I bought a 2001 Laramie 4 months ago with 190,000 miles. It had an intank lift pump and had never tasted 2 stroke its entire life. Over the last 4 mos. I've been working bringing it up to proper standards, ie, complete fuel system upgrade, electrical connections /grounds cleaned. Everything done has gradually increased mileage numbers with the big line kit, added pre filter, drinks of 2 stroke oil, but the biggest surprise was running the fuel return down the fill neck. This has helped most of all because air bubbles were getting sucked up the 1/2 inch draw straw.( explains my erratic fuel pressure readings prior)

Edited July 8, 20178 yr by JAG1

It's been a couple weeks now with the new fuel return location and the miles are still increasing. I did change brands of two stroke oil to a synthetic TCW3 bought accidentally. May have something there.

The 2 thing that increased mine were the RV's and the Comp. I got right  at 2.25 MPG combined. The RV's alone were a very nice addition and the comp got the mileage up running 75 mph or so down the interstate. 

 

I'll be interested in how this turn out for you.

I still have fuel fluctuation a little. Not like before, so  I think I still need to bleed  air out the top of the pre filter. Gets trapped up in there. Racor provides a bleed off for that.

 

Any thoughts on synthetic 2 stroke oil?

2 hours ago, JAG1 said:

Any thoughts on synthetic 2 stroke oil?

Probably lube about the same and cost about twice as much. 

 

 

4 hours ago, JAG1 said:

I still have fuel fluctuation a little. Not like before, so  I think I still need to bleed  air out the top of the pre filter. Gets trapped up in there. Racor provides a bleed off for that.

 

Any thoughts on synthetic 2 stroke oil?

I dont know much about it myself but might have to agree with @IBMobile. But if you are seeing a difference I would hard pressed to change. Like me and bio diesel, my truck loves it. I have seen over 22 mpg running bio MASS diesel. I have only found 2 stations in Tenn that have stickers for that on the pumps. I just know when i run it my mileage is up. Unlabeled and bio diesel labeled pumps I am right a 20. I cant explain it but the improvement is there. 

3 hours ago, IBMobile said:

Probably lube about the same and cost about twice as much. 

Actually the price was a deal is the only reason I bought two cases. When home I realized it was synthetic.

On 7/8/2017 at 0:44 AM, JAG1 said:

This has helped most of all because air bubbles were getting sucked up the 1/2 inch draw straw.( explains my erratic fuel pressure readings prior)

That's why I had to make sure my return lines were returning all the way to the bottom of basket, maybe 1/4 inch of bottom. Otherwise if it's few inches above it creates foam if tank gets low. If return lines are submerged in fuel it should not create air angles you're sucking it somewhere in system. 

Both of my return lines, engine and lift pump, go to the basket. I dont remember how low they go though, but my AD is suppose to return all the air pulled into it back to the tank. So either I got them very low or the AD works as it should. The only air problems I have ever had are from leaks somewhere else.