Gotta agree with Frank on this one. If you manually calculate your MPG they'll definitely come out differently. I've never gotten more than 14 mpg out of my disco. I regularly sit at 12.5. There was a single solitary tank that came out around 19mpg, but I filled up after about a 30 minute drive and added some gas out of a can which I guessed on the amount left.

 

I routinely get 16.5 on freeway trips at 75mph. I do use the pencil and paper method and start from a full fill up, then top up after about 10 gallons is burned, then its just math.

Once I calculate in city driving no more high teens.

I call my truck the 5000 lb fuel quality detector. I've found that my truck performs better using Chevron Supreme. I Tried the Costco premium but was disappointed in the performance and found it was not worth the savings. I can tell instantly now when using inferior gas.

I use Chevron Supreme exclusively. 92 octane in these parts, with Ethanol. Occasionally I'll find non ethanol premium (in Idaho) which runs even better!!

I previously used ARCO AM/PM premium until my mechanic told me to stop using bad gas. Had some dirty injector issues, etc. I then manned up to the Chevron Supreme and have not looked back. Even the low grade AMPM premium does not run as good or clean as Top Tier Supreme. I suspect AMPM is the same gas or similar to Costco. Bottom line even budget premium is not as good as top tier premium. Both may be better than running regular but low grade is low grade, cheap is cheap, you get what you pay for in this case.

 

Rocking an average 12 mpg after a full rebuild of the truck. I drive about 40 miles everyday. 30 highway 10 city.



Wife gave me permission to start the planning process for an engine swap I'm thinking the 2.7L Ford Ecoboost if I can find I one. Otherwise either the 3.5L Ecoboost or 4.7L. Hoping I can get 15 city and hopefully break 20 for highway. Plus the addition of 100+ HP and torque for towing!

 

X2 on the discount gas. I dipped to around 7.5mpg with a Costco tank once, never again. Truck felt like I was towing the titanic.

 

Run your tank until the light comes on fill up and go from there. Your numbers will be different.

 

I'll stick with 93 octane fuel

 

These numbers are Very reasonable.

 

Why would they? Assuming you don't change your driving habits, your engine needs the same amount of fuel for a given situation whether you have 9/10 or or 1/10 in the tank.

 

I think 16.5 is reasonably achievable under the right conditions with a truck in tip top shape without off road tires, roof rack, large lift, etc. Any more than that and I'd get skeptical, and I disagree that running the tank to empty will change the numbers. It never has for me.

 

Give it a whirl, all I am saying.