On a basically stock 454EFI in a 24ft Baja would it be better to use the 10W-40 Marine oil or the 15W-40 Marine/diesel HP oil?

Any input appreciated!
Michael

I use amsoil 20-50 severe racing oil

I would use the marine/diesal 15-40 in your engine,the 10-40 marine more for the 4stroke outboard,the dominator oil design for high hp application and should be changed more often
r

I was wondering if temperature makes a difference, my boat is closed loop cooled, but, I boat 'up here" in Ontario, Canada and at the beginning and end of the season the weather can be pretty chilly, so, I thought the 10W would be better, but, the recommended merc oil is closer to the
15W-40. I have been told that the "diesel" oils work well in marine applications, I assume since marine engine operate at a lower RPM and are almost always under "load"

Like I said, this is basically a stock motor other than exhaust and air cleaner, so, I am not looking to squeeze every last 1/10th of a HP out of it, but, want to use the best stuff I can to protect it,

Thanks!
Michael

I used to use the 15W40 Marine/Diesel oil in a 454 EFI with good results.

You go by the 40w, the 10/15w is for the cold start weight. You will never run the boat in that cold of weather to effect anything. I used to run the 15/40 when I had a flat tappet cam. This year I switched to the 10/40 marine, I really cannot tell any difference in pressure. I have a modified engine and I run about 15-20psi idle, 80psi cruise and above when hot (running temps).

Great, Thanks a bunch guys! I think I will go for the 15W-40sounds like its the way to go, Thanks!

Michael

Anyone interest in becoming an Amsoil deal or preferd customer, you can email me at [email protected] and will be glade to set you up.

I would recommend the Dominator 15w-50 Racing Oil. It doesn't need to be changed any sooner. I ran 60+hrs on the oil last year, and my analysis on it was still good to go. My second recommendation would be the ARO 20w-50 and my third and final recommendation would be the AME 15w-40. I would also use the EAO-25 Oil filter and if you have extra use the EAO 24 filter, its about an 1.5 inches taller.