hey guys,i have a new 509ci in my 24ft outlaw and i can not deceide on which oil to use in the engine,the guy i got it from says mobil 1 but i am not sure,i used royal purple in my old engine with no problems,also does anyone have an oil temp gauge in their boat,and what does it usally read?

Pennzoil 20W50

Mobil 1 15W50, Mobil 1 20W50 V-Twin, or Royal Purple 20W50 would all serve you well.

Dean,

Why do you recommend a petroleum oil over a full synthetic?

My motor guy used to swear by Pennzoil also but I've been told it's been reformulated and not the same as a few years ago.

Here we go again, another oil debate!

Ak,
Why would you not use the oil that your engine builder specified ? If the engine has a warranty, the only advice you follow should be that of the engine builder.

That being said, my choice would also be Mobil 1. Royal Purple is probably of the same quality, but its a bit overpriced in my opinion.

Just my opinion,

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

I have been very happy with Mobil 1. After I switched to it in my 502mpi's, my oil consumption was cut in half.

Oil temp gauge is as important as a water temp gauge! Keep it under 240-250* and everything should be good. I change my oil so often I don't think it matters what i run.

Mobil 1 Synthetic 15w-50. Never used anything else. I have 12 qt. oil pans. But in the whole scheme of things, its only a few bucks extra to go with the best. When I pull out those 12 quarts after 25-30 hours. It looks like brand new. I keep it and use it in my tractor, lawn mowers, etc.

If you want everyone's opionion on this topic, do a search. There are about 30 threads on this

Synthetic it the way to go.. As far as name beand the common names you hear like Mobil, RP, Castorol, etc.. are all good oils..

Jamie

SuperTech...you can get it at Wally World for the best price. I think they make a synthetic, and a "high mileage" version too. 10w40 or 20w50 depending on clearances and temps.