[Background: My '14 JKU is also my daily driver and I don't have room for another vehicle. Most of the year I'm on road and I don't want to be in any other vehicle whatever said and done. I tried searching the forum but this topic was not covered directly so I'm asking this question...]

Why do the Wranglers have so much rolling resistance at every speed? Mine slows down even when going down a small hill. All vehicles slow down with the foot off the gas somewhat but with the Wrangler I don't even need to put my foot on the brake when I see a red light coming up.

Is it all in the tires? I have the stock 255/70/18 ones on 3.73s, soft top and everything else stock (no extra weight). I've driven cars with fairly large alloys and wide tires but rolling resistance is no where near what I experience in the Wrangler.

Anyone got suggestions on reducing it? I'm happy to get a separate set of wheels/tires for use on road and swap over when necessary, if that helps. Or is it in the gearing and there's not much good in changing the tires?

Thanks in advance.

Guy

 

It might be because we drive bricks with wheel under them lol. They aren't exactly aerodynamic.

 

Then it should speed up when I'm downwind

 

At speeds above 25-30 MPH it's aerodynamic drag and increases very fast with speed. At lower speed you got extra spinning part with the front axle and TF. The AT/MT tread on most Jeeps also generates more friction than road tires. You put it all together and you can slow down in a hurry. BTW, it's the same reasons everyone complains about fuel economy.

 

This might be why.

 

Engine braking is part of it, too.
I don't know about the 3.6, but with my 3.8 the injectors shut off when I let off the gas going down a hill, and the torque converter remains locked so it's a solid link like the clutch in a manual. If it's in O/D, it will downshift to 3rd to enhance engine braking if needed.

Any time I don't have to use the brakes on a long downhill stretch is OK by me.

 

Ronjenx is right. My 2010 does the same thing. It doesn't freewheel or coast when you let off the throttle the injectors pulses go to 0 and it helps by offering engine braking plus the trans will downshift as you slow down. It felt weird for my wife at first but for me it felt just like driving a big truck and leaving the jake brake on in a lower setting. I just give it a little gas to keep in rolling. You may can disable the feature but for the hills I drive on I like the extra braking.

 

Don't all modern gasoline engined vehicles turn off the fuel when the peddle is let go at anything but very slow speeds? I haven't noticed as much a slow down In others. Could it be that the engine is under compression (which makes it harder to turn) instead of having the valves open until the peddle is pressed again or the free rotation rpm is low for an idle restart?

I'm not that fussed about fuel economy because the evic shows just under 31MPG when I'm driving ultra careful on some of the slower roads. Sure... in the city it goes down to 18MPG or worse.

 

Auto or manual tranny? You can declutch your manual to let it roll off the hill. The auto will always drag due to the engine brakeing.

 

Another reason is that the front axle can't be unlocked, so it adds resistance. Going to manual hubs would add an easy 1-2 mpg. Plus, it would drive better. Not only are the front shafts and gears turning, but so is the front driveshaft and that turns the front of the T case. Talk about a waste of energy.