Gutted

[colinrob]

Just brought a snooper GPS alser/rader detector anyway the GPS gives a true speed reading here are the figures speedo against actual (4.0 tvr chimaera)

Speedo 35 Actual 30
Speedo 60 Actual 52
Speedo 80 Actual 70
Speedo 130 Actual 110 (on a private road!!!)

How many other people have found this when checking against GPS?

[AllTorque]

That's probably why I still haven't got a NIP from the Griff! Good ole TVR, saving our hard-earned...

[trefor]

Not that far out - mine reads about 4mph over at 90, 3mph over at 70 and 2mph over at 60.

[tonyrec]

Not good at all........just had mine tested against Pilot/Vascar and it showed 105 at a true 100mph.

[danhay]

Isn't it illegal for the Speedo to overead by more than 10%

[Sidekick]

Yep, my Noble reads 77 when the GPS is on a steady 70

[UpTheIron]

colinrob said:

Speedo 35 Actual 30 Speedo 60 Actual 52 Speedo 80 Actual 70 Speedo 130 Actual 110 (on a private road!!!) How many other people have found this when checking against GPS?

Pretty much the same as mine (2000 Chim 450)

[tonyrec]

Those speedo readings would cause me genuine concern.

[pies]

tonyrec said:

Those speedo readings would cause me genuine concern.

Why? it would only really concer me if they were the other way round

[Mr E]

Mine is also well out.

Indicated:Actual GPS speed

30:27
40:37
70:66
74:70
123(ish):112 (disused runway I'll have you know)

I say 123ish as I was rather busy at the time. Still have a 112mph limiter on the car, so that was the lot.

Not too bad. Within 10%.

[tonyrec]

pies said:

tonyrec said: Those speedo readings would cause me genuine concern. Why? it would only really concer me if they were the other way round

Sorry, meant to say that the accuracy gets worse the higher that you go.

[goodlife]

Sidekick said:

Yep, my Noble reads 77 when the GPS is on a steady 70

Noble have needed to design a new speedo pickup for the cars fitted with a 6-speed gearbox. They've tested it to 160ish and reckon it's frighteningly accurate!

[dick dastardly]

tonyrec said:

pies said: tonyrec said: Those speedo readings would cause me genuine concern. Why? it would only really concer me if they were the other way round Sorry, meant to say that the accuracy gets worse the higher that you go.

Don't drive so fast then cheeky!

[Sidekick]

goodlife said:

Sidekick said: Yep, my Noble reads 77 when the GPS is on a steady 70 Noble have needed to design a new speedo pickup for the cars fitted with a 6-speed gearbox. They've tested it to 160ish and reckon it's frighteningly accurate!

As I feared , Looks like I'm gonna have to buy myself one of those new 6 speed gearboxes - hopefully Lee'll throw the speedo pickup in for free!

[Richard C]

[quote=danhay]Isn't it illegal for the Speedo to overead by more than 10%[quote]

Only at 30 mile/h. The speedometer can read higher than GPS on other than a straight line track as GPS speeds are averaged out over distances separated by at least 10 seconds. ie the GPS speed is as-the-crow-flies but speedo speed is relatively instantaneous

[Ultra Violent]

173 mph on speedo (digital), 172mph laser speed trap (brunters) in 964 Turbo.....

[Graham]

tested the chim one on a rolling road all the way to 130 and it was + or - 3 mph all the way


(130 was actauly 131 on the rroad!!)

[schford]

My Tamora - is exactly accurate with my GPS, pretty amazing I thought as I thought nearly all speedos over read.

[cazzo]

tonyrec said:

Not good at all........just had mine tested against Pilot/Vascar and it showed 105 at a true 100mph.

Private road, I assume Tony?

[ribol]

Even if the speedo is spot on when the tyres are brand new (unlikely) it must be reading well over when the tyres are on their last legs. There must be probably a good 20mm difference in the diameter of the wheel/tyre. I suppose it may help cut down motoring tax, sorry, camera fines. I wonder how many miles our cars have really done.

Must check out that Chimaera 130mph/110mph reading, next time I do the MacDonalds drive thru

Ivan