Fuel economy / power difference 5w30, 0w-30 0w-40

[Mitch Alsup]

Originally Posted By: M6ser
do you think there will be noticeable fuel economy or engine power feel difference ?


If you take the engine out of the car and put it on a dynamometer, you have a pretty good chance at being able to read a HP gain.
If you leave the engine in the car you have a very low probability of feeling any difference.

As to fuel economy:
A motor oil can deliver 2%-3% gains.
A change in driving habits can result in 20% gains.
So your driving habits are 10× what the change in oil can deliver and can EASILY swamp any change in oil.

 

[Jetronic]

and, the worse your driving is (efficiency wise) the smaller the % gain is that you can get from a change in motor oil. Reduced friction only works against parasitic losses, not against braking and aerodynamic losses which is where the majority of excess fuel useage goes to.

 

[Shannow]

Early days of my turbo-diesel Nissan (2003-2005), before I gave up chasing economy through oils...the Castrol was 12.9cst, so I guessed that it would have been best for economy...

then gave up.

 

[BobsArmory]

I have run nearly the full spectrum of oil weights thru my Silverado. M1 AFE 0w-30, 5w-30, 10w-30, Castrol European 0w-30 & 0w-40 even some Maxlife 10w-40.

I have never been able to tell the difference in mileage or performance.