Rotella 15w40

I'm not a big fan of using diesel in gas engine. Even Shell does not recommend it.

No reason to use a 15/40 in most vehicles either.

I had a Ford van with a 351 gasser . Bought it with 105k... Sold it with 485k. Tried Citgo 10w-30...used too much and the oil temp soared. Went to Mobil1 10w-30 after the first change.

I have 30w CenPeCo for my race motor. I use a single grade for the alky motor.