Americas speedo off... what about odometer?

[TanisIndependentTraders]

okay so my speedometer is off by about 2.5 mph. Could this bad calibration also impact the odometer and thereby the range guess-o-meter?

 

[bigleonski]

okay so my speedometer is off by about 2.5 mph. Could this bad calibration also impact the odometer and thereby the range guess-o-meter?

I'm not sure what the story is in the States, but as far as I know everywhere else the speedo is always higher than real speed checked via a gps.

My gren reads 105km/hr when the GPS speed is 100km/hr. This was exactly the same on every 4wd/car I have had before it. Toyota's tend to be 104km v 100km. Legislated in Australia, conservative margin for error.

With 33" tyres my speedos have read 100 v 100 in the past.

 

[Jack123]

I'm not sure what the story is in the States, but as far as I know everywhere else the speedo is always higher than real speed checked via a gps.

My gren reads 105km/hr when the GPS speed is 100km/hr. This was exactly the same on every 4wd/car I have had before it. Toyota's tend to be 104km v 100km. Legislated in Australia, conservative margin for error.

With 33" tyres my speedos have read 100 v 100 in the past.

Yes there is a gap. Mine though is only a mile off - 75mph vs 76mph...

 

[Asnes]

My speedometer reads about 3-4% higher speed than I track on GPS. US Build.

 

[AngusMacG]

I have noticed that at lower speeds (<45 mph) the difference is about 1-2 mph while at highway speeds (55-85 mph) it is 3 mph off based on GPS speed

 

[AWo]

Up to 10% difference between the real speed and the odometer is normal and no point to worry, as long as the odometer is higher.

When you compare it to GPS drive on even ground.

AWo

 

[DaveB]

Vehicle manufacturers have done this for years to avoid lawsuits.
Frome memory US manufacturers GM & Ford were intentionally reading 5-6% high on the speedo.

 

[wolftimj]

It saves on the speeding tickets.

 

[Krabby]

But getting back to the OP - does this built in difference affect the calculated mileage?

 

[AngusMacG]

But getting back to the OP - does this built in difference affect the calculated mileage?

Hopefully it keeps the mileage low to protect resale...

 

[Krabby]

Hopefully it keeps the mileage low to protect resale...

I think it would do the opposite TBH.

 

[terdrocket]

With the 35s, my speedometer now reads about 3 to 4% less than actual/gps speed.

 

[TanisIndependentTraders]

But getting back to the OP - does this built in difference affect the calculated mileage?

that is what got me wondering as far as it impacts how the vehicle reports MPG. my calculated mileage is lower that what the grenny says. if the odometer is off the same % as the speedo that might be part of the reason for the optimistic calculation by the vehicle.

 

[anand]

that is what got me wondering as far as it impacts how the vehicle reports MPG. my calculated mileage is lower that what the grenny says. if the odometer is off the same % as the speedo that might be part of the reason for the optimistic calculation by the vehicle.

Same reason most vehicles in general show a higher speed than actual and also report higher MPG than actual

 

[shiv.nandak]

1. So just to clarify from this thread, bigger tires correct the speedo and mpg calculations (up to a certain size)?
2. What about the ODO? Is it currently accurate or will it be corrected by bigger tires?

 

[DaveB]

1. So just to clarify from this thread, bigger tires correct the speedo and mpg calculations (up to a certain size)?
2. What about the ODO? Is it currently accurate or will it be corrected by bigger tires?

Australian laws require the odometer to be accurate within 4% and the speedo to read zero per cent under to 10 per cent above the actual speed, so manufacturers typically set it at about five per cent over