87 wrangler...horrible gas mileage

[SVTballa]

i have a 1987 wrangler with a 2.5l i4 and im gettin about 180 miles on a 13 gallon tank. this is not very good at all concidering i have really small tires. they are just street radials not even A/T's on 16s. is there a way to better my mileage. i already replaced my spark plugs, ignition wires, distributor cap and rotor and this has seemed to help alittle bit. any advice would be greatly appreciated. thanks alot.

[rob doggy dog]

the best thing you can do to save gas is not to lay into the gas pedal on take offs and accelerations just take it easy if you never press your pedal in more than about 1/2" your secondarys on the carb wont open and suck up all that gas! also remember jeeps are not made to be efficient and the gearing is low so shift up as much as possible and keep the rpms down when you can if you are just cruzing around and especialy on the freeway ,..raceing around uses alot of gas , hope that helps some rob doggy dog

[SVTballa]

ya the jeep is definatly not geared for highway use.ya i try and take it easy as much as possible but ive got TBI its not carburated

[Ray H]

Originally Posted by SVTballa

ya the jeep is definatly not geared for highway use.ya i try and take it easy as much as possible but ive got TBI its not carburated

What size tires are you running? Up above you say 16s. Those arent stock wheels, are you running low profile tires? If you have tires less then 28" dia. you are probably losing most of your mileage at highway speeds. If thats the case, slow down some on the highway or get taller tires.

[fredjacksonsan]

If your vehicle has a bad O2 sensor, that could cause poor mileage; you didn't say if it was automatic or manual transmission. No matter; replacing your fluids with all synthetics could get you a 1-2 mpg increase.

[SVTballa]

ya the tires i am running are P215/75R15 they are just little tiny street tires. off road is not capable with these tires. ive got a 5 speed manual

[fredjacksonsan]

How many miles?

I had a 97 with the same size tires, and got 17mpg everywhere, from the highway to driving in sand @ the beach. I never checked the O2 sensor on mine, but it may pay you to do so.

Are there any issues with how the Jeep runs? High/low rpms ok? Power the same? Does it run smoothly or rough? Is your air filter clean?

[SVTballa]

ive got 108000 miles on it. i guess thats not bad for an 87 but i have worked on it to get it running smooth. it turns on no problems idles just fine it purs like a kitten. but i think if i get a new o2sensor that should help alot cuz idk when it was last changed or checked. ya my filter is clean i just replaced it.

[fredjacksonsan]

There's been a lot of posts about an errant O2 sensor causing the mixture to be really rich...which would cause bad mileage.

[SVTballa]

o. well i guess illl check my o2 sensor and see if that helps. thanks for the help.

[4x4grey88]

I have a 2001 with 2.5L (with 33" tires) and replaced the following to increase speed and milage:

Cold air intake system (With K&N fliter)
Throttle body spacer
Live wires spark system
Replced the OEM clutch with an electric fan

This cost a little bit, but in the end run it will pay for itself. MY Jeep has more pep and better milage.