Anyone using this in their boats? I run the 15w 50 and it gets black so quick I think it's bypassing my filter too much. Would this oil help out on that. I'm also running the mobile one filter.

I would stick with the 15W50. Your oil darkening up quickly is most likely the byproduct of running too rich.

i run the mobil 1 delvac 5 - 40 and it is spectacular

What is your oil pressure?
I run the 15-50 with great luck. When my engine is hot I see 20-25lbs at an idle and 45-50lbs at 3000+rpm.
I believe the bypass in the block is 30lbs so there is always some that will bypass the filter and cooler.
Do you have a blower bolted on top?
If yes, your oil will get dark a lot quicker.

Yeah, I know that probably got something to do with it.

i have box stock 502 mpi. op is 50 at spped and 25 hot at idle

5w40mobil1 is the standard oil that Mercedes Benz is using on all there cars now, we use it at the dealership i work at on gas and diesel engines

The first time I ran Mobile 1 in one of my engines, it got darker than the other engine that I ran dino oil in. I wanted to see if there was a difference. I was thinking maybe it cut some junk loose that dino oil left behind. Other than that, no difference in pressure at all.