I just bought a 1998 Jeep Cherokee Classic here about a month ago, It had 144,xxx miles when i bought it. The first week i got it i changed the spark plugs, wires, air filter, and changed the oil with Mobile 1 Fully synthetic oil before driving to Baton Rouge, LA, about a 950 mile round trip from where i live (North East Arkansas) The jeep is great, no rust, everything works great on it, except thirst for gas lol.



I got to talking to a friend of mine with a 99 cherokee identical to mine, except his has a 4 inch lift with 31x10.50 tires along with a roof rack. He was saying he was getting like 16mpg in town and 21-23 on the highway compared to my 15.5mpg highway (at 70) and like 11 in town and i only have a 3 inch with 30x9.50 tires

The only difference between the two of ours besides the lift and tires is he has done the injector swap and removed the cat.

[Questions]
Now my question is do the "neon" injectors make that big of a difference?

What are some other things i can do to improve my gas mileage? (Cold air intake, exhaust, etc)

Also i have been reading and noticed everyone saying injectors for 99 and up cherokees. will they also work on my 98?

Any other ideals or input is greatly appreciated also



Thank You,
Brandt

 

buy smaller tires or regear
you can buy a lot of add ons and spend a lot of money. buy your tires are too big and your gears are too small to ever really get decent fuel economy
and ditch that synthetic oil quick

 

Just Bought a 1999 Cherokee Sport pure stock. Will it get better mileage??

 

Nothing wrong with synthetic oil, but not here to debate that. Lots of things you can do to improve gas mileage. One of the first things you should do with a new Jeep is change the oxygen sensor(s). But yeah, your friend probably does not have stock gears, which will help him out a ton. Any lift with bigger tires will kill gas mileage

 

He has factory gears, I understand lifts and bigger tires dont help but his Jeep has an inch more lift with an inch taller and wider tires than mine along with a roof rack and pulling better mpg in town than im getting on the highway. He also has a throttle body spacer and has bored out his throttle body.

 

A bored throttle body and throttle body spacer have no effect on mileage, although many people believe a spacer will boost your mpgs by 1 or 2. In your case, check your exhaust manifold for cracks and replace the upstream o2 sensor(s) if you do not have written record of when the past owner last changed them - I believe I've read that the later year XJs have 4 o2 sensors total. I'm not 100% positive about that though. That's a good place to start.

Edit: Oh and congrats on your purchase! I've always liked that color on the later XJs. Looks good man

 

First of all i would say stay away from sythetic oil i ran it once in my cherokee and i think its too slippery just saying secondly is an air intake is a great upgrade for power and gas milage, I went from 17 hwy to about 20-22, the K&N cold air intake cost bout $300 but easily paid for it self

 

Oh and to answer your question about fuel injectors, no you won't see a big difference in MPGs. A few people out of the MANY that have installed these, have seen maximum of a 1 mpg boost, while the majority do not see a boost in mileage, myself included. They do give you a smoother idle and better throttle response, which is worth buying or finding in a JY in my opinion. There are different neon injectors that will fit your specific year. If you do more research, you'll find that the injector plug was changed sometime in the year of 98. More than likely you will need the 703 neon injectors but you need to verify whether your injectors have the EV1 or EV6 plug.

Back to mileage, there unfortunately isn't some secret trick to boost mileage by 10 mpgs. Routine maintenance is the best way to keep it running most efficiently, like fresh fluids, tune ups when needed, fresh o2 sensors, making sure vaccuum lines are clear, making sure sensors are operating properly, etc. Things that affect aerodynamics will make or break mileage, as well as exhaust leaks. The thing that will help you the most is regearing. Also, your speedometer is off a tad with your lift and tires, not giving you an entirely true calculation. To fix that, you'd need to change your speedo gear.
http://www.jeep4x4center.com/jeep-speedometer-gears/index.htm