Gas mileage...?

[93GRNXJ]

I get really bad in town (10-15) but freway its crazy 20-23mpg, it just cruzes along at 65-70 mph really well. that is all stock w/ a 4.0

the guy with the amazing mpg does he have the 4-cyl??

 

[rj454]

and a sail?

 

[ZmOz]

I get really bad in town (10-15) but freway its crazy 20-23mpg, it just cruzes along at 65-70 mph really well. that is all stock w/ a 4.0

the guy with the amazing mpg does he have the 4-cyl??

You mean me? Nope....

 

[TekkaMaki]

Thanks for the input, guys. Though I can hardly believe my eyes (wish my smileys worked here), even 12-15mpg would be acceptable, IMO- but 18-22/25 ??? Unbelievable. (Damn broken smileys)
And if I gotta 20gal tank (never got more than 18.something in it), I'm getting 10 mpg if I'm lucky. Of course this is with the oversized tires/incorrect speedo; I will do a search on correcting the speedo next thing. (Damn broken smileys)
In the meantime; does anyone know the math to convert my 200 miles into the correct distance traveled with 32" tires? (I'm not even sure I asked that right.)(Damn broken smileys) Or to figure my actual mileage per gal?
Thanks for the help- RJ

RJ-
Your 285/75r16 tires are approx 15% larger than stock 225/75r15. So if you haven't re-geared or adjusted your speedo gear then you should be traveling approximately 15% further than your speedometer reads. You could correct the speedometer/odometer by changing to a 30 tooth speedo gear. (see HERE on GoJeep's site for more info)

For checking your mileage you should use the trip odometer instead of the size of the gas tank, it'll be much more accurate.
Just fill the tank till the nozzle stops and reset the trip meter.
Next time fill it up till the nozzle stops and make note of the miles on the trip meter and the number of gallons, and remember to reset the trip meter for the next tankful.
Divide the number of miles by the number of gallons to get your mileage (Miles/Gallons=MPG).
More accurately multiply your trip odometer by 1.15 to adjust for the tire size. [(Miles * 1.15)/Gallons = Adjusted MPG]

Just doing the more accurate MPG check should gain you 1-2 MPG.

-Bic

 

[Boris T]

after 2 tanks on my 98 with 4.0\AW-4 3.55 gears and stock tires (225/75r15 Wildcat)

I got 19.5 combined and 17.5 around town. I still need to go over it with some real TLC. I am pleasantly surprised and happy after getting 15 MPG on a good day around town in my v8 Dakota

 

[Dr. Dyno]

I'm averaging 20.8mpg (Imperial) in mixed city/highway driving. If I drive in the city alone, I get high-19's. If I drive on the highway (usually 75-80mph) I get about 21-22mpg. At a steady 65mph cruise I'm getting 25mpg.
________________________________________________________________
- 1992 4.0 XJ Laredo UpCountry with modifications - 173k miles - AX15, NP231, D35c, D30
Estimated 240hp@5250rpm/280lbft@3500-4000rpm, 1/[email protected], race weight 3465lb
- Future mods -
4.6L stroker (under construction)
- Websites -
Jeep 4.0 performance, 4.6L stroker build-up
- Tech Webpages -
CTS resistor trick, Dual electric fans, IAT sensor relocation, Intake manifold heatshield, MAP adjuster, Oil temp. gauge install
- Info Pages -
Automotive formulae, Jeep 4.0 cam specs, Jeep engine dyno graphs

 

[MudDawg]

Have the engine evaluated to make sure it is in good order...a cylinder leakdown test will verify the condition of the cylinder/valve seal...code scan for any faults in the engine control system...pretty basic stuff.

Next to consider is the tire/gearing package...most likely the reason for the poor economy aside from engine problems or a large lead foot.

My '85 mod. 2 door with a 2.5 and 3.73 gearing...stock got 18 city/20 highway.....installed a 6" lift and 12.5 x 33's....corrected mileage fell to 9-10 in town and 12-13 highway, and it wouldn't pull a greasy string out of a cat's butt in high range....installed 4.88 gears...nowdays with a highly modified 2.5 it gets 15 around town and 21-22 highway...