Ok, ive spent hours researching this and trying to come to a conclusion. Ive got a 7.3l that does great with T6. Ive got a 540 that the wife DDs, and I recently got an 88 325i that I DD. M1 0w40 in the 540, trying to figure what to put in the 325; M1, GC, which weight etc....Now im wondering if...