When was your cooling system last maintained? It's important to stay on top of for the simple fact that XJ's are prone to overheating, but if your thermostat is shot in such a way that it isn't closing when it should, you could be running too cold which would be killing your efficiency, too.

 

Did you take the battery cables off when you put all the new parts on it to reset everything?

 

I just don't want 8 mpg. I can deal with 14 lol

 

I did maintenance on the cooling system about a year ago. The coolant was pretty nasty but I flushed it as well as the heater core. Coolant is now green and temp is standard. New thermostat was put in (195).

 

may be a dumb question but...have you checked the tire pressure(s)? converter locking up? that mileage is terrible. mine when stock got 22+ mixed.

 

Yes, really. Well, unless you consider it worthwhile to think you have "an idea" when in fact, that "idea" is so unreliable that all it can really do is give you a false sense of security.

It's not even close to being comparable to torque vs. horsepower. Those are two very well defined measurements. They can be measured reliably, and understood by anyone who wants to take the time to do so. Furthermore, they have a direct relationship to each other.


The last two or three weeks my "miles per tank" has changed radically. I mean RADICALLY.

My MPG hasn't changed at all. I suspect my sending unit is going out, giving me false readings.

And that's only ONE of the unknown variables in the ignorant, "miles per tank" approach.


"Miles per tank" is code-speak for, "I have not the slightest clue what I'm talking about."

 

 

did you test every sensor? according to the book? coolant temp on the stat housing, iac, map, all so mat sensor? I think? of course city driving kills milege. I got 400 miles out of mine a few times with just highway driving.

 

"Yes, really. Well, unless you consider it worthwhile to think you have "an idea" when in fact, that "idea" is so unreliable that all it can really do is give you a false sense of security."

 

^^^ You have to do it this way. Fill tank until pump turns off. Write down ODO. Drive a good number of miles (say 100), then pump gas again until it first turns off and use the # of gallons from the fuel pump. You can't go by "I filled the thank" and went XX miles and then "filled the tank" and went YY miles. The gauge isn't accurate enough. If you filled the tank until it shuts off and then drove until you ran out of gas, that might work but I don't think you want to run out of gas to see how far you can go.


I used my XJ to go to work for awhile but bought a 4CYL Toyota to commute. The XJ go about 2.5 days on a tank. The Toyota is usually 6 -7 days. Paying for itself in gas savings.

 

thanks everyone for the info. i have some ideas as to what to look at next.

on a side note, i never should have gotten rid of my 95 corolla that thing could run on fumes for a few days if need be.