FYIOriginally Posted by Mentalpause
I talked to the sales rep at Illmor a few months back. The Viper uses 10W-30 Mobil-1 and the Illmor marine conversion 10W-40 Mobil-1. I was going to get a pair as a power upgrade but you need new drives too. The engines put out too much torque for a bravo 1 so imco's or platinum Teagues or #6's which is what they were originally tested with is what ya need.
I am beginning to think 10W-40 Mobil-1 is probably fine for most marine engines. It doesn't shear down. The new 5W-50 Mobil-1 may be a good choice as well. I would save the 20W-50's for engines that have been tuned and are pushing the limits. Mobil-1 15W-50 is fine of course. Just my .02