speedo accuracy

[don simon]

I put a speed app onto the phone today as I wanted to check car speedo vs real speed, and guess what?
Car................App
35................. 30
47................. 40
59.................. 50

Are they all this far out?

 

[terranosaurusdoug]

Does it stick sometimes?

 

[Monty]

I put a speed app onto the phone today as I wanted to check car speedo vs real speed, and guess what?
Car................App
35................. 30
47................. 40
59.................. 50

Are they all this far out?

Mine 2003 3lt just about the same via satnav

 

[don simon]

No, it runs normally. The only reason I downloaded the app was because those horrible signs that flash up your speed with a frowny face didn't agree with my speedo. Otherwise it looks normal.

 

[terranosaurusdoug]

Usually speedos show 3mph faster than what you are doing, mine is waaay out, speedo sticks after a while and on long journeys rev counter sticks too! Apparently a common thing, I'm going to try a repair I read Anouilh on here, if it does I was thinking about posting a how to guide.

Just thought, have you got standard size wheels n tyres?
Mark.

 

[The Patrolman]

I've got a spare little black box I bought from Aus.
It sits in line between the gearbox and the speedo you can dial in + - 100% to calibrate your speedo to your liking.
On the other side of this you are putting 10% extra mileage on the clock too
I bought mine to fool the gearbox into changing up earlier due to the new tyre size.

 

[solarman216]

by law the vehicle manufacturer is allowed to let the speedo over read but must not let it under-read, I guess the penalty for doing so is high so so they make sure they are safe by high over read and if this applies to the odometer as well then look what that does for consumption figures, I am running 31's and that puts my speedo spot on, Rick

 

[Sweety]

They all over read:augie at 60 on the speedo my satnav's show 55 only way to fix it is to fit larger tyres but the over reading has saved my bacon a couple of times in hidden speed traps:augie

 

[terranosaurusdoug]

I've got a spare little black box I bought from Aus.
It sits in line between the gearbox and the speedo you can dial in + - 100% to calibrate your speedo to your liking.
On the other side of this you are putting 10% extra mileage on the clock too
I bought mine to fool the gearbox into changing up earlier due to the new tyre size.

Yeh did some research into that once, I think it was j-car I found

 

[johnb5177]

Mine 2003 3lt just about the same via satnav

+1.......:nenau

But at least I don`t get happy snapped by speed cameras.....:nenau

 

[perelaar]

My speedo is well off. In km/h (I live in Belgium) about a 10km/h difference between speedo and real speed verified with GPS.

Difference gets bigger the faster I drive. Example: 60mph, about 100km/h, reads as 66 mph (110km/h).

 

[terranosaurusdoug]

It was jay-car :thumb2

https://m.youtube.com/watch?v=bMs7w72QTVM

 

[nemofish2000]

by law the vehicle manufacturer is allowed to let the speedo over read but must not let it under-read, I guess the penalty for doing so is high so so they make sure they are safe by high over read and if this applies to the odometer as well then look what that does for consumption figures, I am running 31's and that puts my speedo spot on, Rick

That's what the guy said when I had to attend a speed awareness course..ooops

 

[jims-terrano]

Ive yet to drive a car that does read correct speed:nenau

Personally I go by the car speedo and then I know I'm less likely to get a ticket.

 

[Sweety]

Ive yet to drive a car that does read correct speed:nenau
.

My 02 plate Astra Coupe was only 1-2mph out:thumbs I blame vauxhall dodgy electric's for this:lol

 

[rustic]

My Skoda Yeti with it's VW built 1.6 diesel engine says at 80 mph it's doing 100 mpg lol.... with no emissions of any sort lol....
:lol:lol

Skoda say they will soon have a fix that will bring the Nox levels down...
They say...:augie it won't affect the performance of the car in any way.:lol:lol
Moderators feel free to put this in the jokes section lol....:lol:lol

Yeah right... if this fix works... then why wasn't it incorporated into the car when built...?:nenau

So I'm waiting for a few other mugs to have this mod before I have to have it.

So most car manufacturers exaggerate the performance in one way or another.
My mav, with upgraded 235 75 R15 is basically spot on vs the sat nav on a straight line run, and that is important.
Pity we can't adjust them.

When our kids were learning to drive with the fiesta, I never told either of them that it was about 15% optimistic, so they never got a ticket whilst we had that car, so as said, can be usefull.
What is annoying, is if you get behind a car like that, and you know you could just maybe push your limit to a few % over the actual speed limit, then you could be travelling at 10 mph more, then you "could" just scrape through.
Then again.... you could be going on a speed awareness course. Most people that have attended these are only a few mph over the limit.:nenau

 

[rayf3262]

My Skoda speedometer over reads quite significantly too.
Phone, GPS both indicate the same lower speed.
Interestingly the Skoda diagnostics agree with the Phone and GPS, so I conclude speedometer over read is by design!
On the plus side your vehicle has probably done around 10% less than the actual recorded mileage.

 

[don simon]

My Skoda speedometer over reads quite significantly too.

I'm surprised that a Skoda overreads....

 

[rustic]

I'm surprised that a Skoda overreads....

It shows 50mph and you are doing approx 47mph

70 mph and you are doing about 67 mph.

 

[don simon]

It shows 50mph and you are doing approx 47mph

70 mph and you are doing about 67 mph.

But their emissions.............? :doh