How to get better gas mileage from your Jeep Wrangler TJ

801 Driver said:
Newbie here, 98TJ 4.0, 5 Speed, got a "shift light" on the dash. Not like my old hot rod Chevy tack at 6800RPM. This thing seems to want me to always "lug" the engine, 13-1500 rpm. I kinda ignore it like a faulty Ck engine light. Stock everything, but are the 4.0's supposed to be lugged all the time at 1100-1500RPM? Does not sound right to me. Thanks
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Don't trust the shift light. It's always early. I find that my best/smoothest shifting is around 3,000 rpm and I try to cruise at 2,500 - 2,700 rpm.
 
Rob5589 said:
I have never even bothered to check with mine. 5 or 25 mpg, it won't change anything.
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For my DD Sport, I kept all the gas receipts for over 5 months, waiting for a year, and then I will look at them total cost just for a spit and a giggle..
But then I moved to Iowa and used my little renegade... 31 mpg if I drive like a sissy.

Downside is @ 3000 RPM the booster growls like a boss and it takes off like a mutha-fuka... mpg is down to 19 ave.
 
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Chris said:
Okay, admittedly this title is clickbait, that's sort of what I intended it to be.

However, I'd also like to address this issue because I see the question come up quite frequently, "How can I get better gas mileage from my Jeep Wrangler TJ?".

There's a short answer and a long answer. Let's start with the short answer:

The short answer is that you really can't get better gas mileage from your TJ.

The long answer is that it may indeed be possible to squeeze a few extra mpgs from your TJ, but it's going to be a big waste of money that you'll spend chasing dismal gains.

The TJ weighs a lot. In addition to that, it's probably one of the lease aerodynamic vehicles ever produced. Think of driving a barn down the highway on wheels. The air doesn't go over the top of it, it runs right into it like a huge air brake. So there's your first issue, poor aerodynamics. In addition to that, the immense weight of the TJ is another issue with poor gas mileage.

Look at a vehicle like the Prius. Aside from the fact that it's a hybrid, one of the reasons it gets such good gas mileage is because of it's light weight and it's extremely aerodynamic shape (believe it or not, a Prius has better aerodynamics than a Porsche 911). The TJ has none of these going for it.

Wasting your money on air intakes, exhausts, etc., with the hope of improving your fuel economy is a royal waste of money.

The bottom line is this: If you bought your TJ with the idea that you could get decent fuel economy from it, you bought the wrong car. Plain and simple.

My suggestion? Buy a second vehicle like most of us have. That way you can have a TJ that's fun to drive, and another vehicle that gets good gas mileage and is great for commuting.
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Chris, I know this is all that I'm still going to, anyways. There's a guy on YouTube, and granted I think he is the only one, but he was saying he was getting three to five miles a gallon more by changing his thermostat from a low temp to hire temp from something like 170 to 195 ish around that ballpark. I know my Jeep runs around that area as well. Are are Jeep supposed to be running that hot around 195 -215 like he said?
 
MsLarr said:
Chris, I know this is all that I'm still going to, anyways. There's a guy on YouTube, and granted I think he is the only one, but he was saying he was getting three to five miles a gallon more by changing his thermostat from a low temp to hire temp from something like 170 to 195 ish around that ballpark. I know my Jeep runs around that area as well. Are are Jeep supposed to be running that hot around 195 -215 like he said?
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He's talking about if you had a lower temp thermostat installed from a previous owner or something. If that's the case, then yes, installing the factory thermostat would improve your MPG, since that low temp thermostat isn't good for your engine. The 4.0 in our Jeeps is designed to run around 220 degrees (sometimes even a bit higher) and will return the best fuel economy (if you can even call it that) running at that temperature.

There are foolish people out there who swap in lower temp thermostats, thinking it's going to improve engine performance, when in reality it does the exact opposite.

It sounds to me like this guy was replacing a low temp thermostat with the correct factory temp thermostat, hence why he saw the MPG increase.
 
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Had a chuckle today.
My first Jeep a few months ago, stock 98 TJ. 4.0 5 Speed, soft top.

Mileage expectations = Not really thought about it, I drive, fill up when the tank is empty.
Reality, after looking back, 18.3 in my first 2K miles, driving like I do, not holding up traffic, but slower than other vehicles I have owned. Keep in mind, all stock, no lift, stock tires, etc

Noise level is the big thing, I tend to keep slower than my normal to hear my radio at highway speed, music and ham radio. I was on a rough back county road to my house today, turned up the music radio. "I can't drive 55" was belting out. Ha Ha. I have lived that life, not my favorite then, but at 45 I had a smile driving my Jeep.

My other driver is a Suburban, gets 17. In town, and on the road, 17. Unless I can keep it between 95 and 105 for a while, there it will get 19-20. Yep, have had that happen several times not fluke.

Use some common sense here.
Buy a Jeep for Gas milage = not going to happen.
Buy a Jeep for a Quiet vehicle = not going to happen
Buy an Airplane for low expense travel = not going to happen.
Marry a hooker while not expecting complications = not going to happen.

I love my first Jeep, should have gotten one much sooner. Yes, I can drive 55 with a smile on my face now in my Jeep.
 
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Probably the best thing you can do to improve mileage on a TJ is have the right gearing!
 
