2001 LAUNCH reccomened oil

[01launch]

Hi guys im sure this has been talk about more than once but i couldnt find a topic on it. What do you guys reccommend . I live in south fla where it is always hot and muggy all the time.

[2002 LAUNCH SS OWNER]

I think Indmar recommends 10/40 as the oil to use, I use my boat in a desert climate and I found the 15/40 I was using was not heavy enough at idle after running boat hard, so I now use Royal Purple 20/50 synthetic oil and oil pressure is better at idle now. Marine engines are like high performance engines the tolerence on bearing is set around 3000 of a inch compared to 1500 thou for a stock engine, this allows for more exspansion of metals as engine gets hot. Boats do not get to coast down hills, engines are always working hard. Mercruiser for years have used a 25/40 oil which is a modified 30 wieght oil, they now use a synthetic 20/40 oil which costs around 20 dollars a liter. So Royal Purples 20/50 at 12.00 a liter is a good deal, it is great oil** As for the tranny I use RedLine D4 Synthetic fluid it is approved for dextron type fluids, Mobil 1 Synthetic ATF is decent also.I would not use a 5/50 motor oil, 15/50 would be ok