Which synthetic oil do you use in your cars, boats, trucks, motorhomes, etc...? I think there are alot of good ones out there right now.

I use M1 in everything. I have gone the Amsoil route, as well as a couple others, but the differences are little between M1 and the rest and I can buy M1 in town just about anywhere so I don't have the mail order headache or stupid high prices.

I use M1 in boat and my Mustang. My truck and wife's car get conventional oil. I would probably try another synthetic, but the M1 is priced right and readily available at Walmart.

I like the Royal Purple and have run it in many gas engines and my last boat and haven't had any problems with it. I change the oil on the gas car engines at about 8k miles. When I watch the oil comming out of the bottom of the pan after 8k miles, it's never burned or anything.

Wifey's Benz gets serviced at the dealer and they use M1. I use Amsoil in everything else; mainly 'cause I can get exactly what I want and it's delivered to my doorstep. With the preferred customer discount it's fairly competitive price wise.

Mobil 1 15w-50 in the boat.
Synthetic Rotella T 5w-40 in the Dodge/Cummins.

Actually, I have a firiend who is a distrubutor for Amsoil, and I get it cheaper than Mobil1 @ walmart! Right now, I'm running Lucas syn, that I got a killer deal on from Mystic Powerboats! Seems to be fine, but then again, I've hardly run the Nordic this year, between work, $$ of gas, and all the other crap that gets in the way of boating these days.

Amsoil Dominator 15w-50 is the one.

http://www.amsoil.com/storefront/rd50.aspx?zo=1132530

i use royal purple in everything. including my lawnmower and powerwasher.

i use royal purple because it is easy for me to get (i sell it where i work). any synthetic oil is better than conventional no matter what brand.

i also sell amsoil, redline, and more recently roush racing oil.

I run amsoil oil in all my stuff, boat, truck, car and snowmobile.