Speedo Reading

[WOO5IE]

Just returned from a pleasant 150 mile drive from Essex to Kent using the M11 and M25. Surprisingly it was clear so I could keep to around 70ish for most of way. I also had my Tom Tom on as I didnt know the the exact whereabouts at the distant end.

I was checking the Tom Tom speed reading with the Chims speedo and the speedo reading was always around 10% higher. Its not a problem in fact it could be a bonus for radars, speed guns etc. I have standard wheels and tyres fitted. I would have thought the Tom Tom was more accurate. Would this also make the mileage reading 10% higher as well.

Trev

Edited by WOO5IE on Saturday 8th March 12:14

[2 sMoKiN bArReLs]

Yes, mine's the same. (Although on average TomTom is 3% short, as it takes no account of undulation.

So true mileage error is 7% ish

[2 sMoKiN bArReLs]

Note: Essex to Kent is flat, so somewhere somebody drove through Snowdonia to keep the 3% average up

[thegman]

mine reads bang on same as tom tom

[WOO5IE]

Should I pump the tyres up for more acurracy

Trev

[kailear]

I set my Tom Tom to make a stupid mooing sound at a speed exactly equal to my national speed limit; I also noticed that my Chim's speedo was consistently reading c.10% higher than the point at which the moo sounded. So I have decided to milk the discrepancy and just drive faster.

[2 sMoKiN bArReLs]

WOO5IE said:

Should I pump the tyres up for more acurracy

Trev

That'd make it worse!

[Ubernoober]

thegman said:

mine reads bang on same as tom tom

ditto - but over *** its about 2-3mph higher than TT (allegedly)

[dogbucket]

my chim is fairly spot on, my mk5 golf is nearly 10mph out at 70mph.

[Red V8]

Mines around 10% over too... makes me feel like I'm having more fun though... improves the 0-60 time, and keeps me the right side of the law.

Edited by Red V8 on Saturday 8th March 11:37

[WOO5IE]

If the reading is 10 % higher does this mean that the real mileage is 10% less. And therefore the MPG 10% worse.

All this is subject to Tom Tom being more accurate

Just a thought.

It does make a bit of a mochery to some the of the arbitrary speed limits/Traps

Spell check would be a good idea on this forum for us non spellers!!

Trev

[Red V8]

You can get plug in spell checkers for your browser e.g.

http://www.iespell.com/download.php