Hey All,
I just got back from a 4,800 mile trip in my 01 XJ that now has 329,000 miles. On the trip I was getting as low as 14 MPG and 15.5 MPG was not uncommon, but was also getting the more appropriate 18 MPG on some tanks. I know Colorado's high altitude means less power and more fuel economy, but I have driven this Jeep at lower elevations many, many miles and expect 17-19 MPG. Overall any gas I bought in the Midwest would give the bad fuel economy. Once I was buying gas in TN, NC, VA, and MD I was doing better.
The issue showed up on the first tank out of town. I got 15.5 MPG between Colorado Springs and Oakley, KS (still on the high plains). I had it tested for codes and there were none except the "cat efficiency" that's been there for 229,000 miles. Power was as expected and there is no smoke. While in town at some stop lights I sometimes was getting an extra rattle out of the exhaust.
I am thinking it is a lazy O2 sensor that is causing the engine to run rich on at least one bank but it does seem odd that the "Eastern fuel" generally did better than the "Midwestern fuel". As far as I know its all up to 10% ethanol.
Any suggestions?
I just got back from a 4,800 mile trip in my 01 XJ that now has 329,000 miles. On the trip I was getting as low as 14 MPG and 15.5 MPG was not uncommon, but was also getting the more appropriate 18 MPG on some tanks. I know Colorado's high altitude means less power and more fuel economy, but I have driven this Jeep at lower elevations many, many miles and expect 17-19 MPG. Overall any gas I bought in the Midwest would give the bad fuel economy. Once I was buying gas in TN, NC, VA, and MD I was doing better.
The issue showed up on the first tank out of town. I got 15.5 MPG between Colorado Springs and Oakley, KS (still on the high plains). I had it tested for codes and there were none except the "cat efficiency" that's been there for 229,000 miles. Power was as expected and there is no smoke. While in town at some stop lights I sometimes was getting an extra rattle out of the exhaust.
I am thinking it is a lazy O2 sensor that is causing the engine to run rich on at least one bank but it does seem odd that the "Eastern fuel" generally did better than the "Midwestern fuel". As far as I know its all up to 10% ethanol.
Any suggestions?