition of a "pollutant" and can be regulated.


Massachusetts v. Environmental Protection Agency (2007)

It was the State of Massachusetts which argued that CO2 was a pollutant. The EPA (Under the Bush Administration.) argued it was not and lost in a 5-4 decision. It wasn't until the next Administration that the EPA began to regulate CO2. IJS


Just to clarify the legal point made here, as that is what I am interested in, not whether CO2 is a pollutant- only the EPA specified that CO2 is a pollutant, not the Supreme Court. The Supreme Court can not make a finding of fact on such issues. The Supreme Court in this capacity is not a fact-finding court, it only has appellate jurisdiction - meaning they review the law, not the facts.

In Mass. v. EPA, the Supreme Court was reviewing the EPA authority to not make a regulation under the Clean Air Act for CO2. The Bush EPA said that they did not have authority under the statute to regulate CO2, and therefore they did not regulate. However, it was shown, through evidence introduced in the district court (which is the fact finder) that CO2 was an air pollutant. Therefore, because CO2 was a pollutant, and the EPA chose to not regulate it - without explanation - which was a violation on the Clean Air Act, the Court held that when the “EPA rejected the rulemaking petition based on impermissible considerations. Its action was therefore “arbitrary, capricious, or otherwise not in accordance with law,” §7607(d)(9). On remand, EPA must ground its reasons for action or inaction in the statute.”

Posted By: TiredTrucker

Re: Better Fuel Economy Suggestion for All Cars - 10/25/19 02:17 PM

In keeping with the title of this thread, the best suggestion is having the driver figure out how to properly drive the vehicle. In many fleet studies over the years, it is found that the driver accounts for 33% of any positive or negative affect on fuel economy. Yet, car owners are always looking for some sort of "magic pill" to give them better fuel economy when it resides within themselves.
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