???can you work it out???

[strongy]

ive just been out with a gps to get the true speed on my bus as ive got smaller wheels,what its told me is that when my bus says 60mph it is actually doing 50mph,so with this info is it posible to find out how much a mile is as this reading will be out aswell???

 

[gninnam]

Using GPS in cars, I find TomTom tends to read 4 to 5 mph slower than the speedo reads and that is at most speeds (ie 30 to 120 :wink: )

Hope this helps a little

 

[Justin & Muttley]

Is this what you mean?

Speedo Actual
60 50
55 46
50 42
45 37
40 33
35 29
30 25
25 21
20 17
15 12
10 8
5 4
0 0

Your actual speed is 83.33% of your speedo speed!!!

 

[Guest]

yup your gps will always read the correct speed and its usually 5-6 mph slower than your speedo. thats why the cops let you away with 10% ie 66mph in a 60.

 

[strongy]

thats it j n m,what i was wanting to work out tho is speedo reading .say i do 100 miles how far have i actually gone?

 

[speedwell68]

thats it j n m,what i was wanting to work out tho is speedo reading .say i do 100 miles how far have i actually gone?

Based on the 83.33% theory, which is a good one. For every 100 miles driven you will have covered on the road only 83 miles.

 

[strongy]

thanxs

 

[slammedkustom]

thats almost like time travel! :shock:

 

[Shaggy]

I wonder if he has a flux capacitor :?:

 

[jabbo]

Like Johnny say's speedo's are calibrated to show a speed faster than they you are actually going, so most of the difference will come from this, not your tyre size. Stupid really. :?

Slightly OT, but with my Passat I can enter various codes to get the true speed/MPH etc through the climate control display, and like you say it's usually about 6% different.

 

[VWAIRCOOLED]

With standard wheels/drivetrain the trip counter should be accurate and the speedo optimistic.With smaller wheels your speedo will be even more optimistic and now the tripcounter will be optimistic too!

Maybe follow a known standard car of a distance of 10 miles and compare readings.Then you will know how many miles to take off for every 10 miles travelled.