Your "operators manuel" should explain which type of oil to use. I have a 96 Buick, LaSabre, that uses 10/30 wt.
check your manuel
what size of car battery do i need for a 2003 buick lesabre
body lift
DextronDextron
R 134A (hint it is also in your manual)
10w30 says it right on the oil cap.
The 2005 Buick LaCrosse has a 4-speed automatic.
this new type of gas called butt gas
Your hands, your hands
If your car has 100.000 miles on the engine,it's best to use 50 weight racing oil. My 90 lesabre has 293000 miles I use 10w30. Thicker oil will not flow to the bearings as quick and is not recommended by GM.
The 2005 Buick LaCrosse runs on regular unleaded.