The other day we were pulling a long and stopped and filled the main tank only at a Flying J and just like 2 other times before the fuel mileage dropped and so did the power. Topped back off at a Casey's from 1/4 tank and all went back close to normal. I'm just glad I didn't put any in the aux tank like I did before and had a lot of crap fuel. The only reason I only topped off the main tank was because one of the couples we were traveling with didn't have a aux tank so we stopped a lot for fuel. Today because we are by ourselves now I transferred some Cenex fuel from my aux tank and it's running even better, getting the crap gas blended out of tank.
Denny

 

When I saw the thread title I thought it was a warning to us arguing about motor oil or gas vs diesel

 

But anyway....that's interesting I thought all gas was the same but now I wonder.

 

The only other brand I've had problems with is Sunoco, one time in Virginia and once in Florida and I haven't used it sence. The computer used with the 6.2 works so good that unless you are pulling or not watching your average mileage it's hard to tell. I've used other off brands and haven't had problems that I could tell anyway, I'm really thinking they are using more than the 10% alcohol listed on the pump.
Denny

 

Use ForScan and see what the % alcohol says. The stations say up to 10% here but my truck typically shows 6-7%.

That said, I don't like flying j or pilot gas or diesel. I've had bad experiences with both.

 

I have been thinking about an aux tank for my 17 6.2. What do you have and how do you have it hooked up? I was wondering if the safest and easiest bet would be to use a tank with an actual pump handle. Thank you. Love reading your posts.

 

..

In Ohio.. I have had gas issues with several Sheets gas stations.... engine ran OK.. but gas mileage was down by 50 percent...

remember most stations can ask for different mixtures... from the same Brand...

 

This is installhttp://trucks.com/forums/1251254-my-aux-fu
Denny

 

This is my tank install, I did have to change the vent line to open air with a filter on the end because of the cap test, it would set off a code when the tanks were close to empty .
https://www.ford-trucks.com/forums/1...k-install.html
Denny

 

Using a tank with a pump/handle just defeats the purpose of an aux tank. You'd have to stop/pull over to fill up your main tank.

 

I've never used lot of top tier gas in the past but after my Flying J experience I used only Shell and Exxon and to my surprise I gained over a mile per gallon, I was struggling to get 8 before and now 9+ is the norm pulling. When we head back west in December I'll see if it stays that way.
Denny

 

Sounds like they had e85 in the regular tank.