I am quite sure this is a question that has been asked about 10 thousand times in here.

I am new to powerboating from racing Personal Watercraft. So I am learning as I go. My Merc owner's manual recommends a single grade Merc Performance oil for my engine. I have seen that a lot of you are running Synthetics, which I too prefer. I have also notice that a lot of you are running multi-grade synthetics instead of a single grade.

I am going to change to Mobil 1 for sure. What grade should I use in my 502 Mag?

Thanks for the help.

Buck
#183

I use 15w50 Mobil1 and a M1-302 Mobil1 filter on my 454 MAG MPI.

Hi Buck!

Did you get her wet yet (The boat)? I like the Mobile 15W50 too, I'm probably not as fussy as I should be on the filter- been using AC Delco, will get something better for next change.

When are we going to hook up on the water? I sam Chris last Sunday (22' Donzi). I had to burn some fuel off while Easter Dinner was cookin.

Ken

I run Val 20-50. The racing stuff. I would like to use synthetic, but the previous owner didn't. Is it ok to switch? Should I start with a blend and then move to fully synthetic?

Now you've done it. Pandora's Box is wide open again!!! Stand by for a wide array of opinions and controversy!!!

I'm with Nabber on what I use in my motor. Can't go wrong with the Mobil 1 15w-50 and a good quality filter.

Buck183,
You can switch any time ya want to.

Now you've heard my .02, and I'm sure there's more to come.

Hey Nabber,
you sure that's going to be heavy duty enough
Tell Bob I said hi and be careful with your new toy
Dave

Kendal 20 50 put up the best hp on the dyno at burke power

Catt,

Nope, haven't splashed yet. Going to parents house tomorrow to get her out and clean up. Will probably splash in two weeks. Having couple of chips repaired on my gel coat next week. You'll be hearing from me though!

Laveyman,

Thanks for the heads up. I wasn't worrying about switching over. Just worried about which grade to use. Switching was going to happen either way.

It looks pretty unanimus though, 15w-50 it is. It was always going to be Mobil 1. Just wanted to know what grade.

Thank all!!!!

Buck
#183

if you have a lot of time on a motor with conventional oils, when you switch to synthetic, you may get some seeping around some of the seals. Conventional oils will allow sludge to build up inbetween the wipers on rotating seals and the more effective detergent action of the synthetics will "clean" those deposits away, leaving you with leaky seals. Granted this is more of a concern on a high-mileage car motor than a boat - marine applications run at a higher rpm and stay cleaner inside. Have witnessed the highmile leak in several applications in autos though. Also not recommended to use synthetic during breakin.

Use Mobil 1 15-50 oil. best filter mobil M1-302 then AC 1218.
Just my 02