Just wondering how far out everyone thinks there speedos are???

I've had my speedo saying 115mph before which is great except the car has an apparent top speed of 93mph (only got a K&N fitted).

I know from a tom tom that when the speedo says 80 i'm really doing 70 and it gets worse as u get faster!!!

Good old Fiat build quality and accuracy.

Rob

all car speedos are inaccurate, they test to be most accurate at 50mph and the further away from that spped you get the worse they are usually. i also use my sat nav with tomtom to get a more accurate figure, my girlfriend's mk2 punto sporting is actually doing about 100mph when it says 112-115mph. my bravo hlx is actually doing 110mph when it says 130mph, but i think thats partly to do with my lower tyre profile as well as natural inaccuracies.

its normal to have inaccurate speedos, the needle is balanced against a spring, springs follow hooke's law where k is a constant which is needed to predict the springs behaviour, but hooke's law is only accurate in theory, in practice the spring will not have a perfect rate of change of force as expected with hooke's law, also springs will lose some force over time meaning an old or high milage speedo will read differently to a newer one. also gps isnt perfectly accurate, if you travel in a perfectly straight line at a constant speed they are very accurate, but in other situations they cant be relied upon.

Oh yeah i know that all speedos are inaccurate mine just seems excessive compared to other cars i've tried.
My mates pug 306 was 2 mph out at 80 and my old mans volvo 850 was 3 at 80mph.

Fiats just seem a little worse. lol

Rob

Other factors such as larger wheels can also contribute to an inaccurate reading.

Im currently 5mph out

OT warning.....

jug: loving your avatar dude! everyone loves tidy trax :worship:

Well i've had mine reading 117mph, no mods except drilled standard airbox (makes no difference apart from noise as far as i can tell) and we all know thats gotta be way off. Its no biggy though, feels like 117mph in a cento i can tell thee.