Ethanol Free Fuel

5W-30 in the engine, right? (Running oil that's too viscous robs power and reduces mileage.)
I run Amsoil Severe Gear

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in my transmission, differentials, and transfer case. Again, running gear lube that's too viscous robs power and reduces mileage.)

That makes sense. It will probably idle down under 1K RPM when it's warm.

Based on everything I've read here, I think your single biggest "problem" is your highway speed. I'm not sure there's much you can do to improve your mileage, aside from slowing down a bit.

 

Well what gear do you recommend for my transmission and my rear diff?

And how much would it help mileage wise?

 

Like others have said, keep it under 70mph, ease up on the acceleration and you'll see a dramatic gain in mpg's. E10 fuel lowers your mpg by 3-4% on average [source], so a vehicle getting 20mpg on pure gas would get 19.2 or so on E10. The advantage to E10 is that it lowers the amount of CO and other pollutants by more than 3-4%.

 

Sorry. I should have been more specific, and just edited to say I run Amsoil Severe Gear

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in my transmission, differentials, and transfer case. 5W-30 is appropriate for your engine.

Mileage improvement from the transmission and rear diff lube would be marginal. The only real solution to your original problem is to slow down.

 

Try this site to find ethanol free fuel in your area. The site relies on user input to add or remove specific stations leaving its' accuracy somewhat compromised.

http://pure-gas.org/

 

E0 is good for about 6% better mpg.

 

depending on the tires you have i think your pressure is extremely low. i had my 265/65r17 tires running at 38psi before I noticed a cap in my mileage and the chalk test finally ran good.
door pressure was only for stock tires and best ride/handling ability. Honestly about 90% of max pressure on the sidewall of the tire should be about right. Give it a try and even though I promise a slightly rougher ride your tires will love you for it.

 

I agree but brace yourself.

 

let me hide behind my truck lol

 

Well I'll pump them back to 35 tomorrow then

 

Non ethanol fuel makes a very minimal difference at all in modern fuel injected engines. Other than making you feel better about using pure petroleum, you're just spending more money per gallon is all. Unless you are running and old carbureted rig or something that's souped up that requires non ethanol petroleum it's not doing much for your engine or MPG's. Stock, naturally aspirated fuel injected engines were designed to run most efficiently off of 85/87 octane gas with up to 10% ethanol mixture.