What oil would be the best for my boat? it has twin 350 chevys with about 10 hours on them.

I'm using rotella t 15w-40 in my twin 350 setup.

I just put a 540 in my mechanic said rotella has great cleaning agents in it.

someone told me to run 20w50 synthetic. does that sound right at all?

I run mine hard and like the Mobile 1 20-50W V-Twin synthetic. Ran my previous boat well over 500 hours on Mobile 1 with no issues. Another important item is the filter. Wix and K&N are good...stay away from Fram. Just my .02

Royal purple 20w-50 racing synthetic all the way! I swear by the stuff!

yeah i dont run anything besides wix filters.

I ran my Semi over 500k miles on Rotella 15-40 is the best oil I can recommend. I run it in everything boat mower pick up taurus power washer ect. I had a motor that ran mobil 1 and after 300k it showed significant deposits I was told that it was due to it being a paraffin based oil which rotella is not. FYI had a plugged strainer and maxd the oil temp the other day, no problems, Except stupidity.

Napa Gold are made by wix and are easier to find and cheaper. But you are right a wix product is the way to go!

Brad Penn racing 20w50. Several top engine builders I discussed this topic with agreed on it. They use it in their own engines.

Semi syn made from premium base stocks and loaded with zinc for anti wear.