Dramatic MPG Drop
Thread Starter
JK Newbie
Joined: Dec 2011
Posts: 92
Likes: 0
From: Charleston, WV
Originally Posted by jeepmojo
im saying theres nothing you can realy do besides put your stock tires back on if you dont like the drop in fuel ! i feel the drop is part of the game if you want it to look good ! if your looking for fuel consumption vehicle put the stock wheels back on and sell the 33s
you have those 2 choices and nothing more ! (just advising with the only knoledge ive found to be true ) dont lift it or it will get worse due to wind catch ! concider it a harley if you want bad ass look you loose the manufactures specs and design and fuel specs but if you want to drive around stock and can do that , then more fuel mpg can be had!
id choose the drop in fuel to look the way i want it ! and just not go as far ! lol
but dont worry , if things go as planned all of us will be parked in driveways all over the country @ $ 5.00 gas or more !
you have those 2 choices and nothing more ! (just advising with the only knoledge ive found to be true ) dont lift it or it will get worse due to wind catch ! concider it a harley if you want bad ass look you loose the manufactures specs and design and fuel specs but if you want to drive around stock and can do that , then more fuel mpg can be had!
id choose the drop in fuel to look the way i want it ! and just not go as far ! lol
but dont worry , if things go as planned all of us will be parked in driveways all over the country @ $ 5.00 gas or more !
JK Super Freak
Joined: Jun 2011
Posts: 1,715
Likes: 11
From: Olympia, WA
Lots of talk here about fuel consumption and what causes more of it.
Yesterday I had the stock SRAs aired down for comfort on the trail. Didn't want to hold up the rest of the party when airing back up, so only put around 31 PSI back in the tires.
Usually when I hit the pavement at 35 PSI and reset the MPG I see at least 23-34 MPG running a steady 60 MPH. At 31 PSI the computer only showed 21 MPG. Just one more thing that says tires have a BIG effect on fuel consumption.
(I've heard the misgivings about the MPG computer, but I've tested it against manual calculation over and over and totally believe it to be accurate when its is used and interpreted right. In fact, unless the Jeep is perfectly level and refilled at the same gas pump, the computer is more accurate than manual calculation.)
Yesterday I had the stock SRAs aired down for comfort on the trail. Didn't want to hold up the rest of the party when airing back up, so only put around 31 PSI back in the tires.
Usually when I hit the pavement at 35 PSI and reset the MPG I see at least 23-34 MPG running a steady 60 MPH. At 31 PSI the computer only showed 21 MPG. Just one more thing that says tires have a BIG effect on fuel consumption.
(I've heard the misgivings about the MPG computer, but I've tested it against manual calculation over and over and totally believe it to be accurate when its is used and interpreted right. In fact, unless the Jeep is perfectly level and refilled at the same gas pump, the computer is more accurate than manual calculation.)
JK Enthusiast
Joined: Mar 2011
Posts: 119
Likes: 0
From: Zimmerman, MN
I switched out my stock 255/75/17's for a set of Maxxis Bighorn 285/70/17's. Since doing this about two weeks ago I have seen a nearly 2 1/2 mpg loss. That's a huge loss for such a little change, and I definitely didn't expect a drop like that. Any else experiencing the same thing?
All hand calculated and the speedo was corrected with procal and tested with GPS its right on.
Last edited by Basecamper; Jan 30, 2012 at 05:16 PM.
JK Enthusiast
Joined: Sep 2011
Posts: 440
Likes: 1
From: Columbus, OH
Thread Starter
JK Newbie
Joined: Dec 2011
Posts: 92
Likes: 0
From: Charleston, WV
Originally Posted by Basecamper
Short answer is yes I expereinced the same 2 1/2 mpg drop when I went from 285/75R16's. My tire and wheel combo was 6 lbs heavier per corner and like you I was surprised I expected 1 mpg or so but not this.
All hand calculated and the speedo was corrected with procal and tested with GPS its right on.