Fuel quality at different stations

I've driven diesels for essentially my entire adult life, and after spending ~5k on a new fuel system a couple years ago on my F250 because of poor quality fuel, I've only ever got diesel at the most expensive place in town, which is Shell. I was in a trip a few weeks ago and had to get diesel at an Exxon station, and noticed the entire way home my mpg went from 32-35 to 25-26. This was with ACDelco additive too. The whole rest of that tank my average was 25.7 mpg. At 1/4 tank I got Shell diesel again and my milage instantly jumped back up to 28-29 city and 32+ highway.

Anybody else had this happen? I've never noticed anything that dramatic in any other diesel I've ever had and I've had 5 different diesel vehicles. This engine seems extremely sensitive on fuel quality.

Are you sure you didn't get B20 at the Exxon station? You will get less MPG running a higher concentration of bio-fuel. You might also have gone through a regen during that tank of Exxon and that will bring down the MPG as well.

The difference from the worst fuel (assuming uncontaminated) and the best fuel really isn’t that far. Other things had to affect your mileage.
Ive used everything from the corner station to Amoco, BP, and Shell.
No additives, not necessary in my book, and mileage doesn’t vary 5%.
How and where I drive it has way more to do with mileage than lower or upper grade fuel, IMHO.
Change your filter 2x as often as recommended and that will go a long ways toward warding off fuel related issues….

Stbentoak said:

The difference from the worst fuel (assuming uncontaminated) and the best fuel really isn’t that far. Other things had to affect your mileage.
Ive used everything from the corner station to Amoco, BP, and Shell.
No additives, not necessary in my book, and mileage doesn’t vary 5%.
How and where I drive it has way more to do with mileage than lower or upper grade fuel, IMHO.
Change your filter 2x as often as recommended and that will go a long ways toward warding off fuel related issues….

Click to expand...

new to 3.0 ownership. Is the filter an easy DIY job? Or dealer screw job only?

Easy peasy - it's the exact same filter setup also used on the 6.6L Duramax.

Holy shit.....so about 3 weeks ago I filled up and I didnt remember where but starting the next day I was actually watching my fuel needle go down incredibly fast for the next few days. Im like 'WTF'....not that I get great mpg on my 06 but this was ridiculous....after my next fill at a different station i went back to normal ****** mpg.....
im glad to hear its not just me lol

"Bad fuel" is an overused description that gets through around all the time (typically by a dealer).
Apples to apples fuel (so #2 to #2, not #2 to Bio) you are not going to see a mileage different running empty between any fuel you dump in the tank. Towing at max rating, maybe you could see a mileage difference due to btu's being down if you were at max water before the engine starts to complain but I doubt it in a little 3.0.

Buy from whoever is selling the most and get fresh fuel, don't bother with additives.

Jellyfrosh said:

Anybody else had this happen? I've never noticed anything that dramatic in any other diesel I've ever had and I've had 5 different diesel vehicles. This engine seems extremely sensitive on fuel quality.

Click to expand...

I bet you didn't get the fuel you thought you did. IE, you anticipated #2 and got #1, or bio, or renewable.

There are different qualities of diesel fuel. I talked with a fuel hauler a while back and he said it's similar to how any branded gas station has specific additives they can throw in that cost PENNIES per gallon, yet still allow for accurate testing when in a lab. This allows them to charge your for a gallon of fuel, while only giving you maybe .8 or .9 gallon of fuel. The rest is made up of cheap additives and ethanol (if required for 87 fuel).

His suggestion was to buy from an independent place that turns over fuel on a regular basis. There you get just fuel, not 50 additives blended in. His view was that it's a gimmick and allows the big players to make even more money. I understand that there are additives for necessary things, so I'm not trying to open up a huge debate.

But, that info being said, when you do buy from a supplier that has their own specs, you can get premium fuel. FS is one that farmers use and their DIESELX GOLD is some good stuff. Equipment runs better on it from what I've seen in using it on my stuff.

steiny93 said:

I bet you didn't get the fuel you thought you did. IE, you anticipated #2 and got #1, or bio, or renewable.

Click to expand...

I live in rural Wyoming, I have never once seen a place that sells bio. I'm guessing it was a load of #1 but even running 1# all winter it wasn't that bad.