Speedo and TomToms

[Scooby Pete]

Just got back from collecting our new puppy. 2 hour drive up to Swindon to collect her. Car ran like a dream set the cruise control for 80 and just cruised along good as gold.

Btw did you know that your speedo under reads by at least 5 mph?

The speedo said 80 the TomTom said 74/75. Which is more accurate tom tom or the car?

I've always gone by the TomTom myself.

Haven't used it before with the Hatch as I had a pioneer sat nav system fitted and that doesn't display a speed. So I had the TomTom out just to see how much the speedo was out compared to the TomTom.

[Gambit]

Tomtom is. All cars are set more then what they read. Some bed time reading ;)

The UK law is based on the EU standard, with some minor changes. A speedo must never show less than the actual speed, and must never show more than 110% of actual speed + 6.25mph. So if your true speed is 40mph, your speedo could legally be reading up to 50.25mph but never less than 40mph. Or to put it another way, if your speedo is reading 50mph, you won’t be doing more than 50mph but it’s possible you might actually only be travelling at 40mph.

[stants]

Arrgh speed camera ! Even if everyone knew this info wouldnt stop stamping on the brakes every time the come up to one ! Which if you go by that calculation and if the camera is set at +3%you'd have to be doing an indicated 48-50 to get caught.

My phones gps gives a slightly different rrad to the tom tom ?

[Scooby Pete]

so how does the police laser come into it.

 

Surely this means if you've been stopped for speeding in a 50 by a Copper with a laser then you were deff doing an indicated 60+ and have no complaints.

[stants]

Game over there i'm afraid. Only thing you could do is ask to check the calibration cretificate maybe check their car see if theres a bulb out :-D

[Gambit]

How do you mean if you was doing 60 on the speedo in a 50 zone it would be around 56/54MPH give or take a little. So would make you breaking the speed limit I think most are set to allow about a 3mph over the limit so getting zapped doing about 58 on the speedo would still mean you was speeding by around 3 to 4 mph. Have you not seen how many people have been done for speeding by about 5 mph over but the speedo would have shown more. If that makes sense :) 

[stants]

Yeah sorry my post was mis worded really.

People slow down through cameras cos they think they'll get snapped doing dead on the indicated speed in reality the speedo's out and the camera has some + variance.

[mfnick]

Everyone else has already said but yea, the TomTom will be more accurate. Speedo's always read slightly higher.

Imagine how much **** the car companies would get in if you could lay the fault with their speedo. Making it read higher accounts for small variances and makes sure this wont happen.

[Scooby Pete]

I know what you mean about the variance in cameras, I live just off an A road and there are 2 cameras on the same stretch facing opposite ways. One didn't go off when a cop car went through at 55 yet the other side goes off at 45. We seem reasonably lucky in that there are only a few speed camera guts in our area and they don't seem to move them around that often. Prob just leave them in the most profitable cameras.