Hello, i have recently purchased my first car, a Fiat Punto (pictured below). The car seems to be in perfect working order other than the speedo reading out.

We have tried gauging how much the speedo is incorrect by and it is reading about 5-8mph lower than the car is going (ie. if speedo say 50mph were going 58mph).

Can this be easily fixed (loose cable etc.) or does it mean i will have to continue to do calculations when going through a 30 speed zone?

Picture:

Cheers guys, ex site

all speedo's are inaccurate to one degree or another.have you checked the size of tyres? may be the wrong size of tyre has been fitted throwing out the readings.
what are you using to gauge your 'true' speed?

The alloys are standard (which came from the car new)

We have been gauging the speed by one of us driving this and the other in one of our other vehicles (mondeo and astra td), tried it today and above 50mph it reads 10mph less than its going (showing 60 and going 70 in reality).

When going 30 according the dodgy speedo its going 35mph in reality,

Can this be easily fixed, ie. resistance in the cable or is it major?

fiatpuntosx said:

The alloys are standard (which came from the car new)

We have been gauging the speed by one of us driving this and the other in one of our other vehicles (mondeo and astra td), tried it today and above 50mph it reads 10mph less than its going (showing 60 and going 70 in reality).

When going 30 according the dodgy speedo its going 35mph in reality,

Can this be easily fixed, ie. resistance in the cable or is it major?

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HI, other options for the speedo reading out include :-
1.the gearbox may have been changed in the past and the original final drive(diff) not kept.
2.wrong speedo drive gear.
3.different size tyres fitted compared to original (eg.155/70 r13 orig, 165/65 r13 fitted on the wheel) will have different circumferance despite being on the same wheel.
4.Fords and Vauxhall speedo's are notorious for reading over so try finding someone with a GPS unit as they tend to give a speed readout accurate to about 1% (helps if you travel at a constant speed for the accuracy) or go on the motorway at 60mph and time yourself between the mile markers which would take 60 seconds at a true 60mph.
hope this may give you some other options on your speedo reading.

ps. could also be the speedo FIAT use for their 0 - 60 figures which are always slower than in real life.

Cheers for the post, how do you know if your contain the unit to read accurate speeds?

We only have a Vauxhall or Ford, maybe i should take it down to the garage and get it checked out because it is very annoying!

Cheers, hope to hear back soon

TT

Do you know any one with a portable gps unit like the Garmin Quest or TomTom Go?

If so, you could use that to compare the actual speed (as measured by the gps) with your speedo.

Sorry for bringing up an old thread but it's the only one I found that describes my fault.

The speedometer shows around 10 kmh below the real speed. With more and more traffic cameras this presents an issue for me.

The car had a brake job last year but that's about it. The gearbox wasn't touched or changed, the wheels are stock size and nothing else was messed with.

The speedometer needle is consistent (-10 kmh), it doesn't jump or act unusually.

What could be the issue?