speed limits

cyclonebri1

mikey72 wrote: »

It's a stepper moter driven from the ecu nowadays, off a driveshaft or hub sensor.
It's normally set at -5%, +0%.
The design and construction covers anything on the road, and hasn't been updated since a spinning magnet and a spring loaded needle.

Yeah I fully understand how they work, most I've seen seem to work via the ecu from a gearbox final drive shaft sensor, but I have still yet to see any car, with standard wheels of course SG, that does not approach or exceed the 10% over read.

Travel regularly in the M1 50mph limits and you'll easily work out who's using the speedo and who the SatNav,

mikey72

cyclonebri1 wrote: »

Yeah I fully understand how they work, most I've seen seem to work via the ecu from a gearbox final drive shaft sensor, but I have still yet to see any car, with standard wheels of course SG, that does not approach or exceed the 10% over read.

Travel regularly in the M1 50mph limits and you'll easily work out who's using the speedo and who the SatNav,

It'll just be the BMW and Audi drivers that like to think they can drive at 70mph, so it makes sense to set their speedos to read high.
My vauxhall is still within a couple of mph at 50 or 70.

Maybe we should start a post on it, and see which cars have halfway decent speedos, or who's getting them from china now.

cyclonebri1

Probably not worth it but I can state that my Renault on it's factory wheels and tyres definately reads a constant and exact 10% over, ie, 55 at 50, and yes it is still working :rotfl:

Nearly_Old

mikey72 wrote: »

Maybe we should start a post on it, and see which cars have halfway decent speedos, or who's getting them from china now.

Would be interesting but not probably very pratical as SatNavs in themselves may not be 100% accurate 100% of the time then so when, where and how would you suggest that we do it?

Single speed using a fully calibrated speed gun?

Time through a measured 1/4, 1/2 or 1 mile?

Check at 40 / 60 / 80?

Like any calibration exercise unless the conditions are exactly the same for every item being tested then the the results would not be correct.

I have previously calibrated mine on a measured mile on a section of dual carriageway now superceded by motorway - it was originally set out for the police and was used by them for a number of years to calibrate their in-car equipment.

Bongles

SHIPSHAPE wrote: »

If he caused a 25 car pile up, guess what?

He would have caused it.

Stupid post.

It's not a stupid post.

Of course, if he causes the pile up, he caused it. But I don't know if I could live with myself if I learnt that the idiot whose frustration caused a pile up, killing and injuring other people, was the same idiot whose frustration I'd enjoyed deliberately adding to only a short time before.

Taking delight in winding other drivers up is deeply irresponsible.

mikey72

cyclonebri1 wrote: »

Probably not worth it but I can state that my Renault on it's factory wheels and tyres definately reads a constant and exact 10% over, ie, 55 at 50, and yes it is still working :rotfl:

I just took my 80's renault out, and put the sat nav in it.
Once the needle stops shaking, it's near enough 3mph faster on the sat nav than the speedo, for 30 to 60mph.

scooby75

Seems ive accidentally opened a little can of worms on accuracy. All I was trying to say on that point, bearing in mind mine is a digital readout, is that there will be some error, no matter what. You cannot have a totally accurate measuring device as it is impossible. The degree of accuracy is something different.

anotherbaldrick

If we are talking accuracy , the difference shown on a speedo is about 1.5% between a new set of tyres and those due for change.

SHIPSHAPE

Bongles wrote: »

It's not a stupid post.

Of course, if he causes the pile up, he caused it. But I don't know if I could live with myself if I learnt that the idiot whose frustration caused a pile up, killing and injuring other people, was the same idiot whose frustration I'd enjoyed deliberately adding to only a short time before.

Taking delight in winding other drivers up is deeply irresponsible.

Well, I'm not going to pull over to the middle lane whilst I am overtaking at 70mph just because some turd behind me wants to go about 80+mph thinking he owns the road flashing me like a burk and flapping his arms around like Orville on acid.

He'll have to wait until I have finished my overtaking and I am able to change to the middle lane.

If that winds him up them tough titty and I couldn't care less.

Bongles

SHIPSHAPE wrote: »

Well, I'm not going to pull over to the middle lane whilst I am overtaking at 70mph just because some turd behind me wants to go about 80+mph thinking he owns the road flashing me like a burk and flapping his arms around like Orville on acid.

Neither am I. I wouldn't suggest that you should.

SHIPSHAPE wrote: »

He'll have to wait until I have finished my overtaking and I am able to change to the middle lane.

Agreed. I wouldn't change lane any earlier or later than if he was waiting patiently behind at a safe following distance.

SHIPSHAPE wrote: »

If that winds him up them tough titty and I couldn't care less.

If I drive safely and considerately and someone gets wound up because of some mistaken belief that they're more important than me, that's their problem, not mine - there is little I can do about it. But their frustration is still a danger to others and I would want to review how I had interacted with them to see if their was anything I'd done that wasn't as safe or considerate as it should have been - in case I had perhaps, even inadvertently, made things worse.

But all this misses the point of my previous post. You said you love annoying them. That gave the impression that you would behave differently with a tailgater behind than with someone following safely, with the specific goal of further annoying the tailgater. That would imply a reckless disregard for the safety of others. I hope that's not what you meant.