Outer Limits 4x4 Board

Last weekend i was on trip. I drove only 90km/h on highway, 60 to 80km/h on other roads, 40km of trip was offroad.
On map and GPS i was driven for 570km, but car shows only 360 driven.
Speed shown on speedometer was/is the same as speed on GPS - that is tested with 3 different GPSes.

What is wrong, how can i fix this?

Tyres are 235/75/15, feroza is with carburator and with only 83PS.




P.S. Fuel consumption on this trip was 46 liters for 570km - 8 liters per 100km.

The larger tires (stock is 220/75/r15 if i remember correctly) are putting the speedo out.

You will need the speedo recalibrated, quite a few places do that.

But speedometer is fine. It shows the same as GPS (maybe 1 or 2km/h difference), but the kilometer counter is showing wrong. Instead of 570km it shows 360km.

This has happened to me. Someone lubed the speedo cable with grease. Grease gravitated up the outer cable with the action of the inner cable, and worked into the back of the speedo unit, and started to work itself into the odometer. Speedo unaffected, but it may have slowed the odo down.

Now that doesn't make sense... the odometer is directly gear driven... whereas the speedo is driven by a magnetic coupling.

If anything is going to be out because of stiction... it would be the speedo.

If you not running standard tyre diameter then i'd be tempted to say the odo is reading as expected whereas the speedo is out.

Calculate the circumfrenece of a stock and modified wheel.... figure out the percentage difference and if that's what the odo's out then that's your explanation.

Stock Tire - 225/70R15
Tire 1 - 235/75R15

Section Width: 8.85 in 225 mm
Section Width: 9.25 in 235 mm

Rim Diameter: 15 in 381 mm
Rim Diameter: 15 in 381 mm

Rim Width Range: 6 - 8 in
Rim Width Range: 6 - 8.5 in

Overall Diameter: 27.40 in 695.96 mm
Overall Diameter: 28.87 in 733.29 mm

Sidewall Height: 6.20 in 157.48 mm
Sidewall Height: 6.93 in 176.02 mm

Radius: 13.70 in 347.98 mm
Radius: 14.43 in 366.52 mm

Circumference: 86.07 in 2186.1 mm
Circumference: 90.69 in 2303.5 mm

Revs per Mile: 759.1
Revs per Mile: 720.4

Actual Speed: 60 mph 100 km/h
Speedometer1: 56.9 mph 94.9 km/h

Speedometer Difference: - Speedometer Difference: 5.372% too slow
Diameter Difference: - Diameter Difference: 5.1%


From http://www.1010tires.com/TireSizeCalcul ... &reset=yes

5% is not a problem, 500 km driven and odo 480, but 570 driven and odo 360, that is my problem.

Well then i'd be tempted to say you've got a stripped gear / missing tooth / alignement issue in the tumblers of the odometer.

If someones tried to play with the ODO reading to cut back the kms then this is not unusual..

MightyMouse wrote:Well then i'd be tempted to say you've got a stripped gear / missing tooth / alignement issue in the tumblers of the odometer.

If someones tried to play with the ODO reading to cut back the kms then this is not unusual..

thx, that was the problem. There was two missing tooth.