seen on here many times some members banging the drum that the speed your speedo displays and the digi tacho are not showing you ‘actual speed’
so could some answer my question then, if i am driving along, lalalalalalalalalala on the limiter, digital speedo says 56mph and digi says 90kph, i go past one of those interactive signs and it says YOU SPEED 56MPH. why is my speed not correct then?? if 3 different instuments show the same speed i dont understand how i can be going slower?
dont police use them same sort of technology as those signs??
just confused really people, just dont get it how your speed is slow than what is displayed, if so how do you actually find out your ‘true speed’
Some vehicles do show the incorrect speed on their speedo, a sat nav should tell you your true speed as that works your speed out using the distance divided by time formula, the speedo uses a sensor or cable linked to the gearbox, if you have bald tires compared to brand new ones then that will make a a difference between your actual speed and whats shown on the dash. Your digi tacho will always show exactly the same speed as the dash speedo as they are linked together.
groovy greg:
so could some answer my question then, if i am driving along, lalalalalalalalalala on the limiter, digital speedo says 56mph and digi says 90kph, i go past one of those interactive signs and it says YOU SPEED 56MPH. why is my speed not correct then?? if 3 different instuments show the same speed i dont understand how i can be going slower?
A lot of those signs are not actually speed sensitive, but they are movement sensitive. There’s one in particular, on the A47 at Middleton just east of Kings Lynn, that flashes up 40 mph, even when you’re doing 35mph!
bubsy06:
. Your digi tacho will always show exactly the same speed as the dash speedo as they are linked together.
i would have thought that the speed they were displaying was spot on & just as accurate or more so than a sat nav as a hgv speedo/tacho has to be calibrated ever 6 years to ensure it is giving the correct reading as it’s marked down on a chart that is admissable in a court of law.
not much point in having a tacho head or digi tacho if it’s not giving the right speed for your vehicle,surely that’s a major part of it’s job
bubsy06:
. Your digi tacho will always show exactly the same speed as the dash speedo as they are linked together.
i would have thought that the speed they were displaying was spot on & just as accurate or more so than a sat nav as a hgv speedo/tacho has to be calibrated ever 6 years to ensure it is giving the correct reading as it’s marked down on a chart that is admissable in a court of law.
not much point in having a tacho head or digi tacho if it’s not giving the right speed for your vehicle,surely that’s a major part of it’s job
Its mainly down to the tyre condition, worn tyres are smaller than new tyres, think of a bmx bike compared to a mountain bike, if both people peddled at the same speed then the mountain bike would end up covering more distance because of the size of the wheels. The truck speedo reads the speed from the gearbox not the wheels, so when doing 40mph with new tyres you will cover more distance than when doing 40mph with worn tyres, thats why people try to get there truck calibrated with worn tyres, the engine will be set for a max of 56mph, the truck owner will then go and put brand new tyres on and that will increase the actual speed of the truck. Actual speed is worked out by distance divided by time not by a sensor stuck in a gearbox. Hope that makes some sense
Im same, 90kmh on digi head, 55mph on sat nav, been passed a few RENAULT PREMIUMS that have the SPEED DISPLAY on dash reading 56mph and I toodle past SOME no bother, so a bit more quicker and some go past me like hell… All been passed Civic (New shape) again with digi display that shows speed and the Civic was reading 58mph :=O
scottishcruiser:
Im same, 90kmh on digi head, 55mph on sat nav, been passed a few RENAULT PREMIUMS that have the SPEED DISPLAY on dash reading 56mph and I toodle past SOME no bother, so a bit more quicker and some go past me like hell… All been passed Civic (New shape) again with digi display that shows speed and the Civic was reading 58mph :=O
I was passing one of those Citroen ‘I need my fanny sewn up cos I have to many kids’ Picasso’s, or it might have been one of those Citroen Picasso Ive got an ingrowing toenail so cant work and get a free car on disability Special Editions, anyway it was reading 5mph more than I was doing and I was overtaking
Yip done the exact same Bubsy… Maybe the only way to get a true reading would be to get stopped by the cops lol■■? Even then youd argue the point that not 2 things are telling you the 1 speed.
i was driving an 08 plate man wagon and drag…the tacho and speedo read 89kph…56mph.but i was not keeping up with the traffic,tesco trucks were difficult to pass…so i checked it against my gps…at a read 89kph i was only doing 84kph…52mph…the rear tyres were 2 years old and well worn.
they fitted 4 new tyres across the back for the mot and it was doing a true 56mph…for 2 weeks…then they shut the limiters down to 85kph!!!
i know a bloke who runs his own trucks that has a set of well worn tyres he fits just before the tacho calibration…then refits his new tyres right after…it gives him the edge on speed…but i guess the feul economy sufferes?..depends what matters most?
why worry about it lads as most of you are hourly paid, slower the better surely, the truck i drive has a sticker saying limiter set at 89kph the truck and digi are saying 90kph and the sat nav 87kph, and i get to were im going at that speed ( which ever is true )…
