Project Farm testing impacts of octane and ethanol content on power and mpgs...interesting!

[SubieRubyRoo]

Unrelated but I like it so I'm posting it b/c I think Judge Smails would like PF testing.

"It's easy to grin, when your ship comes in, and you've got the stock market beat. But the man worthwhile, is the man who can smile, when his shorts are too tight in the seat." - Judge Smails

Sounds like Dr Seuss

 

[twX]

There is no reason highway cruising should net any more mpg on a higher octane fuel vs. low. You will make a little more power for sure. I collected data for 2 years on my Sportwagen and some of that was before being tuned and running 87 and 93, zero difference hand calculated mpgs. Same for our Atlas with many swearing up/down that running 93 nets more mpgs...never have seen it.

That's the case with many engines, especially older ones, but many modern high-compression direct-injection engines are knock-limited at fairly low engine loads. My DIT Subaru becomes knock-limited at 15-20% throttle, and loads will usually be at least this high in highway cruising on a flat road. Advancing the ignition timing at any loads greater than this does improve power and fuel economy, though not as much as it does at higher engine loads.

 

[TiGeo]

That's the case with many engines, especially older ones, but many modern high-compression direct-injection engines are knock-limited at fairly low engine loads. My DIT Subaru becomes knock-limited at 15-20% throttle, and loads will usually be at least this high in highway cruising on a flat road. Advancing the ignition timing at any loads greater than this does improve power and fuel economy, though not as much as it does at higher engine loads.

Both my Sportwagen and Atlas are 2018s....DI with the GSW being turbo. See my graphs above. Even the NA VR6 in my Atlas is knock-limited and while based on that graph I'm making less power at WOT, I never have seen any mpg differences switching between 87 and 93 that were not attributed to normal variation of the many variables invovled in measuring mpgs.

 

[SubieRubyRoo]

Both my Sportwagen and Atlas are 2018s....DI with the GSW being turbo. See my graphs above. Even the NA VR6 in my Atlas is knock-limited and while based on that graph I'm making less power at WOT, I never have seen any mpg differences switching between 87 and 93 that were not attributed to normal variation of the many variables invovled in measuring mpgs.

Yes, but since you understand scientific testing, confirmation bias is not one of the variables that can affect mpgs, let alone by a factor of 10%+. Some folx aren’t as lucky…

 

[sk_pete]

carb, air engine.... temps are all over the place.
so etanol may help cooling...

 

[Torrid]

Which year GTI?

2018.

 

[FishFry]

At least on my 2018 I show a very noticeable 2-3 mpg better on premium than regular and another 1-2 on premium no ethanol with lots of highway driving.

On German Autobahn when you floor it maybe ;-)

But at normal cruising speeds, you barely filling the cylinders, making maybe 35 HP at 1500 rpm as you go.
No way that octane is making a difference there, unless your advance curves are all over the place.

 

[nicholas]

In hot weather my 16 mazda 6 would run poorly with 87.
Jump to 91 and all was well in the hot summer.

It was definitely pulling timing on the 87 in the summer heat. Especially after a highway drive with the AC on.

 

[bonjo]

I switched from regular 95RON to super unleaded (97~99RON) about 2 years ago when regular ethanol content went from 5 to 10%.

This is in both my bikes and my car (which is not tuned). I deffinitely see a change in performance & fuel consumption (more pronounced with the car).

Our super unleaded is up to 5% ethanol and claim to contain more beneficial additives. So in my case any of these could be the reason the improvement in performance: ethanol content, higher octane, additives.

One thing that is also differenct, during the cold season Dec~Mar, my mpg drops more that it should and switching back to regular E10 solves this. I wonder if they don't change the super uleaded fomulation for winter use

 

[MrGraybeard]

I know these threads will never go away on any forum. But what you say is very simple, factual, and to the point.

Not sure why but I guess it's very human nature to take some rating and apply it to goodness. 25 years ago it was referred to as the megapixel conundrum.

I like to ask why is it I can buy 93 octane, yet in Calif. there usually is only 91. What happened to the goodness of the 93-91=2?

In my area, Western Great Lakes, 93 octane gas is an ethanol blend. Non-ethanol is 91.

 

[Pablo]

I just thought of something. Our 2018 1.5T CRV doesn't fuel dilute, at least I never caught it in the act. Around 80K miles IIRC.

We only run top tier premium. Exclusively.

 

[grammatoncleric]

It will be interesting to see how this thread goes. BITOG folks love to hate on PF. I mean, I kinda get why, but, when taken in the correct context, I find most of his videos interesting. The guy puts a lot of time, effort, and creativity into what he does. Are they the absolute end all, be all definitive authority on everything? Of course not, but I don't think that he claims them to be either.

BITOG are just jelly that they don't have the same time and resources on their hands to perform the same tests. As always it's easier to critique than do.

 

[grammatoncleric]

.....
ALSO BITOG: posts with pictures of dipsticks wiped on paper towels to determine "things"

If my memory serves me correctly, the same method was used during the WW2 Pacific campaign in order to diagnose VD.

 

[kschachn]

BITOG are just jelly that they don't have the same time and resources on their hands to perform the same tests. As always it's easier to critique than do.

I’m not performing stupid “tests” on motor oils to achieve zero relevant results. For what reason? What material property is being measured that has no existing test?

Considering the gravity of many of your previous posts here I’m inclined to think you really don’t know the answer to that.

 

[RDY4WAR]

If my memory serves me correctly, the same method was used during the WW2 Pacific campaign in order to diagnose VD.

Because it was 80 years ago and they had nothing better to check with on Midway or Guam in the pacific ocean.

 

[SugarMouth]

Here is my Atlas with a 3.6L VR6 which used to call for premium/91+ in cars years ago now running off 87. Ignition correction/"knock retard" 87 vs. 93 shown on my graphs - logged using a VW scan tool on the same stretch of road/temps/conditions are "close enough" for BITOG. 93 for sure is reducing the timing corrections under WOT which will translate to more power but interesting that it still gets some...a few gallons of E85 would zero that out most likely. This is in winter so winter blends which quite honestly suck and cause more KR than summer blends based on lots of logging on several vehicles I own. Not worth the cost for my wife to bee-bop around in but if I was towing or in the mountains, I'd run 93 based on these data. Feels the same to me but clearly logging indicates I'm getting a bit more out of the 93. Just say yes to data and no to butt-dynos!

View attachment 166412

Out west we don't get 93 and 91 is so bad frankly I just dump it in everything regardless if they run on 87 or not.

 

[SwampSurvivor]

A number of car magazines have tested this over the years. One was with a Porsche 911. The premium fuel even with the price gap was worth the extra money due to performance loss on the cheap stuff.

My father tracked MPG using 91 ethanol free and 87 Octane e10 on their 2013 Escape (2.0L ecoboost). The 91 ethanol free saw enough of a fuel economy improvement that it would save a bit of money. Something very miniscule. Like pennies per thousand miles.

 

[Plawan]

I enjoy watching PF.

 

[TiGeo]

I enjoy watching PF.

Not permitted here.

 

[4strokes]

I just thought of something. Our 2018 1.5T CRV doesn't fuel dilute, at least I never caught it in the act. Around 80K miles IIRC.

We only run top tier premium. Exclusively.

No problems with fuel dilution on my 21 CRV with 4000 mile oil changes at least by the level on the dipstick when changing the oil. I am wondering if maybe part of the problem with fuel diluation on the 1.5 turbo is the fuel injectors which seem to be prone to premature failure.