Understated MPG with 33" wheels?

A lot of variables.
Elevation
Driving style
Fuel quality summer-winter blend
Vehicle weight (mods)
Tire type/weight/width
Ambient air temp
Tuned, not tuned
And on and on.

Me I’m on 285/70/17 AT tires
I getting @17 mpg city
and over 20 mpg on the highway.
I plan on going to skinny tires
next time around.

 

Stock Gearing? Looks like I need to look into KDMAX tune as mentioned on your profile. I need more mpgs ha.

 

stock gears. The KDMAX tune is awesome!

 

I don't know if you were referring to my post, but I have a Sport not an OR and it came with 17" wheels, so for me, 265/65/17 was stock.

 

Consider wind speed and direction also.

 

No, it was for OP. He has an OR and has the wrong stock tire size in his calculator.

 

Don't forget about the coriolis effect

 

Spin drift will have more effect

 

Not to mention that coriolis would only have an effect if the truck was floating

 

I'm running 285/70/R16 on Methods on my TRD OR. Hard to say the exact change considering I have an LT kit up front and kings in the rear. I average 13.6 MPG and my MPH is off 4-5 MPH. Hopefully, this helps!

 

2018 auto w/33” tires 5.29 gears and custom tune, steel bumpers

My average on the interstate with cruise set @65 (my Speedo is off, so math guys do your job) but set at that I get 16ish mpg. Anything over 65 (by my dash, not the really mph nerds) anything over I drop mpg like I’m pouring out the window, I mean like 12-13ish range. And that’s without a trailer. I do live in Ga, near Atlanta so it’s hilly. When I lived in La (Louisiana) with the same set up I was getting 17ish close to 18 on the interstate. City roads, obviously the stopping and going it crashes down to 13-14mpg.