MPG's

Joined
Apr 12, 2017
Messages
43
Location
Marion, IA, United States
Is 14.5 MPG normal on a 4.0l auto tj?
Kind of what I expected but one of my friends is getting 17.5 mixed highway city driving. I never go over 60. Ideas on how to improve. Still loving the jeep life.
 
Yes, that's completely normal.

Depending on a variety of factors such as wheel / tire size, altitude, lift, terrain (i.e. flat or hills) and the way you drive it, you can probably expect anywhere from 12 mpg to 18 mpg with mixed city / highway driving.

On long highway only trips with mostly flat terrain, I have managed to get 21 mpg. That's pretty astonishing though, and I would never count on it.
 
If you have oversized tires your mileage may actually be higher than what you are calculating if your speedometer gear hasn't been changed out to match the larger tires. Or if you changed axle gears in your rig.
 
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Is 14.5 MPG normal on a 4.0l auto tj?
Kind of what I expected but one of my friends is getting 17.5 mixed highway city driving. I never go over 60. Ideas on how to improve. Still loving the jeep life.
I wish my TJ got even 13 mpg. Our Wranglers are heavy (they may look light but they're not), have the aerodynamics of a brick, and have an engine design right out of the 60's. It's never going to get good mpg to compete with smaller lighter cars with more modern engine designs.

The good thing is that none of us bought our Jeeps for their mpg. :)
 
Is 14.5 MPG normal on a 4.0l auto tj?
Kind of what I expected but one of my friends is getting 17.5 mixed highway city driving. I never go over 60. Ideas on how to improve. Still loving the jeep life.
I get around 15 locally with my 5 speed but if you are not getting much highway miles that will keep your MPG down. even though the TJ's are a brick in the wind, still get better mileage on highway vs stop and go local traffic. highway I get about 18-19 driving at 55.
 
I wish my TJ got even 13 mpg. Our Wranglers are heavy (they may look light but they're not), have the aerodynamics of a brick, and have an engine design right out of the 60's. It's never going to get good mpg to compete with smaller lighter cars with more modern engine designs.

The good thing is that none of us bought our Jeeps for their mpg. :)
in theory true but my 2014 4 cyl Buick Verano gets worse local mileage than my jeep and according to dealer, my 13ish MPG is within margin of error. burns me up, there is a modern car, 4 cyl, much lighter and gets worse milage than a 13 year old brick LOL
 
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in theory true but my 2014 4 cyl Buick Verano gets worse local mileage than my jeep and according to dealer, my 13ish MPG is within margin of error. burns me up, there is a modern car, 4 cyl, much lighter and gets worse milage than a 13 year old brick LOL
Wow 13 mpg is pretty bad for that car & engine. You sure the O2 sensor is working ok? A bad O2 sensor won't always illuminate the Check Engine light.
 
Yes, that's completely normal.

Depending on a variety of factors such as wheel / tire size, altitude, lift, terrain (i.e. flat or hills) and the way you drive it, you can probably expect anywhere from 12 mpg to 18 mpg with mixed city / highway driving.

On long highway only trips with mostly flat terrain, I have managed to get 21 mpg. That's pretty astonishing though, and I would never count on it.
 
I wish my TJ got even 13 mpg. Our Wranglers are heavy (they may look light but they're not), have the aerodynamics of a brick, and have an engine design right out of the 60's. It's never going to get good mpg to compete with smaller lighter cars with more modern engine designs.

The good thing is that none of us bought our Jeeps for their mpg. :)
I sure didn't buy it for the mpgs. Haha
 
Wow 13 mpg is pretty bad for that car & engine. You sure the O2 sensor is working ok? A bad O2 sensor won't always illuminate the Check Engine light.
Not sure Jerry. Only has 6k miles on it. I can get about 15 mpg with summer gas. They use winter blends in pa and all my vehicles get worse mpg in winter. If o2 sensor was bad wouldn't it affect my highway mpg too?
 
Not sure Jerry. Only has 6k miles on it. I can get about 15 mpg with summer gas. They use winter blends in pa and all my vehicles get worse mpg in winter. If o2 sensor was bad wouldn't it affect my highway mpg too?
You first complained above about only getting 14 mpg. Then you just said you can get "about 15 mpg" with summer gas. Aren't both of those indicators of the bad mpg you first complained about? I suggested above that low mpg can be caused by a bad O2 sensor. I can only make the occasional suggestion, no guarantees.

If 14-15 mpg is indeed normal for your car, no need to do anything. If it's not and you're unhappy with it as I thought you were, consider replacing the upstream O2 sensor. :)
 
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I wish my TJ got even 13 mpg. Our Wranglers are heavy (they may look light but they're not), have the aerodynamics of a brick, and have an engine design right out of the 60's. It's never going to get good mpg to compete with smaller lighter cars with more modern engine designs.

The good thing is that none of us bought our Jeeps for their mpg. :)

Yep. Vehicles that put a smile on your face = bad gas mileage and empty wallets.
 
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You first complained above about only getting 14 mpg. Then you just said you can get "about 15 mpg" with summer gas. Aren't both of those indicators of the bad mpg you first complained about? I suggested above that low mpg can be caused by a bad O2 sensor. I can only make the occasional suggestion, no guarantees.

If 14-15 mpg is indeed normal for your car, no need to do anything. If it's not and you're unhappy with it as I thought you were, consider replacing the upstream O2 sensor. :)
It's not close to what Buick says I should get but dealer feels it's normal. I'm not really concerned about it as I only drive it about 1.5k miles per year. It's not killing my wallet gas wise. Was more a comment that I get better local mpg from the jeep.
 
I get mid to high 13mpg with 4.0, 5 speed , 35,s and 4.88,s. That's as good as it gets. Trying to get good mpg from a Jeep is like trying light a campfire that's not hot. Keep it light, run the smallest tires that are acceptable, proper gearing, and keep it tuned up, and you,ve done all you can.
 
If you have larger than stock tires, do a test one day over distance using GPS on your phone and your odometer. You'll see that you are going father than your odometer tells you (unless you've changed the speedo). That means you are getting better gas mileage than you think. I thought mine was around 13 but really it's around 14. It's all about the same for a TJ. I sometimes wonder if people who say they are getting 18mpg aren't running downhill with a tailwind and being towed with the engine running. Sounds too good to be true. Maybe stock would get 15-16, hard to imagine more...