@FicoMike0 wrote:
Great tip on the m1 rebate!
I seem to recall that synthetic oil is actually made from natural gas.
That's Pennzoil Platinum and Ultra Platinum that are made from natural gas.
I use those in the Buick usually but would also use whatever I can get a good deal on.
I also have some Castrol GTX Full Synthetic and some Castrol Edge from from various rebates right now.
Unless this goes on for more than two years I'm good.
My Buick 3800 takes 5w30.
The only other viscosities you could use without risking damage are 0w30 and 10w30.
0w30 is good for extreme winter days, but not ideal to use any other time of the year. The only benefit is faster oil flow when it is subzero temperatures. So unless you can't find anything else on the shelf, I wouldn't bother using it except for about December through the end of February.
It won't damage anything, but so far I've only seen it for Euro car formulations, Mobil 1 (not dexos approved), and FRAM at Advance Auto Parts.
10w30 does NOT flow well in cold temperatures. You should not use it from December through May in the Midwest on any 3800 that calls for 5w30, otherwise you can get away with it. If you're very desperate you can use it in the winter, just realize it will cause upper engine wear until the oil gets going.
