Ive started using Amsoil....
 

Hey guys, I just switched over to Amsoil HD 15-40 and and right away the truck runs smoother. Im hoping to see a small MPG increase too. Now for a question. Im realy thinking about running Amsoil in the drivetrain too. Have any of you done this and did you see any additional MPG increase? It would have to free up some extra power too.
Thanks for the input!

Believe you may be imagining the running smoother and getting better MPG. Then for the price you paid, I'd find some way to justify. IMHO there may be a case for SYN oil for protection at higher temps and extreme service, and more particurally longer service intervals. If you need these.

I also switched over a fews months ago to Amsoil's Heavy Duty Diesel & Marine 15W-40 with the Ea080 filter.

It runs alot smoother!

Been running the stuff for years in everything I've owned with pistons and gears.www.amsoil.com some vehicles I got a increase in mpg small but some.Others stayed the same or to small to measure like the reassurance of top quality lubes and length of time you can run them.Also like that big brown delivers to my door in 24 to 48 hours after order.Become a preferred customer and save some bucks on it.

I may do that. Might as well save the cash. [coffee]

Just switched from RP to Amsoil. My oil analysis wasn't good from Blackstone, and with 12k on the oil. I will be posting this up in a new thread later. On note I am liking the oil so far, but haven't really noticed no difference over the Royal purple.

Edit: my bro-in -law is a dealer so i can get the discount. But I may switch to Delo or Cummins premium next go around if this analysis doesn't get better. Why spend so much money if it won't help any more than dyno oil. I know what statistics say, but this is the way my truck is, and alot of others.

I doubt there would be much of an improvement in mpg running the Amsoil Marine 15-40 over other oils of the same weight. There is supposed to be some measurable increase when you use Amsoil HD 5-30, probably due to the lighter oil being easier to pump. Four ball wear tests are just about identical for these two oils. I would have a hard time justifying the extra expense of synthetic oil unless you run a bypass filter and do oil analysis so that you can increase your change interval.

i get 20,000 miles out of my oil change using amsoil 15w-40 oil and the single bypass setup