I just had a tune up on my 89 Jeep Cherokee. Is this good or bad??

 

i get 13-15mpg and i consider that awesome, i also have duel lockers, 35" tires, and 4.56's
i also gained about 2mpg recently and a smother acceleration due to injector swap...went with LS1 injectors.

 

that is about what I am getting with 3.07s 5speed and 33/12.5 tires, no less then what I would expect from my current setup.

 

Mine's stock and probably only gets about 18 mpg. in the city. Maybe 21 mpg. on the highway, with a tail wind.

 

i get like 13.5 , and i'm all stock, but i mainly just drive 2 miles to school and to miles back.....daily so never really warms up and averages out.

 

yeah i get about 12mpg with 33x12.5's, and i drive 50+ miles a day mostly highway

 

My stock 99 4x4 gets about 18 around town and about 20 highway but I have to keep it under 70 on the interstate, it has 355 gears so I keep it under 2200 rpms. The worst mileage was from my 06 Commander it got about 16 in town and 19 on the iterstate, it did better but they reprogammed it on a recall and killed the mileage. All the Jeeps I have had run anywere around 17 worst to 09 liberty Wifes city jeep at 22. 01 ZJ 21 hwy, 06 Commander 19 hwy, 09 Liberty 22 hwy and 99XJ 20 hwy. Two 4.0's one 3.7 and one 4.7 but they are all pretty close together.

 

When you did the tuneup did you change the oxygen sensor? Theyre supposed to be changed ~85000mi in a Renix.
Thats not very good if its stock, you should be getting more like 16-17City and ~20highway.

 

I get 7.1 with Swampers and almost 15 with stock tires on.

 

So, what ,if any are some signs you need to replace the sensor. Will the jeep act differently if it is bad?

 

rough idle, fuel smell from exhaust, and less power. also u will fail smog if your state requires it. also with the RENIX system it is **** to blowing the wires out that go to the sensor, so check those with a volt meter before just swapping out the O2 sensor.

 

That is probably what i'm seeing. I noticed this morning wires hanging down this morning on the driver's side. Thank God for forums!

 

Thanks for the info!!!! I will have to ask my mechanic what he did. But ya its all stock. Also when I drive over bumps and pot holes it sounds like something is loose in the front end. I thought at first it was my shocks, but it is getting worse and sounds like something isnt tight in the front. Hope my engine doesnt fall out!!! hahhahaa

 

I feel special, '84 Canada-spec with a homemade 2 (maybe3)-inch lift (blocks under springs and shocks from a Mercedez 240) with 31s and I get 21 mpg...

 

i would first check your track bar, and if its not that then check your tierods. hell to be safe just tighten down all the bolts you can find on your front end!!! (to recommended torque specs of coarse)