MPG overhead display correct with 35's?

[dcxj1990]

Is my overhead MPG display reading the accurate MPG i am getting?

I have 35's with stock gearing?

 

[GSequoia]

No, it is not.

 

[dcxj1990]

its gonna show that I am getting worse correct?

 

[H8PVMT]

Where did you get an overhead mpg gauge? If its reading worse than your getting, it would be around 6

 

[dcxj1990]

overhead meaning the display on the roof, above the rear view mirror, with the interior lights and sunglasses holders

 

[egotripp]

Install the correct speedometer gear in your t/c for 35's and your gear ratio. This will correct your mpg and odometer. You are putting more miles on it now.

 

[dcxj1990]

well at least I am getting beter then it shows lol, cause its showing 6mpg going uphill, but average of 18mpg going down the highway, so better then that is always good lol

 

[rockclimber]

actually... shouldn't you be getting worse than what it shows, since you are putting more miles on the ODO than you have actually traveled...

 

[GSequoia]

actually... shouldn't you be getting worse than what it shows, since you are putting more miles on the ODO than you have actually traveled...

Exactly.

 

[dcxj1990]

is it?, I still have stock gearing

 

[scoobyxj]

actually... shouldn't you be getting worse than what it shows, since you are putting more miles on the ODO than you have actually traveled...

No it's the other way around. Bigger tires means the drive train rotates less for the actual miles driven. Which means your speedo will read you're going slower than you actually are. There fore your ODO will read less miles than you actually traveled. You could use a GPS app for your smart phone to keep a tally of actual miles driven for a tank of gas, and use that to calculate your mileage.

 

[dcxj1990]

No it's the other way around. Bigger tires means the drive train rotates less for the actual miles driven.

right, thats my understanding

 

[GSequoia]

There's no way he's pulling above 18 highway with 35s and 3.55s (or 3.07s).

 

[dcxj1990]

Id have to look at the code (if there is one), but I am pretty sure I am running 3.55's

and according to the MPG display thats what I am getting

the jeep is not to bad on take off either, Im not sure if the PO had gears installed or not, is there a simply way to find out besides removing the diff cover and doing whatever is involved

 

[rockclimber]

Id have to look at the code (if there is one), but I am pretty sure I am running 3.55's

and according to the MPG display thats what I am getting

the jeep is not to bad on take off either, Im not sure if the PO had gears installed or not, is there a simply way to find out besides removing the diff cover and doing whatever is involved

if you have an open diff... or selectable locker... jack one rear tire off the ground, rotate it one revolution, count the revolutions of the driveshaft. if its 3 then its 3.07, if its ~3 and a half its 3.55 if its barely more than 4 its 4.10 if its ~4 and a half its 4.56..etc etc etc...

if you have a full-time locker/spool you will need to jack both tire soff the ground :jester:

 

[GSequoia]

Counting teeth is the best way to tell.

 

[rockclimber]

Counting teeth is the best way to tell.

he said without pulling the cover

:rtm::looser:

 

[GSequoia]

he said without pulling the cover

:rtm::looser:

I know. Just because it's outside his spec doesn't mean it's not the best way.

 

[kdailey4315]

My XJ is stock and my OH display isn't accurate for MPG.

Sent from my phone using the magical invisible interwebs.

 

[rockclimber]

I know. Just because it's outside his spec doesn't mean it's not the best way.

stop clouding the issue with facts.