Hello, I’ve got a 2021 F150 powerboost. When I first got it, I was getting 21.5 MPG on the highway and 21.5 MPG in town (b/c in town is where the electric mode is beneficial).

I had a 2” leveling kit installed.

I put a bed cover on it.

I put on 285/60R20 tires on it.
It came stock with 275/60R20 tires on it.

I dropped to 16.5 MPG.

Which modification do you guys caused the most change?

 

Are these average MPGs your using for reference? I'd run through a couple of tanks at least to get a good figure to use there. Also are you taking into account the larger tire diameter? That will throw off your mpg reading by 1.5% or so given those sizes.

 

Those are MPG figures that I took from the truck read out. I drove 3k miles before the mods. I have driven 25k+ miles after the mods. I reset the data once I got the mods and since then, it has steadily been at 16.4-16.6.

I have used the Maps app on my phone to confirm the odometer. I took a 200 mile trip and the GPS distance on my iPhone matched the odometer with .1 mile.

 

Have you recalibrated the truck to the new tire size? A GPS should have shown that there is a difference in distance traveled vs odometer reading before and after the taller tire was installed. And I think it's well established here that the MPG readout in the truck can be off by quite a bit. Before i changed mine through the Engineering Mode, it was off by 2mpg on average (reading high).

I have no doubt you lost maybe a couple mpg from the change even if a tonneau could have technically helped out a bit in the process. I'd find a way to recalibrate the truck for the proper tire size (think ForScan can do it), alter the AFE Bias in Engineering Mode and even then always hand calculate every fill up (also helpful to track $$ per mile and other useful metrics).

 

Thank you for your expertise. I will look into the recalibration.

I understand the computer readout can be off, but I figured before and after were relative, so I was more concerned about the change in MPG, rather than the actual MPG.

 

Yeah the relative difference on the readout should be consistent aside from the tire size change, so I'm not entirely sure there other than maybe driving habits changing or something. Not sure what others with the PB are getting after a level and such, but maybe someone will post up what they are getting to give you a baseline.

 

Slightly less aerodynamic.
Added weight with the bed cover (assuming it's not a vinyl rollup cover)
Added weight of the tires, and larger diameter
Bad math due to inaccurate odometer.

I don't see anything wrong with a loss of 5mpg.People see 4-6 with gas jobs, no doubt your electric use is less (unless you've been able to confirm the use of electrical is still very similar).


Each thing is just a slight change. The tires are barely taller. There is very little added weight. There is slightly less aero and the tires probably have a noticeable amount of rolling resistance compare to the soft tires installed by OEM.

 

If those are LT rated tires you are adding probably 15-20lbs additional per corner. That’s a lot of rolling resistance. If you want to preserve stock mpg go with SL rated tires in stock size as close to weight as possible. Stock hanooks run around 41lbs per tire.

 

I leveled mine, kept the same tires, added bed cover I i get about the same as you. It's the level.

 

That’s interesting. I did the same except I went with 275/65/20s (a 34 instead of a 33). Didn’t recalibrate. 5.0 with start/stop disabled. Went from upper 18s to upper 17s and haven’t recalibrated. Surprised your drop was so much