sudden drop in fuel economy?

[scorpio_vette]

they do actually make alot of noise. i've known for a while that they are really bad. i've just been waiting for some warmer weather to replace them.

i guess that makes since, but i never figured that they would increase drag. if anything i figured they would de-crease drag because they are so worn out and loose.

oh well. i guess i need to get my lazy butt off the couch and do my u-joints.

 

[97cntryxj]

I got the feeling the distributors are playing with the gas again, I've noticed this happen several times over the last couple of years. Just as a test get as far away from your local area, NJ even, and fill up there. NJ is alot more attentive to their gas quality than PA is, all PA cares about is the tax and correct metering on the pumps even if they are pumping water... NJ actually samples the gas and tests it...
Every time our 3 jeeps and the wifes olds go downhill on gas a fill up in NJ confirms it's not the vehicles, literally had that happen 5 times so far.

I have heard of this happening also but i dont beleive this is the problem because my freinds xj is still getting 16mpg while im at 12mpg (we fill up at the same gas station)

 

[goodburbon]

I drove to Galveston yesterday, on the way there I got a little less than 15, and on the way back I got a little less than 20.


I don't know what the hell is going on. There was a crosswind both ways.

Oh, and my CE light is back on......same code, I am at my wits end with that Fawker!

 

[XJ Jeepin Girl]

My mileage fluctuates too. My last tank of gas, I got about 250 miles or so out of it. I've got about a half tank left now and I've driven 155, so it looks like I'll get 300+ out of this tank. Weird... Wish I got mileage like my dad's Jeep, sometimes he gets 23. Must be nice. : )

 

[hippymill]

did you check the resistance on the cts, the mat, and the voltage/vac on the map sensor? also, is you catalytic converter plugged?

 

[BCParker]

I've got mileage issues too. '97 4.0, auto, ~130K

for the past two years highway milage has been around 20-22MPG. over the winter it dropped to around 18, on my last few tanks of gas I'd guess less than 15.

changed plugs, wires, cap, rotor- mileage was better for a week but now is back in the low teens.

o2 sensors and cat / exhaust seem to be next but before throwing money at it I'm gonna try figure out exactly what's wrong.

my jeep has an appointment with the DRM-II and the "driveability" class at the local UTI tomorrow.- I'll update if anything usefull comes from it.