Mobil #1 15-50 in whipple charged 500EFI.

I am afirm believer in Mobil 1 15W50 I have been running it in my 32 Fountain with 500 HP's for years, and swear it gives me more RPMs' My boat is a 1995 model and I have beaten several later model Fountains with exactly the same engines and deeper stepped hulls that should be out running me.

What That is all you are going to say. If you have some "first hand" test data that could prove beneficial.....why not share it.

Why Royal Purple ? Are they a sponsor Yes that was a shot

I have a couple of brand new 500EFI's and want to maximize their life. I also know that oil and oil changes are the best way to make that happen. I have installed a pre-lube system on the boat.

I am leaning toward the synthetic, but have had excellent experience with Valvoline in boats and cars. That may simply be a function of regular oil changes and not the oil itself. But determining the best Syn. to put in the boat is the tough one. Mobile 1 has changed their blend, then you have Red Line, Amsoil and Royal Purple all saying they have the best.......I am having trouble making a decision

I use mobil1 15-50, it is better than regular oil and I get it for free, but i will most likely switch to redline are royal purple, the reason, these are the only two oils that have Polyolester in it, yes it is spelled right not polyester.
Polyolester is used for turbines, such as jet engines, it gets ride of heat better than anything else, that is why these two oils cost more than mobil1 are the other syn. oils on the market.
I am also a Mercedes Benz tech, we use to have some cam wear when we started using mobil1 back in the 80's, mobil1 has changed it formula several times since then, today, their is no wear problems at all, all new Mercedes and Porsche's come with it from the factory, on the 112and 113 engine they have roller rocker arms[overhead cam] and no wear on them on tear downs, we are going 11000 up to 14000 miles on an oil change[flexible service system] and the mobil 1 is holding up, we had a few customers switch to regular oil when there warranty was up, the cars instrument cluster will tell you when it is time to change the oil,[Flexible service system] well they were going 11000 to 14000 miles on regular oil, guess what, the engines let go before the third oil change, the regular oil had slugged so bad it stopped up the pickup screen. so use what you like if it works for you, one of the keys here is to CHANGE your oil often