Improved 5mpg on BFG K02

[borfoo3]

Dunno how you guys get nice mpgs.. been getting 15L/100km (~15.5mpg) on average and noticed less than ~1mpg gain when running +40psi vs my current 33psi..
Got BFG KO2 C rated 265/70/r17 and almost always driving unloaded w/ 1 passenger max.

More importantly, don't know why anyone who mods an offroad bof truck would care on such things unless worried about going outside the grid and risk running out of gas.

 

[cutty01]

How are you calculating your mpg?

How are you all calculating your mpg with tires larger than the stock size? I read that you can no longer rely on the computer display because it is off calibration. Is that not also true if you are just looking at the odometer to get miles traveled and then making the calculation off how many gallons you add back into the tank? I would think the odometer distance would be off too because the larger tires travel a greater distance per revolution.

PS - I am airing my 275/70/17 KO2s to 44 psi and it seems to give me a good combination of ride comfort and road noise.

 

[Runn4est]

How are you all calculating your mpg with tires larger than the stock size? I read that you can no longer rely on the computer display because it is off calibration. Is that not also true if you are just looking at the odometer to get miles traveled and then making the calculation off how many gallons you add back into the tank? I would think the odometer distance would be off too because the larger tires travel a greater distance per revolution.

PS - I am airing my 275/70/17 KO2s to 44 psi and it seems to give me a good combination of ride comfort and road noise.

I wouldn't really rely on the computer's calculation anyway. I have stock size, so I don't actually do this, but you would adjust your miles traveled according to the tire you have. Obviously gas consumed is what it is.

 

[Racehoss]

Tire sound at low speed

I have 265/70/17 on TRD wheels at 41PSI. They are new. At slower speeds, about 10 mph with the windows down, my tires sound kinda like when you peel a sticker off a surface. Very sticky sound. Perfectly aligned. Is that because they are new? about 1500 miles.

 

[Runn4est]

Take it for what it's worth, but I also emailed BFG to see what they had to say about Load C on our 4Runners. They responded with:

"For normal driving you would do 50 front and 50 rear.
Minimum PSI is 20 PSI at speeds less than 15 MPH for off-road use.
Once you go back on road inflate back to 50 PSI.

The max is 50 PSI on the tire and you would need to run at 50 PSI to meet the OE specs."

 

[proimion]

This thread is relevant to my interests so I kept track of the last 2 tanks of gas. I am running KO2 LT265/70R17 Load C on a stock suspension.

For the first tank of gas the tires were at 38 PSI cold which is what Discount Tire set them to on install:

Miles driven: 315
Gallons consumed: 18.1
Average speed: 29.9 MPH
MPG: 17.40

For the second tank of gas, I cranked it up to 45 PSI cold, 5 short of what BFG apparently recommends for these tires on this vehicle:

Miles driven: 361
Gallons consumed: 19.9
Average speed: 25.0
MPG: 18.14

Weather conditions about the same for each. Both tanks consumed completely on pavement in the metro area. Loads about the same for each, 1-3 souls on board, no cargo or trailer, etc. Same non-aggressive driving style.

Despite traveling 4.9 MPH slower, I gained 0.74 MPG with the fuller tires. Perhaps if I did a bit more highway driving, I would gain as much as 1 MPG. But did I get the magical 5 MPG gain? Nope. I will continue to track because I'm just that kind of guy. But based on this small-ish sample size, I'm not expecting any miracles.

 

[RysiuM]

I'm commuting my 2012 SR5 (all stock) for the last 9 months (over 15k miles total) - same driving style (old lady type) with "Eco" light almost always ON. You know this type - the one makes you wishing to have a bazooka in the roof.

Anyway, this driving gave me average 20.5mpg with original stock Duelers inflated to recommended 32psi. Two months ago I installed KO2 265/70R17 C-rated and for the comfort I inflated them to 37psi - at this pressure 4Runner drives like a Cadillac limo.

The average gas mileage dropped now to 20 mpg which was expected (softer tires make more resistance). At the beginning I had them inflated to 45psi (the calculated pressure for the load), but then the ride was not that smooth. At 37psi C-rated KO2 sits well with good shape where it touches the pavement and after 3k miles already they don't look like bad wear.

By the way, I found if I stop driving like an "old lady" and accelerate with engine running between 2k and 3krpm the gas mileage drops to 19mpg and lower. So my personal conclusion is that it is not important what tires you have but how hard you press on these two pedals when you drive.

And of course if anyone is concerned about low mpg of 4Runner, it is to late now. The numbers were clearly stated on the window sticker when you bought it: 17/21mpg (4x4) in EPA test with stock setup, brand new from the factory condition.