speedo recalibration for new wheel size?

so lets say i use my trusty CNTRL+W to select a new wheel size and new tires. Overall rim size combined with the aspect ratio give me a new different outer diameter of the tires.

Will the speedometer still show me the real speed?

I am assuming that the game doesn't automatically change gearbox and differential ratios (so smaller tires theoretically give better acceleration but lower redline speed, etc) but will the speedometer get recalibrated automatically? Thanks!

 

speedo remains correct

 

The speedo remains correct... to a point. If the wheel diameter of the new vs the old is only an inch or so, the difference is not noticeable. If you put much larger or smaller tires on a vehicle (like drift tires on a D-15, if you've ever tried that) the speedo becomes inaccurate.
The same thing happens in real life since many speedos are calibrated to the wheel axles, so this is a realistic aspect of the simulation.

 

never duplicated myself. BeamNGs speedo isnt calculated from RPMs multiplied by a base factor but does genuinely read the groundspeed of the wheel.