Better MPG Jeep Wrangler.
I think we need to redefine the word "Better MPG".
When do we say when it's better.... 15+ MPG? 17+ MPG? 19+ MPG? 21+ MPG?

My auto trans gets 16 mpg ave. and my manual gets 18 mpg ave. both OEM with 4.0L.

If I slow down in the highway like 55 mph I gain about 1.5 mpg
 
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I found towing my jeep is the best way to increases its mpg. I get 13mpg highway in the tj and 15mpg towing it behind the truck :p

But it gets endless smiles per gallon.
 
Mine, 4.0 auto. Around 3000rpm cruise to get 60mph, but most times going on 2500rpm and i dont care speed; (truck speed most of the times) I can get about 20-22 mpg on 35s cooper stt pro, on trepador 35s about 18mpg.

On trail, never above 10-12 mpg. :cool: On road to get 50mpg i have diesel cars, 75% of them are diesel here in spain. Weekend on trail, "drove her like you stole her".
 
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Actually there is a fascinating podcast at a place called" radical personal finance" where the author Joshue Sheats gives us a nice excel calculator to help decided when it is a good idea to upgrade your vehicle to a more fuel efficient model. The answer? If you consider all costs and the real savings it can still take many years to break even. Episode 386. Took the fun out of complaining about the gas mileage i get. Took the TJ to the car wash and changed the oil after listening.
 
I agree with the folks so said the biggest improvement is to change your driving style. If you have ever driven a car with an instantaneous mpg gauge, you know what a difference it makes.

I used to commute in a 2002 Corvette Z06. If I turned off the mpg readout and just drove like I normally do, I got a consistent 20 ~ 21 average mpg. For fun I thought I would see how high I could get the average up to. The highest number I reached was 25.5 mpg. That's a 25% increase by just changing my driving style, no other modifications were done and I drove the same route every day.

To do that, I drove "like there was an eggshell under my foot". Very gentle acceleration, shifting early, and coasting whenever possible. It was a pain in the ass and not the way I would want to drive all the time. But it was interesting to see what type of driving returned the best mpg.

The other thing that made the most noticeable difference? Shutting the engine off at stop lights! When you sit at a light for a minute or two with the engine running, I could just see the average mpg numbers tick down - 25.2, 25.1, 25.0, 24.9, etc. It's understandable why so many cars today have that auto-shutoff feature, it really does make a difference.

Four years ago I sold the Corvette for a new commuter car - a Chevy Volt. The "lifetime MPG" displays "250 mpg" because that as high as the display goes. I so rarely use the on-board generator that I go months before I buy gas for it. I'm fortunate that I can afford a Jeep and a Volt - fun and practicality. I remember in the '70s when I had a CJ5 as my only car I didn't even want to look at mpg.
 
My commuter is a 2018 Chevy Volt, leased it for 3years, with rebates it ends up costing me about $98 per month. I travel about 60 miles round trip each day and I can charge at work. I've owned it since March and have filled it up once. On the weekends it's all bout the Jeep, errands on Saturdays, Church on Sunday! I give her a drink when she says she's thirsty and do not care about the MPG. My other fun car I drive occasionally is a chipped V10 twin turbo Diesel 2007 VW Touareg, it is a beast and get's 18mpg no matter what. I did find my driving habits change when I'm in the Volt as I try to make it to home and back on 1 charge, but once in awhile you have to display how quick the volt can be!
 
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Cudabnu said:
My commuter is a 2018 Chevy Volt, leased it for 3years, with rebates it ends up costing me about $98 per month. I travel about 60 miles round trip each day and I can charge at work. I've owned it since March and have filled it up once. On the weekends it's all bout the Jeep, errands on Saturdays, Church on Sunday! I give her a drink when she says she's thirsty and do not care about the MPG. My other fun car I drive occasionally is a chipped V10 twin turbo Diesel 2007 VW Touareg, it is a beast and get's 18mpg no matter what. I did find my driving habits change when I'm in the Volt as I try to make it to home and back on 1 charge, but once in awhile you have to display how quick the volt can be!
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I wish I could switch to an electric vehicle for a daily, but nothing on the market would be able to access my sites.

Here’s hoping the electric wranglers of the future are actually viable.
 
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BoldlyGoing said:
I wish I could switch to an electric vehicle for a daily, but nothing on the market would be able to access my sites.

Here’s hoping the electric wranglers of the future are actually viable.
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Yeah, I've wished for a Wrangler with the Volt powertrain for a long time. Torquey electric motor for trails, and an onboard generator for long distances.
 
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derekmac said:
Imperial or US mpg's?

On my 05 6spd, 4.10 gearing, 35's, I get around 12-13 mpg (US).
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Sounds about right where I am at. I did put a 160 thermostat in it Summer of 2017 and replaced my water pump. I'm going to change that this week. Being in Arizona at the time, simply driving a few miles to the store and home a was too much with the stock 195 thermostat. My radiator would be boiling. With the 160 thermostat it did much better. California is hot as well, but, there's something special about Arizona's heat. It'll heatstroke the toughest in a hurry. Being in California now, my Jeep runs a few degrees cooler, around 190/195. Yet, In AZ, around 210/215. (That is with the 160 thermostat in.)
I'm going to change it regardless and see what happens. Ty for responding. Larr
 
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