I was getting this much a few months ago but it dropped down 17.2. A lot had to do with my tires being under inflated. I slightly over inflated them and now the Jeep's back to rolling like it's on ball bearings when I coast in neutral. Also, it accelarates (accelerates?) a lot easier. The difference in rolling resistance between just a few lbs of air is truly amazing. You can really feel the difference.

 

What's your gearing. The reason I ask is that the best we get in town is about 14. Mixed town and highway about 18 and strictly highway about 21.
That's a stock unlimited, auto with 4.10's.

 

what psi are u setting your tires to?

 

I tend to get better mileage around town actually because there are more opportunities to coast in neutral, drive slowly, keep the rpm down, shut the engine off at red lights, etc. I'm very much babying the Jeep when I drive.

Gearing's 3:21 which has a lot to do with it of course given the 4 speed auto.

 

40psi, which is 5 psi above stock, which is a pretty common recommendation on websites that promote improving your mileage.

The thing about driving with obtaining the highest possible mileage in mind is this: you can't foul up. If you want to see the highest results, you can't gun the throttle here and there or drive fast on the freeway. You have to drive very conservatively all the time. You'd be surprised how much fuel is lost when you gun it just once. Of course if you're throttling it consistently and getting 13mpg, you'll see big gains by just throttling it half the time and I understand if maxing out mileage isn't for everyone, but there's a balance that most people are probably interested in. It's those unnecessary things you do that kill your mileage, such as gun it off the line when a slow accel will do just as well, driving 65, 60 or 55 will get you there not much longer than if you did 75 or 80, hitting the gas when you're only coming to a stop sign in 1/2 a block anyway so you might as well coast. Also idling KILLS mileage. So much gas is lost at idle it's unbelievable. I shut my engine off at redlights; huge difference. Stuff like that. 19 mpg is 427.5 miles per tank and with a summer blend I'll get 19.5 mpg. You could also draft off of bigrigs for another couple mpg's on the highway but that's not fair to big rig. I've had Prius's come up and tailgate me trying to draft and that's lame because they're creating more drag for me and hurting my mileage.

No we didn't buy our Jeeps for mileage but getting better mileage is like paying less for gas. If I had a stick I'm confident I could get 25mpg.

 

man... you get 5-6 mpg more than me. My jeep only has 2 doors too. Does it ride much rougher at 40psi? If I had the money, I would get the turbo just for the improved gas mileage. No, we did not buy these things for mpg... but it is really nice to get better than 10mpg.

 

I, personally, wouldn't be doing that... shutting engine off for such a short time... you are putting more stress on the motor when you go to restart the engine.

 

I disagree. I did this for 170,000 miles on my toyota and the thing was still running a champ at 270,000 miles. Zero engine problems. Also, hybrids do this all the time. Where would the extra stress be coming from? It doesn't take extra effort to start a vehicle that's a myth.

I read in another thread that someone's getting better gas mileage with Bosch +4 IR Fusion spark plugs. Anyone else get better mileage after upgrading their plugs?

 

I had a 126 mile round trip commute to work this past summer, and just about all of it was highway driving. When gas was $4 a gallon, I didn't drive anywhere except to and from work. Bone stock, I would average 20.1mpg when traveling West (against the wind) and when I would draft a semi on my way back East (with the wind) I would get, believe it or not.... 23 mpg. With an auto and 3.73's. Granted, that's the onboard computer, so who knows if it's right... I also put the tranny in neutral at stoplights, lowering my rpm's down to about 600, this helped a little bit. I only took these measures b/c of the high price of gas and my incredibly low pay at work. I would literally put $150 of gas in her per week. That SUCKED. I didnt buy my Jeep for mileage, If that was my main concern, I'd buy one of those hippie hybrids and weave my own sandals, But saving a few dollars here and there by smarter driving and sometimes cheating (drafting) was a good option for me at the time.

 

Yes I believe you got high numbers when drafting. Maybe not 23 because the computer's a little off, but somewhere up there sure no problem. All these little things make a huge difference.

As for the 40 psi the ride is actually much nicer because the Jeep just responds better. Less friction. It moves nicer along the road. When my tires were at 33psi at one point, it felt like it was engine braking whenever I took my foot off the pedal. Now with the 40psi it just glides when I put it in neutral and coast. Big big difference. Of course, though, I'm really paying a lot of attention to this so it might not be so noticeable to others.