Hello everyone.
I have a 2000 jeep grand cherokee that has recently been getting horrible mileage. I used to get 20mpg but after I hit a pole a while back, damaging the ac condensor, radiator, and not having driven it for a month, my mileage has decreased to 13.5mpg! What can I do to fix this? I have replaced the spark plugs and so far no luck. Thank you!

 

Winter gas will do this.

 

how does your jeep run otherwise? How hard did you hit the pole?

have you tried replacing the O2 sensor?

I do not how true this is, so don't quote me on this. BUT, I have heard older gear heads talk about gas that sits for awhile, looses some of its volatility, or the ability to easily combust in the chamber. My dad raised me on the 1/4 mile asphalt at Englishtown in the late 70s and into 80s. I also did some offroad racing in So. Cal and Mexico. In both places I heard the same things about gas that sat too long.

The easy fix is fuel additives or replenish with higher octane fuel for the next few fill-ups but let this tank go to damn near empty before you top off.

 

Thank you GI. Its actually been 3 months since I have had the jeep and I have been putting all kinds of additives and adding higher octane fuels and nothing. All I haven't done yet is put on new 02 sensors so I think I might try that.