Jeep Wrangler Gas Mileage Improvement Project

If you’re driving a Jeep Wrangler, you’re always paying at the pump. Forget about ever getting great gas mileage. You can only hope to get slightly higher fuel-efficiency.

There are two big things that work against the Wrangler’s gas mileage.

When you’re going slow in city traffic, stop-and-go, it’s the weight.

When you’re on the highway, it’s the height. It’s all about aerodynamics.

There’s not much you can do about the weight, nor the height, when it comes to increasing MPGs.

The Jeep Wrangler is probably one of the least aerodynamic vehicles on the road today. Driving a Wrangler on the highway is like driving with a 4×8 foot sheet of plywood facing sideways into the wind.

If you bought your Jeep to wheel it – and that’s probably the best reason to buy a Jeep Wrangler – you may be tempted to put it even higher up in the air.

But that’s going to work against you, every time you go to the gas pump.

You can look at using different gear ratios – there’s stuff you can fiddle with – but you’re never going to turn it into something that gets thirty miles per gallon.*

You can squeak a few more miles per gallon out of it. More than anything else, you need to learn how to light foot it.

Here’s a good way to think about it …

The more time your right foot spends on the throttle, the more pressure, the faster you’re going to go through the gasoline in your tank.

It’s that simple.

If you have a newer Jeep, you might already have an average fuel economy gauge. That’s a good start.

If you’re driving an older Jeep, you’ve got nothing.

Thankfully, adding a gauge is a simple task. We mounted a ScanGaugeII between our 1998 Jeep TJ’s steering column and dashboard, using a method we used to call the jock mount – nothing fancy – just a little bit of velcro is holding the ScanGauge in place. The cable is wrapped around the steering column, run underneath the dash and plugged into the OBDII port. It should take ten minutes installation time, tops.

Our little TJ is definitely a work in process. There’s a lot of stuff that needs to be done yet.

When you watch the video, you’ll hear that the TJ’s pretty loud … because it’s running straight pipes. The exhaust was dumping right after the cat when we shot the video. We need to put a cat-back on it, since the old one rusted out. When we picked up the TJ it was fitted with a Dynomax. Nice muffler – we liked it a lot – while it lasted. Alas, rust never sleeps.

Drive a Barbie Jeep? One that never goes off-road? Then you can think about using some low rolling resistance tires.

You’ll want to take a look at TireRack and see what fits. There are a bunch of options for newer Wranglers, including the General Grabber HTS, Michelin Latitude, and Continental CrossContact LX.

There were no options for our TJ in the stock size. But since this little beast ventures off the beaten path, we’re currently running 31×10.50 BF Goodrich All-Terrain T/As.

If you’re going to stick with larger, off-road tires, the one thing that you can do is fiddle with the air pressure.

Never go above the air pressure recommendation on the sidewall.

Always look at your manual, see where the stock specification is, and then, maybe a little bit more.

Adding more pressure in your tire will lower your rolling resistance on the highway.

Remember, if you are off-roading, in the sand, and you’ve taken air out of your tires, remember to air up before you drive home.

We’ve largely been dealing with steering, suspension, and frame issues until this point. Now it’s time to get to work to see where we can squeak an extra mile or two out per gallon of gas.

In our upcoming Jeep Wrangler Gas Mileage Improvement segments, we’ll be replacing the fluids – engine oil, transfer case, and differentials with synthetic fluids, as well as bolting on a new cat-back exhaust.

Stay tuned …

* The only way to get 30 MPG out of a Jeep Wrangler is with a full-on engine swap. HPA Motorsports makes a kit to swap a fuel-efficient torquey four-cylinder Volkswagen TDI diesel engine into the YJ, TJ, and JK Wrangler. The HPA swaps are currently only for manual transmission-equipped Jeeps.

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3 thoughts on “Jeep Wrangler Gas Mileage Improvement Project”

  1. One thing I find interesting about these discussions is the lack of discussion over the value of manual transmissions over automatics. I have had to special order two Jeeps due to the fact less than 10% of the public knows how to drive a manual transmission. My 2006 TJ pulls about 18 mpg with its 6 speed open highway. I am starting to look at trading for a new JK.

  2. @Mark – Yep! I’ve always driven and preferred manuals. There’s a significant difference in mileage in the TJs between the archaic three or four speed automatics and the five or six speed manuals. The kid wanted a manual, initially, then opted for the auto with a justification of “I might plow snow with it.” A year and change later, there’s no plow on it, but hey, we still haven’t seen any real snow yet this season.

    The new Pentastar V6 is an awesome engine, although I haven’t had the chance to test it in a Wrangler yet. Better fuel economy, more horsepower, and faster 0-60 times are a big plus in my book …

  3. Hi
    Can someone out there please explain why the **** you would buy a Wrangler if your worried about fuel consumption!
    Anyway you idiots can placate your concerns by realising that there are plenty of trucks and cars that have far worse mpg figures.
    If you really want an off roader that runs on fumes by a Suzuki and be happy with your toy truck and all those extra $ you’ll have to spend at the local titty bar!
    Better still by a BMX ride naked and live on sunshine ?

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