Your speedo accuracy

obi_waynne

Administrator
Staff member
Moderator
Points
1,137
Location
Deal, Kent UK
Car
A3 1.4 TFSI 150 COD
How accurate is your speedo?

Comparing mine with a sat nav I see an indicated 60mph when the sat nav shows I'm doing 59 - in my book that is pretty accurate.
 

SLEEPER

Pro Tuner
Points
552
Usually clocks are out by a bit . My caldina over reads by 8 to 9 %. The stagea however is spot on even correct at 170 mph confirmed by v box at Marham airfield runway during timed 30-130 runs.
 

MADRod

Road Burner
Points
192
Car
Sierra RS Cosworth
I have a calibrated stack speedo. During Topspeed runs it was reading 3mph slow at 210mph.

 

Yugguy

Torque King
Points
507
Location
Rugby (expat Preston lad)
Car
Merc C220Cdi Elegan
Mine shows 32 when I'm doing 29 but 75 when I'm doing 70 so the error increases a bit with speed.

Do very modern cars have speedos that link to the GPS signal for the built-in satnav? That would make sense to me to use both gps and the internal road speed sensor to get a more correct reading.
 

HDi fun

TC ModFather
Points
637
Location
Buckinghamshire UK
Car
Passat 2.0 TDi
Speedometers are often 'driven' from one or more ABS sensors. They're nearly all electronic now, the old days of a rotating Bowden cable into the back of the instument panel are long gone.
 

TCJBOLDIE

Moderator
Staff member
Points
667
Location
Brisbane
Car
2011 Honda FN2
My 4x4 reads 107 kph @ a sat nav 100 on a flat straight highway and the Starion with a RX7 box speedo 100 = actual 105
 

SLEEPER

Pro Tuner
Points
552
How did you manage to verify it's accuracy at 170mph whilst carrying out 30-130 runs?
The event was for 30-130 using supplied v boxes.
The runway was over a mile long and the v box doesn't turn off at 130.
So everyone had their top speed recorded as well. The runway surface is said to be the best in the UK (very special ashfelt ) and it is about 80 metres wide . On a well set up stable car it is pretty easy to see the speedo.
The top speed on the flying mile was 239 in a seriously tuned GTR whichdid the 30-130 in an equally insane 4.6 seconds.
 
Similar threads
Thread starter Title Forum Replies Date
old-git Can you help in identifying this speedo? General car Chat 10
D escort rs speedo problem General car Chat 2

Similar threads

Top