GT1999

maybe the thicker oil is to account for the warmer weather... im not sure if this make sense but when its colder i assume that oil maintains a thicker form.... and in cali its usually warm , coldest ive ever driven in was probably 48 degrees... so i figure since its usually warm , it will make the oil less thick, and putting a 30 instead of a 20 will maybe account for the thickness that the weather plays a roll in ? lol i dont know if that makes sense... i had a hard time putting it into words... but still, my manual says 5w30.

ITALIANO66669

thats funny.i live in louisiana so maybe as you said being a california car maybe it is different yall have funny things going on out ther ya know.lol.my manual says5-20 just a bit of a mix up.

Aixtreme89

Check the oil filler cap on your calve cover. On my 03 GT it is printed 5w-20 right on it.

Soaring

Yep. same on my 03 32 valve Mach engine. 5W20. There is no difference from the factory for a Kali car or a loser anna car.