Absolutely awful mileage
03-23-2016, 12:15 PM
#31
Senior Member
Do you really need to ask the dealer? A bigger circle travels farther in one revolution than a smaller circle. So, if your new tires are 20% bigger (made up number) than your old tires, and your truck says you're going 60, then in fact you're going 72.
03-23-2016, 12:16 PM
#33
03-23-2016, 12:27 PM
#35
Senior Member
22.5 in the city with a 3.5EB? Damn we live in different cities for sure. I'm 15.0mpg with 80/20 city/highway driving. Traffic lights and long intersections crush my MPGs. Highway is so variable. In "ideal" conditions I can get 21-22 but if there's a poof of wind it drops to 17.
03-23-2016, 12:37 PM
#37
Senior Member
I've had 4 ecoboost all with the same size tire 285/65/20 (with BFG ko and ko2) you're adding between 20-25 lbs of rotating weight per corner when you switch to those tires plus on a level you will slightly mess up aerodynamics.
That alone will drop your mileage 1-3mpg depending on how you drive, what configuration the trucks is, winter fuel etc. It just happens.
Add on that your speedo is off anywhere from 5-7% and your real mileage at an indicated 15 mpg is really close to 16. While not much better that is really what you are probably getting.
Just part of the deal, you cant have your cake and eat it too. But considering you have the newest truck with 420ft-lb of very usable torque and nearly a 35" tire and getting roughly 16mpg I would say that's not bad but that's just my .02
That alone will drop your mileage 1-3mpg depending on how you drive, what configuration the trucks is, winter fuel etc. It just happens.
Add on that your speedo is off anywhere from 5-7% and your real mileage at an indicated 15 mpg is really close to 16. While not much better that is really what you are probably getting.
Just part of the deal, you cant have your cake and eat it too. But considering you have the newest truck with 420ft-lb of very usable torque and nearly a 35" tire and getting roughly 16mpg I would say that's not bad but that's just my .02
03-23-2016, 12:41 PM
#38
I have a 2.5AS level and 305/70R18 STT Pro's, when my speedo read 69 my GPS would show 75 and I was averaging just under 14mpg all around. I'm running 5* tunes and SCT finally put out the update for the X4 to recalibrate the speedo for larger tires. Once I got speedo calibrated, average MPG's went to about 15. Still sucks, but about what I would expect from this setup.
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MGM (03-24-2016)