Safe Speed Forums

So to sum up;

A speedo is not required for an MOT
A speedo does not have to be accurate for an MOT
A speedo only has to be accurate within a tolerance of 10% when the car is new
A speedo can be affected by tyre size and wear
A speedo can be affected by wear and tear
A speedo can be affected by magnetic interference (most)

But we are expected to drive within a few mph of a number on a sign and having an inaccurate speedo is not a reasonable defence because it is our responsibility.

Seems fair

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Ross

Yes I'm a hoon, but only on the track!!!!

Not at all - you can drive well below the limit, and give yourself even more margin. Margin is good. If you are not sure about your speedo, stay on the safe side.

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I stole this .sig

They do not check the speedo, when they are new!

Recent purchase of crew bus for work, new 2004 model, GPS reading 40mph, speedo reading 45 mph.

go figure

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Steve

And just what am I supposed to do about the line of enraged drivers behind me who want to kill me by overtaking in the most dangerous places because they are so frustrated?

So for the average punter, without a GPS system to confirm their speed, the idea is to drive well below the limit just in case the speedo is out.

If you have no reason to doubt your speedo is accurate and you are pinged for speeding because of it whose fault is it? There should always be a reasonable margin allowed as the speed limit was always intended as a guide to an appropriate speed and has only recently become an absolute maximum.

In Victoria, Australia, we get booked for driving over the limit by 2-3mph so you can see just how unfair that is.

Can you ABSOLUTELY GUARANTEE that your speedo is that accurate?
Can you ABSOLUTELY GUARANTEE that you have never crept over the limit while going down a hill by 2-3mph?

If it's happening here you can bet it will either be happening there now or will in the future.

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Ross

Yes I'm a hoon, but only on the track!!!!

While it's probably easy for most people to stay at a particular speed without constant reference to their speedo as long as their speed is reasonably steady, the same cannot be said true for a lot of urban driving and driving in traffic. If you're constantly slowing down and speeding up, as traffic and conditions dictate, it's all too easy to overstep the limit without realising it - unless you're watching the speedo instead of the road.

Regards
Peter

I have a little pocket GPS which I use for sailing, walking, driving etc and which I sometimes put on the dash.

My previous car, which was a Vauxhall Omega, had a speedo which was absolutely spot on. My current car (Volvo S60) has a speedo which is 7-10% fast across the range.

I wasn't particularly impressed with that, so I wrote to Volvo asking if there was any way to calibrate the thing properly. They replied that speedometers in new cars can read up to 15% fast but they must never ever read slow, so theirs are set at +7% to allow for manufacturing and tyre tolerances. You might get a good one or you might get an awful one. I guess mine is averagely awful and when I drive I compensate for the speedo error.

But last year I was on holiday Down Under (with my GPS) and drove several hire cars, all Holden Commodores, and they were all spot-on! If a mass market manufacturer like GM can get it right, why can't an aspiring premium brand like Volvo? Grrr.