How many of you are using synthetic oil? What is your preferred brand and why?

RD

i started using royal purple but have now switched to amsoil.

Run Amsoil in everything I own. Reason for Amsoil is that I have been running it in sleds for years with no problems...plus can't beat their extended drain intervals.
8.1

I have used Mobil 1 for years and switched to it on my truck at 720 miles. I've used it in all my vehicles from day one that I get the vehicle home and have never had a problem. In the far north, you need it so the truck will crank over a little easier when the mercury drops below zero.

I've never had a problem with seepage, weepage, or oil usage on any of my vehicles with Mobil 1. I use Royal Purple in the motocross racing bikes we have that my son rides and it holds up very well to the abuse...but for my trucks, it's Mobil 1.

On my 2000 Silverado 1500 5.3L I used Valvoline Synthetic for 50Kmiles and switched to Castrol synthetic until I traded it for my DMAX.

Never used anything but quaker state synthetic the only down fall i can see is if you have any leaks it will leak a little more

I use Mobil 1 in my wife's suburban so she can take it to wallyworld if I'm not around and have it changed. Only use Amsoil in the Dmax.

at least when i was looking, Valvoline did make a synthetic 15-40w. i love valvoline, have used it in all of my other vehicles untill the old d-max

I use Valvoline Durablend 5w-30 in my wife's '04 Sub 2500 6.0L. It's not a true syn, and using it makes me feel a bit better, not to mention it's half the price of true syn. Rotella syn 5w-40 in the 3500 Duramax.

JP

I use Castrol 10W30 synthetic in my 2001 2500HD 8.1, Transyn in the Allison and GM's synthetic in the rear end/

i meant to say that valvoline does NOT have a full synthetic 15-40. they have this stuff called blue or something like that, never used it though.

I use Amsoil 5w-30 synthetic for mine.

I am running Amsoil 10W-40 in my truck. I have been running synthetics sense my truck had 6,000 miles on it. I now have over 85,000 on it. A good synthetic is the way to go IMO...