Altea Speedo Accuracy

[altea-ego]

When driving my Altea, I can't believe how slow some speeds seem compared to my previous car. Even in the demonstrator I felt this too.

Anyway, I now have the explanation. The speedo overreads by 10%. I know this because I have bought some diagnostic kit which reads live data from the ECU. When the speedo reads 40mph the ECU is reading 36mph. And when the ECU reads 40mph the speedo reads 44mph.

This is with brand new tyres, so you can imagine when the tyres are low it will over read by more than 10% which will be illegal. I think Seat have set it up on the side of caution. At least I now know I can go faster and still be legal

 

[Tell]

I feel better about doing a 100 now since it's only 90....

 

[big ALI H]

Wouldn't be too sure mate. Try using some GPS equipment to compare against your speedo. I know in my Ibiza and my old Leon, the speedo was about 98% accurate.

 

[Redcupra20vt]

according to my road angel 2 in my MK3 Ibiza cupra, the speedo is out.

Paul

 

[Yello]

My Leon Cupra R speedo was also in need of re-algnment.

I have an OriginB2 and the GPS confirmed on the Leon that it was about 5% out increasing though the faster you went. I haven't yet fitted the Origin to the Altea as the nearest power source (Ciggi Lighter) is placed too far away rather than under the dash as in the Leon. I may have to hardwire it in, but need a scematics from someone if they have it...?

 

[mr_claypole]

same with my LCR... road angel say 90, you're actually reading 100+ on the speedo...

eek.

 

[ALT54]

My Altea speedo is also approx 10% out when checked against my Road Angel and Navman sat Nav.(Both read exactly the same GPS speed)
Our Alhambra on the other hand is only a couple of percent out.
My Vrs Octavia also used to be out by about 10%
Paul

 

[CrispDust]

Indeed I checked my Altea today - overreads by at least 5-6 mph at 80.

 

[muddyboots]

Speedos are allowed to over-read by a certain percentage, but they're not allowed to under-read at all.
So the manufacturers tend to err on the side of caution

 

[Rallye Dale]

Our's over reads about 5 - 6 mph when compared to TomTom Satnav

My 03 plate Caddy over reads by about 4 mph

 

[FR+TDI]

As mentioned in another thread, my 17" wheel equipped 55 plate TDI Sport now wears 235/45-17 tyres instead of 225/45-17, I initially did this to try & reduce the quite harsh ride at lower speeds (wider tyre with same aspect ratio = higher side wall = softer ride). I also had a Road Angel and with the 225's it was 7mph high at 70mph, but with the 235's its only 3mph high at a 70mph and 1mph high at 30mph. Ride quality has also improved just enough to make the change worthwhile with no noticable effect on handling, also with the tyres being 10mm wider, I have better rim protection .

 

[Redcupra20vt]

As mentioned in another thread, my 17" wheel equipped 55 plate TDI Sport now wears 235/45-17 tyres instead of 225/45-17, I initially did this to try & reduce the quite harsh ride at lower speeds (wider tyre with same aspect ratio = higher side wall = softer ride). I also had a Road Angel and with the 225's it was 7mph high at 70mph, but with the 235's its only 3mph high at a 70mph and 1mph high at 30mph. Ride quality has also improved just enough to make the change worthwhile with no noticable effect on handling, also with the tyres being 10mm wider, I have better rim protection .

are you saying on the 225 tyres, when the speedo said 70 the road angel said 77?

paul

 

[dlm2310]

are you saying on the 225 tyres, when the speedo said 70 the road angel said 77?

paul

That reads to me as Road Angel 70, speedo 63.

??

 

[PaulieB]

I believe a lot of the newer cars are delibretly out on the speedos. I know for a fact the Corsa is out by 10% as the driving instructor had 2 speedos, the one on the passenger side was correct, the drivers side wasn't i believe it was an agreement between a few car manufacturers to get people to slow down a bit without them realising.

 

[FR+TDI]

That reads to me as Road Angel 70, speedo 63.

??

Sorry if I've confused anyone. Speedo was reading high (as they all are). Speedo was on 70, car actually doing 63 on GPS with 225 tyres, now on the 235's speedo reads 70, car actually doing 67.

 

[Tell]

Is it not that the manufactures of cars don't want to be done by private claims and insurance companies for accidents and deaths due to people speeding above indicated speeds so they error down on the equipment. Honest John goes on about centre lane cruisers and inaccurate speedos on a regular basis - lorries having the accurate ones hence why they 'chase' you in motorway maintenance areas since they are going at the correct speed.