'92 4.0 I6...dumb question

[Dvipercop]

Well I was doing some searching on how to replace the O2 sensor in my '92 because I've heard that is one of many causes for getting lower gas mileage. That aside, what size gas tank came standard on the 92's? For some reason I thought they had 20 gallon tanks, but the more I thought about it, the more I realized I've never had to fill it from empty. The reason I ask is because I'd been basing my mpg on a 20 gal. tank setup. If indeed they came with smaller tanks than that would mean my mpg is better than I originally thought. If there is anyone still with me on this, what are some things to begin replacing that would help with getting back some of that lost mileage? 1992 4.0 I6, 235,000 miles, K&N cone-filter, 3" lift, 30's...

 

[langer1]

Well I was doing some searching on how to replace the O2 sensor in my '92 because I've heard that is one of many causes for getting lower gas mileage. That aside, what size gas tank came standard on the 92's? For some reason I thought they had 20 gallon tanks, but the more I thought about it, the more I realized I've never had to fill it from empty. The reason I ask is because I'd been basing my mpg on a 20 gal. tank setup. If indeed they came with smaller tanks than that would mean my mpg is better than I originally thought. If there is anyone still with me on this, what are some things to begin replacing that would help with getting back some of that lost mileage? 1992 4.0 I6, 235,000 miles, K&N cone-filter, 3" lift, 30's...

Huh? Why not write down the gallons and mileage between fillups?

 

[viperbaron]

Yes, that is what I do. Record the milage. Record the fuel purchased (filled up with). Divide the miles by the gallons.
Start from scratch;
1. go fill up.
2. Before leaving the gas station, write down the milage.
3. drive until you need gas again.
4. Fill up and record the gas purchased.
5. Subtract the recorded prevous mileage from the current mileage.
6. Divide the traveled mileage by the gallons of gas.
Bingo!
My '98 has a 20 gal tank. Gettin' 19 in town and 23 hwy...2WD only.

 

[Dvipercop]

Admittedly (sp?) it was a retarded, and dare I say asinine, way of doing. I have since learned a better way (what you mentioned). I'm only getting approx. 10-13 city and up to 15 freeway. From all I've read here, these figures suck. Any ideas where to start on trying to improve MPG? I've read many a post that have to do with a failing or shot O2 sensor being a culprit. None mentioned the location of said sensor though.

 

[langer1]

Admittedly (sp?) it was a retarded, and dare I say asinine, way of doing. I have since learned a better way (what you mentioned). I'm only getting approx. 10-13 city and up to 15 freeway. From all I've read here, these figures suck. Any ideas where to start on trying to improve MPG? I've read many a post that have to do with a failing or shot O2 sensor being a culprit. None mentioned the location of said sensor though.

It is down on the drivers side of the engine, sticking out of the exaust header.
Standard or Automatic? Have you checked the Cat?

 

[Dvipercop]

Sorry, shoulda been more specific, it's an auto. I haven't checked the cat yet. Is there a good way to do it? How will I know if it's clogged/useless? That was another thing I was thinking about replacing in the near future, for the sole reson that I want a high flow one and I think it would make my Cherry Bomb sound better.

 

[RichP]

Did YOU put the 30's on and if so did you also do the spedo gear in the transfer case ? If not then your true miles are not right.

 

[langer1]

Did YOU put the 30's on and if so did you also do the spedo gear in the transfer case ? If not then your true miles are not right.

.
Good catch, that would through the calculation way off

 

[Dvipercop]

No, it came with the 30's on it and I haven't touched anything with exception of the air intake and exhaust. Why would the calculation be off? Isn't the stock tire size 30"?

 

[RichP]

No, stock size was either 215 or 225's, if the previous owner did not do the gear thats the first thing you need to do to get your true miles. Off the cuff, you probably have a 10-12% error rate. Less miles are showing on the odometer than you are doing, spedo will also be off same amount, reading slower than you are going.