Doing a lot of driving back and forth through average speed cam areas on the A1 at the mo and my Tom Tom reads 39/40 when the car's speedo says 43/44with increased differences at 50 and 70mph (about 5-6 mph difference at 70). Is the GTR speedo over-reading - if so why is such a precisely engineered car giving a wrong reading?
Over-reading speedo?
1 - 20 of 24 Posts
All cars deliberately over-read the speed you are travelling. There are a few reasons for this, but 4% is typical.
By law, a speedo is allowed to over-read by as much as 10%, but NEVER under-read.
So if your actual speed is 40mph, your speedo can display anywhere between 40 and 44mph to be within the legal limit.
A display of 39mph would be illegal though.
By law, a speedo is allowed to over-read by as much as 10%, but NEVER under-read.
So if your actual speed is 40mph, your speedo can display anywhere between 40 and 44mph to be within the legal limit.
A display of 39mph would be illegal though.
Joined
·
7,641 Posts
Jesus, what next..??
Are you going to check whether the air out of the aircon unit is exactly at the temp displayed??
Every car's speedo is around 10% out, erring on the side of caution. Why on earth does it matter?
Of all the things in life to worry about, this has to be the height of nit-picking.
I'm off to check that if my tyres are actually 285 cm wide........
Are you going to check whether the air out of the aircon unit is exactly at the temp displayed??
Every car's speedo is around 10% out, erring on the side of caution. Why on earth does it matter?
Of all the things in life to worry about, this has to be the height of nit-picking.
I'm off to check that if my tyres are actually 285 cm wide........
If the speedo is linked to the odometer, my speedo is 6% out. Which means that when I've done 12,000 miles at the end of this year which I will, I have actually only done 11,280 so additional milage which I haven't done.
Joined
·
7,641 Posts
You really have nothing else to worry about?!
Think about it....
Every car has a speedo error of up to 10%. Therefore your concern applies to EVERY car on the road, not just yours. All things equal etc...
What difference in resale value does that 6% actually equate to?
Sorry if I seemed harsh in my previous post, but I am really getting fed up of some of the petty whinges people are now posting.
Frankly it's getting ridiculous.
Joined
·
535 Posts
Just like the Rust Thread :blahblah: youd think people had not owned cars before the GTR 
and that No other car has any problems :chairshot
Ive been on other Forums where the Replacement car gets a bashing e.g. Evo 1X gets a bashing from the other Evo owners + other forums :blahblah: You know the Replacement has gone soft type comments and the engine isnt as good :blahblah: But the knocking the R35 GTR appears to be getting is bordering extreme, I guess like all those other Model updates / replacements of Evos / Scooby etc etc etc the knocking will eventually die a death and those that Love the R35 GTR will continue to do so and those that dont will stick with the models that its replaced or move onto another Marque
and that No other car has any problems :chairshotIve been on other Forums where the Replacement car gets a bashing e.g. Evo 1X gets a bashing from the other Evo owners + other forums :blahblah: You know the Replacement has gone soft type comments and the engine isnt as good :blahblah: But the knocking the R35 GTR appears to be getting is bordering extreme, I guess like all those other Model updates / replacements of Evos / Scooby etc etc etc the knocking will eventually die a death and those that Love the R35 GTR will continue to do so and those that dont will stick with the models that its replaced or move onto another Marque
Just to be clear, my comments were not a dig specifically at the GTR! I'm fully aware of the fact that speedo's normally over-read. Some more than others. If the HPC can re-calibrate it fine. If not no big deal. For me I just like to see an accurate speedo readout and not have to second guess it, especially when going out for a spirited drive
I agree, too may petty whinges on this site, but none of them has come from me. If the speedo cannot be re-calibrated, fine. I'll still be enjoying my car every day!
Joined
·
7,641 Posts
Then fit a GPS device, as every car you've ever owned, and ever will, will be up to 10% under.
And that's the point isnt it? If you're out for a spirited drive, your speedo's indicated speed will always be less than your actual speed so you'll always be on the right side of the limit.
Again, I see nothing at all for anyone be remotely concerned about....
Joined
·
979 Posts
Ive always thought about this, over reading speedo's mean more mileage surely
Joined
·
1,537 Posts
Yep, means they get out of warranty period up to 10% quickerIve always thought about this, over reading speedo's mean more mileage surely
Joined
·
7,641 Posts
In reality it shouldnt because in modern cars the ECU gets distance info in a truer form from the drivetrain, then converts that to a speed for the speedo.Ive always thought about this, over reading speedo's mean more mileage surely
As such, whilst the speed calculation will have a +ve error, the distance travelled should be a more true value, as best it can taking into account tyre wear.
But like I said above, every car exhibits this error so it is fairly equal for every car on the road.
Joined
·
3,574 Posts
Most GTR´s are out off warranty in the first 5000miles....
Joined
·
315 Posts
CC............you must have a different spec car to most of us on here? Can you confirm your tyres are 2.85 metres wide?
They must grip like hell!!!
Joined
·
7,641 Posts
CC............you must have a different spec car to most of us on here? Can you confirm your tyres are 2.85 metres wide?
They must grip like hell!!!
ha ha ha ha!!!! What a crackin' typo!
well spotted!
Joined
·
765 Posts
LOL!.
Joined
·
765 Posts
Even bigger LOL!.CC............you must have a different spec car to most of us on here? Can you confirm your tyres are 2.85 metres wide?
They must grip like hell!!!
1 - 20 of 24 Posts
Join the discussion
