Thread: Manual says 10w-30

Why does the manual for my 03 GT say to use 10w-30 when almost all other cars of that vintage say 5w-30? The oil cap even says 10w-30 on it. 01 and older and 04 and up Grand Prix's say 5w-30.

I live in the Minneapois area.

Oil has come along way since 95 when the first gen 2 motor came out. They wanted more oil pressure is pretty much what it came down too. Though them fully warmed up, the viscosity was the same as 5W30.

The gen 3 motor got a better oil filter housing design aswell as a high pressure spring.

So it doesnt really matter what oil you run, but if you live in the cold, run 5W30 in the winter to help the motor out and run 10W30 in the summer.

Originally Posted by Curious

what about 15w40?

Sure if your grand prix is a diesel.

Originally Posted by Fivefingerdeathpunch

Sure if your grand prix is a diesel.

*like*

Sent from my HTC Thunderbolt using Tapatalk

0w-30, 5w-30 or 10w-30 are all ok to use. I use 5W-30 all year round.