Wheels upgrade - speedo

[Smashfist]

Same goes when changing diff ratios, the speedo will not be accurate unless recalibrated.

VE and VF use the wheel speed sensors for speedo, so diff ratios can be changed freely without having to worry about the speedo.

 

[panhead]

VE and VF use the wheel speed sensors for speedo, so diff ratios can be changed freely without having to worry about the speedo.

Thanks mate, I've learnt something today.



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[Hyperduc]

+1

 

[VS 5.0]

As have I.

 

[cashie]

You’re speedo will be reading wrong from the manufacturer as almost all manufacturers intentionally build in an error where they read from 3 to 5 kilometres over the actual speed at about 100km/h.

It has often been said the reason is to ensure that drivers are under the speed limit so no class action can be taken against the manufacturer for speeding infringements.

This can make more sense when another factor comes into play and that is the wearing of tyres will cause the speedo reading to change, as will over inflation and the fitting of new tyres.

Deliberately calibrating the speedo to run high makes up for some of these fluctuations without the manufacturer running the risk of the vehicle actually travelling faster than the speedo reading.

Stick as closely as possible to the original diameter and you should be ok.

Changing the rim/tyre package's overall diameter will of course alter the speedo reading so if you have worries then use a GPS or have the speedo recalibrated.

Or change the tyres to a lower profile as the smaller overall diameter will cause the speedo to read higher than the true speed.

Same goes when changing diff ratios, the speedo will not be accurate unless recalibrated.

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The ADR speedo tolerance used to be (may still be) +10% -0%

 

[Ron Burgundy]

as long as the front to rear difference dosnt trip an error, they have a zero tolerance from factory unless u have factory staggered then there is a error value between front to rear that it has to be within, 4% fast is pretty normal, my VE is 2-3% most others vehicles can be 5-10% especially 4wd's

Front to rear difference should be fine..but i am not 100% sure.

Has anyone put staggered redline wheels on non redline ? Did it trigger any errors ?

 

[Ron Burgundy]

Here....

Small difference...

 

[Sean880]

Front to rear difference should be fine..but i am not 100% sure.

Has anyone put staggered redline wheels on non redline ? Did it trigger any errors ?

If you are going to run front tyres 245 40 19 (diameter 679 mm) and rear tyres 275 35 19 (diameter 675 mm) you definitely won't have any faults triggering because the minor difference between the front and rear tyre diameters is far too small.

It's much the same if you want to run 20 inch wheels and tyres (as many also do) with a 245 and 275 staggered set -
Front 245 35 20 680 mm diameter
Rear 275 30 20 674 mm diameter

This won't trigger any issues either because the differences in diameter are also way too small.

You won't have any issue with speedo accuracy either because the stock 245 45 18 tyres you have now are 677mm in diameter when new .

 

[07GTS]

Front to rear difference should be fine..but i am not 100% sure.

Has anyone put staggered redline wheels on non redline ? Did it trigger any errors ?

because the HSV have staggered wheels they have an error margin in the tyre rev per km front to rear but if u had same front to rear then the error is zero so if u have had a tune then just get the tuner to add some error room into so it dosnt trigger a code, just work out the difference in rev/per km and make the error just over that

 

[vc commodore]

You’re speedo will be reading wrong from the manufacturer as almost all manufacturers intentionally build in an error where they read from 3 to 5 kilometres over the actual speed at about 100km/h.

It has often been said the reason is to ensure that drivers are under the speed limit so no class action can be taken against the manufacturer for speeding infringements.





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This makes no sense....You are saying the manufacturer is building in an error whereby the car is travelling faster than the speedo shows, but then you say it saves a class action against the manuacturer for speeding infringements because it ensures you are travelling under the speed limit...You can't be travelling under the speed limit if the speedo is going slower than your actual road speed