Innacurate Speedo????

[PoorMansPorsche 0]

Alrighty peeps

 

ive just noticed that when i use my sat nav, my speedo is showing that im actually 2 to 3 mph faster than the speedo on the sat nav. I take it this is VW covering themselves etc, but do they actually use timing devices when testing 0 - 60 times or do they use the speedo because this would mean that published times would actually faster than in reality if they went on the speedo??? it doesnt matter because all things are relative because i take it all manufacturers do this as my corsa van is 7mph out at 75mph !!!

 

brett

[Supercharged 2]

Yep, thats correct they have to overread, also depends on what size wheels you are running (if the rolling radius is different from standard)

[davidwort 0]

Alrighty peeps

 

ive just noticed that when i use my sat nav, my speedo is showing that im actually 2 to 3 mph faster than the speedo on the sat nav. I take it this is VW covering themselves etc, but do they actually use timing devices when testing 0 - 60 times or do they use the speedo because this would mean that published times would actually faster than in reality if they went on the speedo??? it doesnt matter because all things are relative because i take it all manufacturers do this as my corsa van is 7mph out at 75mph !!!

 

brett

 

Standard wheel size on my 16v (half worn tyres) and it reads nearly 35 at 30mph (travelling towards one of those flashing speedo signs).

 

David.