350 mile tank in the Jeep Cherokee

[comptiger5000]

I believe that the 5.9 could definitely do better than the 5.2, as long as it hasn't been tuned for regular (normally needs premium). It has great low end torque, so you can keep the RPMs down on acceleration easily (with shifts at 2200, it flies past most cars off the line). With the stock tune, it has pretty aggressive timing, so it not only makes more power, but can be more efficient. Too bad most of my driving is around town (12 - 13 mpg). When I go away to college in the fall, and have a few several hour highway trips, I'll know for sure what my highway mileage comes out to. From what I've seen so far, it's about 1 mpg less than my mom's 99 WJ 4.0, almost equal with lots of hills (less downshifting). It's certainly not bad for an offroad capable, overpowered brick on wheels.

And yeah, stock ZJ brakes suck. They're the same as XJs (about 1000 lbs lighter) and TJs (slightly lighter), but on a bigger, heavier vehicle. For towing, trailer brakes are needed, and a Vanco brake kit would be nice (but very expensive).

[JeepNmpg2]

I can definately agree with the XJ at least needing more brake when towing anything over 2k lbs. I have on a couple of occasions had to pull a friends car with my rig and upon going down a moderately steep offramp of the freeway, found my foot pressing the pedal almost to the floor to stop remotely quickly.... I'd like to find out now how it would work with my new ceramic brake pads . What I'd really like to do eventually is find an excuse to use my electric trailer brake module that's collecting dust in my travel toolbox (probably need to buy a trailer first).

[gascort]

Congrats on the huge (long trip) tank!
At some point, miles per tank is a fun way to judge. I have a 15.4 gallon tank in my Mustang, but I can go twice as far in my Escort on its 12 gallons - pretty cool!
9
I like watching the new car (GM) ads bragging about their SUV that gets 600 miles per tank. I wonder how many gallons their tanks are haha!

[I B RACIN]

Originally Posted by JeepNmpg2

Ok, not so monumental, but this is the longest trip I've been able to manage so far in this rig. The pump only put in 16.8, but the fuel light came on (comes on between 1/8 and 1/4 tank) a few miles before I stopped and I didn't want to push how far the Jeep would make it as there remained 80 miles in my trip. The trip averaged 23.8 and 24.8 mpg respectively each way, but with the in town driving and I think the pump registered more than it actually gave me as there was still at least two or three gallons in my tank. With the exception of this last tank, I haven't had to recalibrate the scangauge with each tank hardly at all so it's my belief that it's being genuinely accurate, just that last fillup threw me off.... by all rights (and with a few aeromods) I'll make that 30mpg highway yet! Next year I have to drive from WA to GA, so my goal is to mod this Jeep enough to make that drive at aforementioned mpg.

what have you done to get that kind of mileage, my son has a 1990 XJ and he only gets about 15 mpg

[JeepNmpg2]

No aeromods or anything yet, just K&N intake, Magnaflow cat, Flowmaster Delta 40 muffler, 30x9.5/15r Yokohama AT-S tires (6% larger than stock), but most important is the scangauge, as it helps me dial in my foot and keep from wasting fuel in "slightly heavier" acceleration to finding what speeds are the "sweet spots" for my engine that allow it to burn less fuel per mile driven. When I mention that slightly heavier acceleration, if I watch my scangauge, it shows how only a tiny bit more pressure on the throttle from your foot equals 10-20%+ worse fuel economy while accelerating. Also, I keep the throttle position sensor up on the gauge, which helps me keep my foot in check from adding too much throttle over time if I'm getting excited or too relaxed. The long and short of it is that you have to take the time to get to know your vehicle, and where it best performs while giving you good mpg. I know that my jeep is capable of giving 15 mpg the whole time too if I'm not driving it correctly

[I B RACIN]

Did you keep track of what each mod did and how it helped mileage?

We are running the stock cat, with a standard 40 flowmaster, stock size pipe, and stock type air filter, stock size tires 373 gears no lift, I just re-set the TPS and that seemed to help some but not enough.

[anomad]

Originally Posted by MadisonMPG

Never will understand mileage per tank.

I mean, you can get 100 gallon tanks for diesels...

No kidding. I had a 35 gallon tank on my old diesel that would pull 25mpg if I was easy on it. And the fuel tank sender was toast, so my fuel gauge always read empty. Only ran it empty once. Nothing like thumbing a ride and bleeding injectors beside the highway in the middle of summer!

Kudos to the OP for such good mileage from a V8 jeep.

[comptiger5000]

The OPs Cherokee is an I6, not a V8. Only Grand Cherokees came with V8s stock.