Speedometer Calibration Required?

[Crawf]

Just upgraded from the stock 17's to some new 19's , do I need to get my speedo calibrated to read correctly?

 

[PaulSV6]

Yes u will, as the rolling diameter of the wheels has increased.

 

[Jesterarts]

No, provided the correct tyres are fitted.

 

[Jonesy484]

Yes u will, as the rolling diameter of the wheels has increased.

No he will just need to get low profile tyre. 245.35 R19 should do

 

[Crawf]

Thanks for the info, I have 245.35 R19 on so sounds like i should be alright, may check to see how much a calibration would cost anyway because most of the time my digital display and needle speedo read differently. Cheers

 

[88GreenVN]

The PPK number will need to be changed for the speedo to be spot on if you have changed the overall size of the wheel (how tall it is)

 

[Jesterarts]

Far out people, why to try and confuse the bloke.

The PPK only needs to be updated if the overall rolling diameter is changed beyond the legal increase tolerances.

From memory the increase is 15mm increase to the overall rolling diameter.

With the fitment of the correct tyre size, the OP will not needs to worry about getting the speedo calibrated.

Changing the PPK will also not change the discrepancy between the needle on the guage and the digital speedo.

Based on my calculations, the tyre the OP has used will cause the speedo to show about 1.7kmph slower than he is actually travelling but considering the speedo from factory has a 3kmph odd tolerance he's all good.

 

[nathanVY]

Jest is spot on.

The correct tyre profile, will not alter the speedo by more than about 2% at most...


The correct tyre profile for 19s on a VZ i 245/35/19 - will need to comply with the load rating on your car as well which should be around 93.

 

[showbags]

I've got 20's on mine and speedo's still spot on.

 

[Mavericks Choice]

Jest is correct, if your really concerned have a mate observe your speed using a GPS whilst holding your car @ a set speed, done mine when going from 16" wheels to 18" & no problems.