Using 5-30 in a car that is spec'd only for 5-20?

[kokopelli]

LOL! no, I liked them. Charts are always good... LOL...

 

[BuickGN]

I've used 5-30 in the TL for a long time. Now running Amsoil straight 30 just to freak people out. I do mostly freeway running where the car is driven continuously for 4 hours at a time and only gets started a few times a week.

 

[rponfick]

The oil recommended in the owner's manual has to be the same as the oil used by the manufacturer during it's EPA CAFE standards testing. Naturally the manufacturer want the highest mileage figure possible (being the lightest weight oil)for advertising purposes, but this may not be best for engine longevity.

 

[pbm]

I have often used 5w30 and 10w30 in my 5w20 spec'd Accord with no issues. However, sometimes I feel the engine revs more freely when the sump is full of 5w20.