Inaccurate Speedo

[patbhoy]

I think the speedo on my Trol is reading out by around approx 7mph, is there any way of calibrating it.

 

[zippy656]

bigger wheels

 

[briggie]

mine under reads by between 5 and 7 mph .... so i need smaller wheels ? :augie

 

[larson]

mine is also out so i use a tom tom to see what my speedo says at 30/40/50 and never had it to seventy yet

larson

 

[briggie]

my solution is less technical ... i know that if my speedo is reading 25 mph .... im really doing 30 , if it reads 40 mph , im doing 45mph ish

 

[patbhoy]

Like briggie mine is under reading, 70mph on the speedo is 63mph on tomtom.
My truck is running the standard 16" alloys fitted from new so why do i have this prob.

 

[makeitfit]

Seems to be common across the range :nenau
Mine was the same but now running 33s and it's spot on:thumbs
I guess the gearing must have been designed for diff size wheels or something:augie

 

[Thomas-the-Terrano2]

been here before its certainly a nissan thing but suspect all makes under read
to protect your licence, its about 10% all the way.

i use to my advantage, as good cruising speed is 65 on gauge, so actually
about 60, so can speed with van and still be legal, keeping ahead of everyone
else that is believing their speedos lol.

 

[briggie]

Like briggie mine is under reading, 70mph on the speedo is 63mph on tomtom.
My truck is running the standard 16" alloys fitted from new so why do i have this prob.

no pat , my speedo says 25 mph when im actually doing 30 mph according to my sat nav

 

[(RIP) PLANK]

mine is the same it says i'm going faster than i am going acording to tom tom

 

[briggie]

mine is the same it says i'm going faster than i am going acording to tom tom

mine is the reverse of that ..... it says im going slower than i actually am

 

[makeitfit]

Ah, you need smaller wheels on your sat nav :lol

 

[danielj]

Check my speedo against those electronic speed signs on the side of the road which flash up your speed. Mine is about 10klm/p/h high (speedo says about 60 when sign says about 50).

 

[briggie]

Ah, you need smaller wheels on your sat nav :lol

would larger wheels on the car work ? :nenau

 

[(RIP) PLANK]

mine is the reverse of that ..... it says im going slower than i actually am

that is a worry!

 

[danielj]

would larger wheels on the car work ? :nenau

They probably would work as long as they are round but they wouldn't help your speedo problem much :lol

 

[briggie]

my sat nav is one of those garmin thingies , that beeps at you continuously if you are over the speed limit or if a speed camera is near, , its great , but can be bluddie annoying :augie

 

[makeitfit]

Mine's garmin, but on my phone
Set the speed camera alert to bleep twice then shut up, big speed limit sign stays on though:doh

 

[macabethiel]

speedo cure

You can get a speedo for a push bike and fit it to your truck quite easily and you can adjust the calibration for your actual measured wheel rotation in m.m.

A bit of a bracket to hold the sensor in place and you are sorted. Its easier on a motor cycle as you can attach the pick up to your forks.

Not ideal for off-roading as the mud would soon bugger it up.

On a car you need to fix a bracket for the pick up onto the front strut and the magnet onto your inside wheel with some double side tape or Tiger Seal.

On my Yahaha XJ 900 it was accurate to well over a ton !

You can get a basic unit for less than £10 and a wireless one for less than £30 !

Not as likely a target for thieves as a satnav if you leave it in place.

 

[Thomas-the-Terrano2]

suspect an under reading speedo is illegal as allowing you to speed when
you think at or under given limit.

smaller wheels if anything, as normally over reading speedo is corrected by
modestly over sized tyres.

mind its a mistral isnt it, are you reading the km/h , then again as 50mph
=80km/h that would be unlikely.

i would use sat nav, but also cross ref it against those active speed signs.

think your odometer could be in km too, all this could be stuffing your
mpg calculations too.