How Many Smiles Per Gallon: 265/75r16?

I’m getting 17mpg with 265/75r16 falken wildpeaks on 16x7 SCS ray 10 wheels driving 70mph or less, and no revving higher than 3k. But I also have a GFC camper on the back and some gear that lives in there. If i get on the gas it drops significantly to around 13.5mpg sometimes as low as 12.5mpg. The magnuson supercharger doesn’t help with mpg unless im taking it easy on the throttle.

 

I'm a poor one to compare to...since I learned to drive in Houston, TX and always keep my foot on the gas...but I seem to average 16-18mpg, which is less than I expected.

 

Swapped my stock SR5 tires (245/75/16) on stock alloys for passenger rated 265/75/16 Cooper Adventurers on stock 2nd Gen steelies at about 2000 miles. I was averaging a tick over 19mpg according to the dash before, now I'm averaging 18.5mpg according to the dash. Speedo read about 3% high before, now it's spot on so I definitely lost less than 1mpg. When I'm on the highway in the morning I'm doing 75+ most of the time and I'm still getting passed.

 

I’m not 100% certain, but my guess is that odometer, mph, and mpg were all impacted by the slight change in size. I think it’s ~3% or so. I upsized to toyo 265/75/16 and did the speedo recalibrate just to make sure I was as accurate as possible. Fwiw, I may have lost 1mpg. Nah… I just checked my fuelly records and I’m pretty stable.

For your question, I don’t know. The taco is definitely going to be mechanically a little off. The only way for a comparative answer is highway miles with the mile markers for reference.

 

Getting between 17.5 to 19 in town on 285/70/17s Toyo AT3s SL rated, lifted 3/1 on Bilsteins. Been on the latest KDMAX Pro 9 tune by far the best. Gas mileage and tune were done the same day so its about the same when I was on 265s with the Pro tune. This is checking it old school vs now with the inline calibration which is accurate. No extra weight except a bed mat and oem bed cover.

 

18 pro 265 75 16 duratrac...18mpg

 

What Octane are you using?

 

Eh, I’m not one of the cool kids I guess. I downsized my 265/70/17s to 265/65/17s for better (back to stock) acceleration. Don’t really care about looks but honestly the looks are good anyways.

my mpg has always been about 15 lifetime average on both tire sets and that will likely never change. It might go down further when I regear.

 

I upgraded from the OEM Goodyears to size 265/75/R16 on the OEM wheels in December 2019. I got about 40K out of the OEM tires, and closing in on 50K on the 32" tires (currently on 2nd set of those). I have used Fuelly app to keep track of my MPG since long before I bought this truck, and switching tire sizes made zero difference in my mileage stats. Biggest factor for me has been long run at constant speed vs short local runs with lots of speed variations and start/stops. Which is typical for every vehicle and driver, for the most part.

 

Didn't notice much of a hit when I upsized, and not much more of a hit after the 2/1" lift, but I dont do much Highway driving, and I dont look at the computer, I just gauge by how I drive weekly.

Mind you after one 6 hour Highway drive, I didn't notice much difference either, (from previous drives before the lift).

I do however notice a hit in the winter....

 

They should have just kept the 4.0

 

New truck inbound and considering similar. Subb'd for future responses.

 

Your mileage tanked because of the difference between the stock highway tires and the heavier AT tires you installed.

 

I have the '22 TRD Sport also, access cab-manual, and threw on some new wheels and T/A KO2 (58 lbs vs 36 lb toyo) sneakers for winter use and I went from 19 to 15.

Edit:

I also have all my tools for work in the bed, winter workwear and tools in the access cab and I went with a Pedal Commander set at sport +3 which makes it a completely different truck, a joy to drive.

 

285/70r17 km3's c4 front bumper winch pinsu roof rack rci bed rack sso rock sliders 3 inch lift 4.88 gears needs 5.29's and i'm averaging 15-16 hand calculated but i'm also driving normal. And majority is highway.

 

Wait youre on 285s with 4.88. And you think it needs 5.29? Care to elaborate? Im considering going up to 4.88 and ive got a similar build out weight wise to you

 

I'm only going to be getting heavier when buy full skids rear bumper and pack it full. I've been i a buddy of mines with close to the same setup and it shifts and feels better pulls better up hills.

 

Here is a video from Nitro gear talking about re-gearing their stock truck to 4.88. It is their opinion that 4.88 is closer to what the stock gear ration should have been from the factory.

https://www.youtube.com/watch?v=XxBWZGQIScI&t=123s


So if you believe that the factory gear ratio should have been 4.88 and tires at stock 30.6 inches, then upgrading the tires to 285/70r17 (32.7) mean the new gear ratio to keep the same performance would be 5.29(32.7x4.88/30.6=5.21)


On top of that the cost of installing the gears is high, but the same for 4.88 and 5.29, so you might as well go 5.29.

 

What’s your top speed with 5.29 gears and 33” tires?
I’m still trying to be able to keep up with traffic, I don’t like being stuck in the slow lane. That’s why I have a supercharger.
If I do re gear, it’s 4.88, and if I do go larger tire I’d only go as big as 285/75r16s.

 

Fascinating. I've never considered a re-gear due to the cost involved. I also tend to keep my vehicles close to stock. I have a 2023 TRD OR coming in next month and now considering looking into re-gear options. I'll post questions in a thread that's actually related to re-gear.