Getting super low MPG with my 2023 SR5

My SR5 has aprox 700 miles and gets some really awful MPG, no more than 11.6 in the city. The only mods I have done until now are some MRW 707 Method wheels 0 offset, some 265/70R17 AT tires load E and a 3 piece ARB skid plate.

I have seen a few post and replies of other users saying they get aroung 17-18 even while having lift and 285 or bigger tires. I dont really understand why Im getting such a low MPG, I was aware Load E tires would affect mpg but I dont really think this much.
Pd: I use premium gas

 

A) stop using premium gas
b) break in miles are going to be slightly less with mpg
C) are you going off of dash or are you calculating?

 

Don't use premium. You won't gain anything but extra room in your wallet.

Heavy tires kill fuel economy, especially in stop and go traffic. I don't know how you drive, but taking it easy on acceleration can help. Try to keep the RPM's below 2500 RPM's whenever it's practical.

Also, what @Jynarik said!

 

Hi, thanks for answering back so fast! Yes the info i have is from the dash.
Would you recomend using regular gas instead of premium?

 

Yes

 

Hi man! Thanks for the reply,
I usually try to keep the eco light on and drive super chill, I will def switch to regular gas instead and see if it helps

 

As mentioned above, break in mileage tends to be a bit lower than normal, also.

If keeping the eco light on isn't working, try giving it just a bit more gas. It starts making a little more power around 2000 RPM's, and seems to be pretty efficient in that RPM range.

 

My mpg has gone up 2-3 after break in from about 15 to 17/18

 

Hey man, love the color of your rig. How many miles did it took to break it in and see that improvement?

 

About 600

 

Heavier tires, possibly heavier wheels (not sure how the methods compare to your OEM), and heavier skids all equal more weight. The rotational mass increase (tires and possibly wheels) probably do the most damage.

As others have stated:
1. Give it some time to break in. Are you resetting fuel efficiency calculations with every fill up or keeping a running total? Running total will take forever to change
2. There are several argumentative threads about regular vs premium. I run regular and so do many others. Before I added weight I was far outpacing EPA estimated MPG with regular - it's fine
3. I added a lot of weight before a lift and heavier tires and nothing came close to making a difference before those. Not sure if it was the increase in tire size, increase in weight, or less efficient aerodynamics but it dropped MPG by about 3. I also switched from more highway to more city (town really, with lots of lights and a 50 mph speed limit between) driving. These things do not like to accelerate a lot of mass quickly, efficiently. That said, I'm way heavier with larger tires and get about 5 MPG better than what you quoted

Regardless of eco light I'd try to lighten up on the throttle and see what kind of results you get, especially if you are accelerating just to stop again at the next light. 11.6 seems crazy low even with some added weight so my guess is that it comes down to driving style

 

This is super helpful, thank you so much for taking your time to explain in such a clear way. I have been running total fuel efficiency calculations and I have seen an improve from 9 to 11.6 MPG over the past 3 weeks. Next time I fill it up I will try reseting it to have a more accurate calculation! I will def try regular gas from now on. Thank you again man, I really appreaciate it

 

I did get bad mpg. But now at 1100 miles. I get 21 mpg on the highway. Try to coast when it is possible. Also get a break in oil change at 1000 miles. I am satisfied with the mpg of my truck. I am stock with just stock size KO2s. And I keep 38 psi