50 weight engine oil

[Constant Mesh]

Should there be any noticeable MPG difference between 15w-40 and 20w-50 engine oil? I used 20w-50 in my last change and it appears that the MPG dropped a small amount. I've also noticed at a cold start that the rpm is a bit lower with the 20w-50.

Honda recommends 5w-20 for my cars. I assume they recommend this oil in an attempt to get the most MPG.

 

[Nitro]

Should there be any noticeable MPG difference between 15w-40 and 20w-50 engine oil? I used 20w-50 in my last change and it appears that the MPG dropped a small amount. I've also noticed at a cold start that the rpm is a bit lower with the 20w-50.
Honda recommends 5w-20 for my cars. I assume they recommend this oil in an attempt to get the most MPG.

Yep 5W20 is for M.P.G.

 

[escapefjrtist]

FWIW, I've run both the Xw 40 and Xw 50 and haven't noticed any difference in mileage. Only noticeable change was in cold cranking at 26F...

--G

 

[dcarver]

Where is Jestal when you need him?

Jestal? To the white courtesy phone please!

 

[FJRBluesman]

You are correct mileage will drop.

Never use energy conserving low viscocity oil in your FeeJ motor. :nono:

 

[RadioHowie]

How about using Mobil One 0-20W?

 

[Geezer]

More than you ever wanted to know about motor oil.

 

[radman]

How about using Mobil One 0-20W?

Car, maybe, bike, never. But you knew that. 0-20 is purely CAFE driven, although new motors have very close tolerances these days. 5-30 is as low as I'll run in a car, 10-30 preferable in warm weather. Have run 15-50 M1 in Frank forever, he loves the stuff. 10-40 M1 in cold weather eases starting.