How Accurate is the Speedo

[nth]

e.g. Needle says 30 how fast will I be going? passed a few cams with the needle slightly above and no flash. . .
was next to a 57 civic and noticed they had a digital one, quite beneficial for cameras imo

 

[zack40]

dunno...but you want to try going through on my 30 year old bike.i s**t mi self every time i see i speed camera.the needles flicking very fast between 20mph and40 lol...but it does 200mph not bad for a old 125..hehe

 

[Mogzieno1]

Yeh, ive noticed similar things with my speedo, often compare it to the one on my satnav. Satnav usually has me going a couple of MPH slower.

 

[CHRISK172+]

Found mine around 3-5 mph out at 1**. I think its fair to say you'll be fine if you adhere to your speedo.

 

[Black-Clio-1.4]

Isn't the speedo driven from the gear box, therefore making it an estimate? But always says your doing higher than you actually are?

Satnav, should be correct as it's following you, and can actually measure your speed accuratly?

 

[scott7912]

My cruise control set at 70 the speedo says 72.
GPS says 70, my speedo 73.
RSTuner pro says 70, my speedo 72.
So id say at 70 mines about 2-3mph out.
At 30 i think you would be doing 30.

 

[jesus]

The needle is a bit below the actual speed you're going. Mine was slightly above 30 and one of those signs that tell you how fast you're going flashed up 28.

 

[Ali]

Last time when i was coming home late. 90 on speedo was 83 on cruise and 79.2 on my Pioneer HU! :S!!!!

 

[Poopensharten]

Speed cameras wont be set off unless you are doing 10% + 2 MPH over, this applies to all roads....

30 = 36
40 = 46

Im not saying the police wont pull you if they have a gun in hand but there far less likley to do you for 36 than 41-44.

 

[Hazza]

There is a headunit with a speedo reader on it???

 

[Scaggeh]

Speed cameras wont be set off unless you are doing 10% + 2 MPH over, this applies to all roads....

30 = 36
40 = 46

Im not saying the police wont pull you if they have a gun in hand but there far less likley to do you for 36 than 41-44.

Useful but I wouldnt live by it. Seen plenty of people with SP30s for doing 33 in a 30 etc. Depends on the calibration of each particular camera.

As for the original question, furthest out ive seen my speedo is 4mph (compared to GPS) at the higher end..

 

[Marky_]

I think it'd probably vary with each car.

I passed one of those electronic speed signs today at a steady 40. The sign read 36....

 

[Chris_Cliomk1]

Speed cameras wont be set off unless you are doing 10% + 2 MPH over, this applies to all roads....

30 = 36
40 = 46

Im not saying the police wont pull you if they have a gun in hand but there far less likley to do you for 36 than 41-44.

Well i got flashed doing 33 in a 30 an got 3 points for it!

 

[Aluco]

Speed cameras wont be set off unless you are doing 10% + 2 MPH over, this applies to all roads....

30 = 36
40 = 46

Im not saying the police wont pull you if they have a gun in hand but there far less likley to do you for 36 than 41-44.

since when is 10% of 30 +2 =36 ?

 

[Bulld0g]

I have been told that police allow 4% tolerance between thier mobile cameras, lasers etc for inaccuracy of the speedo.

 

[mattjk]

It used to be 10%+2 wheather it still is I am unsure.

 

[Reyes]

30 mph = 60mph imo