speedometer re-calibration

[Bykrdon]

I dont even have my smart yet, but spend time looking over the threads. With regard to putting 16" of 17" wheels and tires on the smart, how is the speedometer re-calibrated for the larger diameter tires and wheels?
Thanks
Don in NC

[jwight]

It isn't; if you have a GPS you can check your actual speed that way.

[Turbo42]

The speedo is off to begin with

[Padawan]

Originally Posted by Bykrdon

I dont even have my smart yet, but spend time looking over the threads. With regard to putting 16" of 17" wheels and tires on the smart, how is the speedometer re-calibrated for the larger diameter tires and wheels?
Thanks
Don in NC

The idea is not to have larger overall diameter tires. As the size of the wheel increases, the aspect ratio of the tire is reduced in order to maintain the same overall diameter. If you change the overall diameter, you also alter the effective gearing, which isn't something you really want to do.

Tire size calculator

[epbrown]

Originally Posted by babybenz

The speedo is off to begin with

All German cars are, due to laws there. The manufacturer has legal issues if the speedo over-reads, so they all play it safe. They're typically 3-5% off.

[Bykrdon]

Thanks for the replys. I guess I'm from the old school, when you changed the color coded plastic transmission gear and GPS meant "go piss in the sand".
Don in NC

[PeteInLongBeach]

Originally Posted by babybenz

The speedo is off to begin with

Mine is only about 2 mph over my GPS displayed speed.