Does Synthetic Improve MPG?

[JerryBob]

I am thinking of running PYB 5w30 in my new Tacoma, due to its 5k OCI, per Toyota.

It doesn't seem to make economic sense to run a 5W30 synthetic...unless there is enough of an improvement in MPG to justify the cost.

Over 5k miles, a 1 mpg differential will save about 11 gallons (21 vs 22 mpg) or $22.

Opinions? Will a syn of the same viscosity yield better mileage?

I am not agonizing over it - this is more academic than anything. Ok, well maybe a little.

 

[HerrStig]

Longer engine life. probably, better MPG, not enough to notice in most cases unless you make a drastic switch in grade.

 

[Doog]

If you plan to keep it past 150,000 miles then you will reap the long term benefits of a synthetic oil.

 

[Doog]

Originally Posted By: JerryBob

I am not agonizing over it - this is more academic than anything. Ok, well maybe a little.

yeah sure you're not

 

[hotwheels]

Originally Posted By: JerryBob
Will a syn of the same viscosity yield better mileage?


I expect a synthetic oil more likely than not to be a low friction oil. An inexpensive conventional oil is probably not a low friction oil, while a high quality HC oil most likely is a low friction oil.

hotwheels

 

[Jetronic]

the synthetic might also allow longer drain intervals, say 7500k. how much fuel do you need to save in that case?

 

[bepperb]

Of the same viscosity, and assuming the same additive package (all things equal) then no, it would not.

One can make an argument that many synthetic oils are premium oils with a better additive package that would have more friction modifiers, but this would be theoretical.

Also, an engine on 5k OCI of conventional oil will outlive the chassis by a wide margin. The idea a synthetic is required to drive a car past 150,000 miles is absurd. Like the moon is made of cheese or the sky is purple ridiculous.

The potential to save money with a better base stock oil is in a longer OCI (on oil) or a lower viscosity (better fuel consumption) but both are moot in your situation.

 

[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.

 

[sicko]

I run synthetic because if you get a couple OCIs worth when there's a rebate, it's usually the same price or less than conventional.

However, any MPG improvement is so minor it's not really noticeable.

 

[Vuflanovsky]

I switched to synthetic engine and gear oil in a previous car ( Mazda 3 )and got a consistent 1 MPG increase. Being that it was consistently 1.2+ , 1.4+, etc. over the course of many months with everything being the same, then I would say it's possible but it would be dependent on the application. In general, I view those amounts as close to ( although above ) chance due to driving conditions, seasonal gas, etc. It may be hard to quantify but I do think it's real to whatever degree. Likely not to make much of a difference if there's an expectation of 2-3 more MPG.

 

[CT8]

Can't hurt, but how many people keep their cars to engine life on new car purchases. As long as there is Easy financing people will be buying cars they shouldn't be buying.

 

[BrianC]

Maybe. But is it enough to detect. Given the variables under which all of us drive I doubt you could detect it during a tankful, or even many tankfuls. On a Dyno you might be able to tell. I'm sure the claims made by campanies are based on very controlled circumstances, not everyday driving.

 

[Quest]

IMO the gain (using synthetic) is negligible.

Also: don't forget that conventional motor oil sold in NA with the most up-to-date API service ratings are, in fact, a GpII+ blend, meaning that in true technical sense: they do come with a bit of GpIII and beyond in order to make the base oil meet certain API/ILSAC testing/certification criteria.

Q.

 

[Dyusik]

Absolutely! Run SAE60 and switch to RL 2wt and watch the mpg soar. Other than that, negligible. I choose film strength over the 1/25th mpg.

 

[jk_636]

Some people (myself included) have noticed an increase in certain vehicles when switching to synthetic. The results aren't groundbreaking, but it is possible. Good luck!

 

[CT8]

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.
There seem to be at least as many high mile vehicles running conventional oil as syn.

 

[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?

 

[Nickdfresh]

Originally Posted By: Quest
IMO the gain (using synthetic) is negligible.

Also: don't forget that conventional motor oil sold in NA with the most up-to-date API service ratings are, in fact, a GpII+ blend, meaning that in true technical sense: they do come with a bit of GpIII and beyond in order to make the base oil meet certain API/ILSAC testing/certification criteria.

Q.


You think it is "negligible". But even a small gain will be enough to offset the differences in price. Especially when you relate it to other advantages syn offers. My car's digitally tracked fuel economy jumped about .8 mpg (conservatively). That's about $35 a year in fuel savings at current prices and driving about 17K a year...

 

[Merkava_4]

Yes -- my MPG went up from 18.6 to 19.0 after switching to full synthetic Citgo.

 

[Nate1979]

Maybe. Maybe not. Probably. I'm not sure