Speedo Acuracy????

[jaytip]

While out in the car yesterday i had my sat nav on,and i could not believe the difference in speed between the sat nav and the speedo.The sat nav was reading 73MPH while the speedo was reading 80.That's a huge difference :eek: Anybody else experiance this?
I don't think it's the sat nav that's wrong because i use it when i'm in the taxi and whatever taxi i'm driving(it could be one of five cars)the speedo is always within 1-2MPH.Strange.

Cheers,

Ivor.

[NoelWatson]

While out in the car yesterday i had my sat nav on,and i could not believe the difference in speed between the sat nav and the speedo.The sat nav was reading 73MPH while the speedo was reading 80.That's a huge difference :eek: Anybody else experiance this?
I don't think it's the sat nav that's wrong because i use it when i'm in the taxi and whatever taxi i'm driving(it could be one of five cars)the speedo is always within 1-2MPH.Strange.

Cheers,

Ivor.


Same with me

[Senninha]

Not as marked a difference for me, at 80 on Garmin, speedo was reading 84 which I didn't think was too bad

regards, Paul

[dan the man]

Every cars the same. Thats why u can getb away with 75 going past a copper easily on motorway. Ay 160MPH my DC5 was 155GPS as was very well calibtrated. At 50mph it was only 1 out!

[britlude]

same here, tho mine is a JDM with a kph/mph converter in line.. i though it was the convertor that was out of calibration! still, the legal requirement for a speedo is that it can overread by as much as it likes, but NOT underread!

[jaytip]

Every cars the same. Thats why u can getb away with 75 going past a copper easily on motorway. Ay 160MPH my DC5 was 155GPS as was very well calibtrated. At 50mph it was only 1 out!
I agree that all cars are a little bit out,but i think the NSX speedo (mine anyway) is very badly calibrated.As i mentioned in my first post,the taxis i drive are much more accurate.Very poor from Honda.

[Steveycaz]

Must vary a lot between cars then. My 91 is pretty much spot on up to 90 (any more than that and I'm not watching the speedo or the GPS :eek:)

[Silver Surfer]

My '91 is also spot on at any speed since I put on wider tyres all round.
Once showed 110 on Navman and speedo!!

SS

[NoelWatson]

I agree that all cars are a little bit out,but i think the NSX speedo (mine anyway) is very badly calibrated.As i mentioned in my first post,the taxis i drive are much more accurate.Very poor from Honda.

It doesn't get worse as apeeds increase (at least one mine). At Bruntingthorpe, 170 on speedo was 162 on GPS

[NSXGB]

My speedo reads 3-4 mph more than the TomTom throughout.

Jaytip, I presume you are running the correct size tyres?