[djed]

i check my speedo the other day against the GPS. With 30 inch tyres doing 100 km/hrs it read 102km/hrs on the GPS.
i am guessing the spedo must have been out about 8 or 10% from the factory to account for any margin of error and with the bigger tyres it reading just about right.

Is it safe to assume the current odometer would be accuracy, or would it be 10% lower than actual?
Just want to check my fuel consumption accurately.

[kuta]

i now have 235 75 15 on mine and im about 10 kmh out. tested it the other day by following the wifes car she was doing 60 i was doing 50 in a 70 zone my speedo was 60 and she was doing 70. even with gps in car speedo is about 10 out with stock gearing tho. follow some one you know and get them to stick to the right speed is the best way i think.

[pezz]

kuta wrote:

follow some one you know and get them to stick to the right speed is the best way i think.

hardly the best way....

find a speed camera that is in a 60 zone,
go past it at your speedo reading of 100kms/hr,
wait for the print out in the mail,
it will tell you your actual speed,
you will have to pay for this service,
they conveniently graft the bill onto the speed print out,
at a additional cost you can also request a photo of your car

[kuta]

was going to wright dont find out like my m8 did 52 in a 40 school zone and his speedo was 40. $$$$$$$

[BlueSuzy]

Your odo will be 13% out. Enough for a defect technically.
You could adjust your speedo internally in the cluster to suit you tyres more, But it wont change your odo.



http://www.lepayne.com/gears.html

I was just playing with the gearing on mine then realised you asked this question. Adjust diff gears and tyre size to get the difference from stock.

Mine is 14% out. I need to change the speedo gearing for engineering, or run 4.88's and rev 4500rpm @ 100kph to fix my odo..

[djed]

just checked mine ODO by getting my GF to drive the forester behind.

the zuks ODO was 11-13% lower the forester’s ODO after 10 km.

So in theory my fuel consumption of 15 L/100km is closer to 13.3l/100km ??

[BlueSuzy]

Makes it abit harder because the forester will be somewhere in the 10% range also

I would rely on the gps more

[Joshua02]

I have 235 75 15, and my spedo is out about 5 kph out and my fuel consumption is threw the roof-.-