2000-2003 LeSabre 10W-30, 2004-2005 LeSabre 5W-30

[Merkava_4]

All 5 of those years used the Buick 3800 V6, but starting in 2004, the LeSabre gets the new
3800 Series III V6. You guys got any comments as to why they'd spec 5w30 starting in 2004 ?

 

[ls1mike]

Probably gas mileage 10w30 is fine in that car. 3800's are very easy on oil.

 

[chubbs1]

I agree with mike. It is due to fuel economy. Either oil will work fine but why not use a good 5w30. The market changed rapidly for PCMO's as I remember. 10w30 was the recommended grade for a long time, then 5w30 was the staple, quickly followed by 5w20. Now we see 0w20 becoming more common. It will be getting thinner in the future, most of the major Japanese manufacturers are already testing 0w15's. JASO is trying to iron out spec's with the API, SAE, and the majors on "how low they can go" before engine wear becomes a problem.