Does Synthetic Improve MPG?

[dlundblad]

To those of you who notice improvement, how do you calculate the averages?

Just 1 tank or the duration of the OCI? Pen, paper, same fuel and pump or the MPG calculator on the car?

There is more more to MPG gains/ losses than oils IMO.

 

[JerryBob]

Originally Posted By: wemay
Originally Posted By: Doog
If you plan to keep it past 150,000 miles then you will reap the long term benefits of a synthetic oil.


You don't truly believe only synthetics can get you over 150k miles w/o issue, do you?


I was kind of scratching my head with that, too.

 

[BlueOvalFitter]

Originally Posted By: Blueskies123
I only run synthetic to extend OCI. I break even on the cost with the extended OCI but I save the time and hassle of an oil change assuming you consider changing your oil a hassle.

"RUMOR" has it that PYB contains some of the same base stock as its PP and PU counterparts. And, it's less expensive than a synthetic oil. I am sure it can be changed at a 10K mile interval, just the same as most synthetic's on the market. Opinions?

 

[Garak]

Originally Posted By: dlundblad
To those of you who notice improvement, how do you calculate the averages?

One is going to be extremely hard pressed to find improvements above the margin of error. I demonstrated some time ago the math of the issue in a thread here. An automaker has the resources to eliminate a bunch of variables and do proper testing. The general public does not. There certainly is a difference, but there's too much background noise for you or I to tell the difference.

 

[wemay]

Originally Posted By: Garak
Originally Posted By: dlundblad
To those of you who notice improvement, how do you calculate the averages?

One is going to be extremely hard pressed to find improvements above the margin of error. I demonstrated some time ago the math of the issue in a thread here. An automaker has the resources to eliminate a bunch of variables and do proper testing. The general public does not. There certainly is a difference, but there's too much background noise for you or I to tell the difference.


Completely agree with Garak. We do not drive in a controlled environment so cannot conduct controlled experiments.

 

[CharBaby]

I find it very difficult to improve the factory MPG with just synthetic oil. I have never gotten better MPG with syn alone(over the whole OCI). It's still about the same as with dino, overall!

To improve on MPG I find that if I drive slower, this is where I get my best MPG. I've even tried over inflating my tires(within the safe spec) and haven't seen any better MPG either. And, removing the rood racks have NOT improved the MPG either. Even when I did all 3 things mentioned(syn, >PSI, racks) together, I noticed NO MPG improvement.

And I check my MPG on every tank of gas. I have since the 70's! I've had cars that met the EPA rating and others that couldn't no matter how hard I tried. We've even had cars(Mazda3 in sig) that smashed > the EPA MPG rating by quite a lot. To the point that we had to check the Odometer/Trip Sets with GPS to make sure, the MPG was that good!

 

[CT8]

The energy saving oils are supposed to equal the mpgs of PAO bases oils.

 

[Lex94]

All else being equal, a more saturated base oil will have less friction and therefore better MPG.

 

[Garak]

Originally Posted By: wemay
We do not drive in a controlled environment so cannot conduct controlled experiments.

Wind and temperature are our worst enemies, not to mention that if one wants good results, one should be using exactly the same fuel all the time for many tests. That part isn't even feasible with batch variation, not to mention seasonal formulations, or regional formulations for those who travel enough to put on significant mileage.

 

[FutureDoc]

Actually, you can control for margin of error... you just need a lot more samples. Not practical if you want to know if YOUR car with YOUR oil choice. Even then, it is not generalizable.

I would say you could get a minor bump but a lot of engines might not notice it as much. It would be a "real" froghair... it is there but not easily felt. Lets say if you get a 2% bump (a lot but common claim for the 0wXX oils)... that might be 0.3mpg for a 15mpg vehicle but 0.8mpg for a 40mpg vehicle. Then it comes down to how many miles you can book as far as the cost savings. So, if you take that 15mpg vehicle and drive 15K at $3 per gal, you will spend $2940 compared to an even $3K... so it would pay for itself in fuel alone even if you you do 2x 7.5K OCI vs 5K OCI...but that is assuming a 2% bump and the mileage.

However, if you want better mileage... there are a LOT of driving behavioral items to address but if you are hypermiling, go syn with as thin as you can go.

 

[Garak]

Originally Posted By: FutureDoc
Actually, you can control for margin of error... you just need a lot more samples. Not practical if you want to know if YOUR car with YOUR oil choice. Even then, it is not generalizable.

Yep, that's the big problem. One of us trying to do a lot of samples isn't practical, and those who drive huge highway miles are buying fuel from different jurisdictions with different ethanol rules (or other formulation issues). Or, as time passes, winter blends and temperatures play a role.

As has already been mentioned before, yes, going to a GF-5 0w-30 in a 5w-30 or 10w-30 vehicle will have real savings. Noticing them is just this side of impossible, though, but that doesn't mean they're not there.

 

[TiredTrucker]

There is a lot of documented evidence to suggest synthetics do provide some fuel economy advantages, but not as great as the marketing folks would suggest. It all depends on the application. Whereas a typical car getting maybe 2 tenths better mpg is hard to quantify, in a 2000 truck heavy commercial fleet that shows an overall improvement of 2 tenths mpg per truck is dealing with thousands of dollars per year per truck in savings. Just 1 tenth mpg improvement saves $800-$1000 a year in cost of just one OTR truck. And the way those numbers are tracked and such is more realistic than they typical auto owner.

 

[BillyTheKid]

No it does not improve MPG, you would never be under a controlled environment to enough to prove it.

 

[turtlevette]

There's been much discussion here about MOS2 increasing fuel mileage and people aren't jumping all over them.

 

[raytseng]

It should be the same out of the bottle or arguably close.

However, where a bigger difference maybe seen at the end of the OCI, assuming you are running at a long enough OCI that the conventional is closer to being fully out of spec; while the synthetic still is serviceable.


But as the calculations also show for the total cost of ownership, running synthetic anyway is also arguably close in cost too...

 

[Tony10s]

Originally Posted By: Garak
Originally Posted By: dlundblad
To those of you who notice improvement, how do you calculate the averages?

One is going to be extremely hard pressed to find improvements above the margin of error. I demonstrated some time ago the math of the issue in a thread here. An automaker has the resources to eliminate a bunch of variables and do proper testing. The general public does not. There certainly is a difference, but there's too much background noise for you or I to tell the difference.


I agree with Garak on this.