Are these lowering my gas mileage?

We know the lift doesn't matter, the tires do.

But for the record I do have a topper and at the time had 3 passengers and 300ish pounds of camping gear in the truck.

 

Its most likely your driving habits. So Cal speed limit will always get you. I drive daily from Costa Mesa to San Clemente and I know how difficult it is to keep it 65mph. Ive noticed a huge difference driving conservatively. Im running 285/70/17 Nitto Terra Grapplers but am managing to get around 19mpg.

 

It definitely will. Especially because you already have a good set of tires. The Tacoma a good upgrade to the Silverado? I actually like GMs. I own two of them, but really like my Tacoma as well

 

i do feel the silverado was more comfortable seat wise. Maybe it was a little smoother of a ride also. But, the tacoma is way more fun to drive. just as powerful feeling. and i dont know but the tacoma just seems to fit very well. There is just something about the tacoma that doesnt have a "manufactured" feel to it as the silverado did. tacoma feels like its made for me

 

Picked mine up a few months back and I was told to expect 17-21. Wish that were the case, I can be pretty heavy on the petal and I average about 13 MPG as well. Typically on a full tank I average just about 300 Miles.

 

i have 285x18's on an 18*9 wheel and 2000 miles in 10 days averaged 18mpg most hwy driving was 75mph +, I was a bit surprised but in doing the math was happy

 

Anything other than the stock-sized wheels and tires will decrease your gas mileage period. Those Japanese engineers are paid a lot of money to figure this stuff out....

 

I have the same setup as you with a leer shell, 6 foot box, and 265 70 17 KO2s E and I'm right around 19 mpg/20 mpg depending on how much city driving I do. Plus we have pretty big hills here in our city to go up so that doesn't help.

 

Also keeping in mind that changing the size of your tires also throws off your Speedo/Odometer. Therefore, the miles it says you drove aren't actually accurate.

For example, my 2015 SR5 4x4 DCLB. I calculated that my 255/85/16 ST MAXX threw my Speedo/Odo readings off by 9% compared to the factory tire size. So when the math shows I got 14MPG I actually got 15.26MPG.

This also means you need to change your oil more frequently than the trip meter shows since the trip meter is also off by 9% (and the oil maintenance light).

 

I average 14 with 285's

 

My speedometer has been corrected, was from the day the lift wheels and tires went on. My sheriff buddy has confirmed both by radar and pacing me.

 

With stock wheels/tires my speedo is off about 3% according to my GPS. 70 mph on the speedo shows roughly 68 mph on the Garmin....I wonder if Toyota sets it up this way to protect us from ourselves.

 

You could fill the tires and cap with helium.

 

I'm getting 13.5mpg with lift front rear bumpers shell 33" DCLB

 

Bro lean = -5 MPG. Get that nose down.

 

haha your right on the bro lean. If anything ill lift the rear end to match, otherwise i would rather have the lift i have than put it down to stock

 

The under carriage is defiantly not aerodynamic. Never got why you would level your truck, after 200lb your truck in now doing a bro lean and looks really bad. lift 2.5 front lift 2.5 back. That's just me tho. I get 18.5~19 unloaded, pulling what I haul(6k to 9k) 12~14 at best. Running stock size ATm's with no lift.

 

actually my truck looks damn good

 

well guys my gas light turned on yesterday at 275 miles. I drove it until 302 miles and topped off the tank. If i assume the dealer topped off the tank that i just ran through, that would mean im getting around 14-14.5 mpg. Not bad considering i drove it pretty hard. We will see what this next tank gets me driving more conservatively.

 

It's crazy we have all this technology in our cars but the analog fuel gauge is still as inaccurate as ever. I usually have to drive 70 miles or so to get the damn need off the the "F" pin.