caught by the fuzz

[thechaddyboy]

just got 3 points & £60 fine for speeding......gutted but guilty - need a bit of knowledge though from the tech-heads.
Q: i drive on 265 tyres & my dials are MPH but the trip & mileometer is still clocking the K/M's..... am i getting a true speed reading, or do i have to allow a bit either way.
cheers for any help with this

[Malenibo]

I have the same. I checked mine with the laptop sat nav displaying ground speed and I appeared to be reading between 6 to 15 MPH higher than the sat nav indicated. I recon if I am showing 85 on the speedo I am actually doing around 70+. I have been thinking about getting it re calibrated properly but not sure where to go. On the SVA test I believe they accept anything up to + or - 25 miles of the speed on the rollers.

The other advantage of mine reading high is that I should not get a speeding ticket.

[Damian]

When mine got SVA'd in May I was told that they would except up to 25mph under, but be just 1mph over and it's a fail.

Laters....

[poppy986]

Hi Andy
If you require a true reading of your speedometer pop it along
to your local tacho testing station where they can put it on the
rolling road.
they will run it at set speeds and you can see the diference
on your speedo either make a note or use a bit of tipex on
the speedo face.
Cheers Chris

[Woodie]

I have 31x10.5x15 tyres but I found an adapter fitted to the gearbox end of the speedo cable, which, I think, if I had standard tyres would make it right but I've found my speedo reads about 12% low. I have tried a couple of tests with friends cars and got the same result. Be carefull.

[thechaddyboy]

Hi Andy
If you require a true reading of your speedometer pop it along
to your local tacho testing station where they can put it on the
rolling road.
they will run it at set speeds and you can see the diference
on your speedo either make a note or use a bit of tipex on
the speedo face.
Cheers Chris

cheers for that, knew i was over the limit but not THAT MUCH !!!!

[Draig]

I've got 31 x 10.5 x 15 - and I've just picked up my 1st speeding ticket - £60 and 3 points.

has anyone got a definitive read-out on tyres and their sizes and what they should read or could read?

[rich]

I don't think there is a definitive answer. My widebody version has 31 x 10.5 x 15 and according to the GPS the speedo is spot on upto 65 MPH where it starts to read higher than actual.

Rich.

[da SLUG man]

and remember that with chunky tread tyres, as they wear, the speedo will be more out than before...

we've had a few trucks that have had the tacho calibrated then got new rear tyres and the speedo's been out.... just by 2-3 mph but it's noticable when you're limited to 56mph

[Gilbo]

Angel

If you use the road angel speed camera detector which we should all have that tells you by gps what speed you are actually doing.
I use a navman pin for gps and a road angel.
The new orange smartphones will accomodate gps and speed camera placements on the phone and is the future and the best bet to travel.

[Gamedawn]

I,ve got the little gearbox thingy on the end of the speedo cable and have calibrated my speedo with a gps. On 31x10.5 ATs it was 8% out and on the 32x11.5 ATs I've currently got fitted it's 10% out - just on the edge of the speed camera tolerance !

[kitesurf_phil]

I got my first three points last year. In a Vuxhall Astra Estate. No excuse there I suppose?

It was a dual carriageway. Houses set well back from the road. Huge park across the road, so I assumed it was a 40MPH limit. It was a 30MPH limit and I was doing 44MPH. The camera was hidden behind a road sign.

I suppose I could have parked somwhere obscure, walked to the tube and reported it as stolen with keys.

[mikey]

Possible defence?

I'll have to look this one up, but if your speedo is legal & having had it officially tested it's found to be outside the required limits, you may have a defence which will be accepted by the courts. Don't mention the tyres!
Re GPS...I wouldn't rely on it for ground speed...it's ok for average speeds over a time & distance, but as the speeds are relatively slow, the satellites can struggle with an accurate calculation. I do a lot of sailing & the speeds are up to about 15 kts. Every now & again the GPS throws up a ridiculous ground speed which is obviously incorrect.
There are other means of avoiding camera fines...working on one at the moment, curtesy of Thames Valley Police...

[Hilux]

speedo

Hi all of my Surfs have been checked with a GPS and tend to read around 2 mmph faster than the speedo is showing, l think its all down to the postioning of the needle after changeing the "Facia".

[Koi]

I know someone who got caught by a static camera.
He said yep thats my car but do you know what I really can't remember who was driving. We used that road about six times that day and both me and the wife drove along it. I honestly can say thats my car but really can't remember who it was that was driving at that time, so sorry.
Never came to anything in the end.