How to get better gas mileage from your Jeep Wrangler TJ

Come over to 'the darkside' ....... you'll never go back.
Having run Caterpillar and Cummins powered logging equipment for 40+ yrs. .... the sound is 'music' to me ....
A lighter weight diesel would be an interesting TJ transplant.
The 4BT Cummins is a heavy little sucker ..... fairly indestructable, and best of all ..... you'll be able to run Rotella T 15W-40 !!
 
Yeah, the 4BT is cheap, easy to come by, and it's the most popular and well documented diesel swap for the TJ. There are lighter options, for sure, but you'd be in a world of self discovery then. The 4BT swaps have been done enough that there are conversions parts readily available for them.
 
So out for a 400 mile drive a few days ago after a snowstorm. Compact and ice everywhere. Hardly any traffic tho. Never went over 50mph. Never used full throttle but stayed in 4WD for the whole drive. BEST gas mileage ever, 22mpg. The only difference from any other day.... low rpms and very light foot on the accelerator.
 
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Not surprised, I have been able to get 20-22 mpg from my TJ on long highway trips (without hills).

It's possible, just not something you should expect other than once in a blue moon.
 
Chris said:
Not surprised, I have been able to get 20-22 mpg from my TJ on long highway trips (without hills).

It's possible, just not something you should expect other than once in a blue moon.
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That perfect day when it's all down hill and the wind is at your back.
 
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billiebob said:
So out for a 400 mile drive a few days ago after a snowstorm. Compact and ice everywhere. Hardly any traffic tho. Never went over 50mph. Never used full throttle but stayed in 4WD for the whole drive. BEST gas mileage ever, 22mpg. The only difference from any other day.... low rpms and very light foot on the accelerator.
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Do you recall what your RPMs were for your trip? The auto tranny would keep it in 3rd or 4th gear (depending on if it's a 32 or 42) while a person driving a stick could keep it in 4th, 5th, or 6th (if they had a 6th gear). I'm just curious.
 
billiebob said:
So out for a 400 mile drive a few days ago after a snowstorm. Compact and ice everywhere. Hardly any traffic tho. Never went over 50mph. Never used full throttle but stayed in 4WD for the whole drive. BEST gas mileage ever, 22mpg. The only difference from any other day.... low rpms and very light foot on the accelerator.
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U.S. gallon / 3.7854 litres .... or .... Imperial gallon / 4.456 litres ?
 
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I get about 18 miles per gallon when I mainly stay on the highway. That's in 5th gear, at 1,800rpm the whole time, 33" tires and 3.73 gears.
 
Head Lice said:
Come over to 'the darkside' ....... you'll never go back.
Having run Caterpillar and Cummins powered logging equipment for 40+ yrs. .... the sound is 'music' to me ....
A lighter weight diesel would be an interesting TJ transplant.
The 4BT Cummins is a heavy little sucker ..... fairly indestructable, and best of all ..... you'll be able to run Rotella T 15W-40 !!
Click to expand...

The purr of an idling diesel sounds amazing. Sounds WAYYY better than any gasoline engine.
 
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UpperMI said:
Do you recall what your RPMs were for your trip? The auto tranny would keep it in 3rd or 4th gear (depending on if it's a 32 or 42) while a person driving a stick could keep it in 4th, 5th, or 6th (if they had a 6th gear). I'm just curious.
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Mostly 5th, 6th on the long straights... which are few in BC.
 
TimB54 said:
I have a 2.5L and whoever suggested shifting at 3000 rpm, thank you. It drives much better and, to my surprise, fuel economy is better. Averaging about 16.5 mpg around town. Eat your heart out Prius :)
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I been driving it more at 3000 rpms lately mainly due to the hills I have on my new commute to my gf's house and the bucking issue at 2000 rpms. My latest calculations come to 19.3 mpg and that is pretty impressive considering the exhaust manifold and gas tank are leaking. This is also with my doors off full time.
 
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I logged an all time high with mine a couple weeks ago. Traveling from my folks cottage, on two lane highway, cruise set at 65. 18.5 mph. I thought that was pretty good for a 13 year old vehicle with 130,000 miles on the clock.
 
There are always these options.... lol (Not surprised that both of these are JKs haha)
streamlined jeep.jpg
Aero-Jeep.jpg
 
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Ranger_b0b said:
I logged an all time high with mine a couple weeks ago. Traveling from my folks cottage, on two lane highway, cruise set at 65. 18.5 mph. I thought that was pretty good for a 13 year old vehicle with 130,000 miles on the clock.
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Another Prius killer! Way to go! I got a hair under 20 mpg on a camping trip to Republic WA last summer, but haven't taken a long enough highway trip since to know what the current highway mileage is. As a lot of folks have said, if you're look for good gas mileage, you bought the wrong car.
 
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