2008 Gen 2 tyres question

195/55R16 is correct. That's the only dimension I'm allowed to drive with my 2008 Gen 2 in Germany as it's written in the user manual and (more important) in the vehicle registration documents. As this are European documents, I think, yours should show your official correct wheels, too.

The meaning of the numbers:
16 -> 16 inch (=406,4 mm) is the diameter of the rim.
195 -> 195 mm is the width of the tyre.
55 -> 55% of the width is the radial height of the tyre.

So the diameter D of the whole wheel is
406 mm + 2 × (195 mm × 55%)
= 621 mm
The circumference is π × D = 1950 mm = 1,95 m.

With 195/65R16 the circumference is 2,07 m. (That's +6,15%.)

That means now speedometer is showing 100 km/h while you're driving 94 km/h for real (GPS?). That's similar to mine. (While I'm driving 100 km/h (GPS) the speedometer is showing 106 km/h.)

If you'll change back to the smaller ones, which should be the right ones, you'll get even slower (about 88 km/h) while the speedometer still shows 100 km/h. That's a bit too much difference, I think.

But better too less than too much at the speedometer
While you're only on some German autobahn allowed to drive with unlimited speed, the reduced maximum speed of your Prius with the smaller wheels shouldn't be any problem for you in Greece, I think. But the smaller wheels results in higher torque, which results in higher acceleration (if they don't slip).

It's your decision. Consider the speed thing but also your legal situation, which I don't know. (In Germany I'm only allowed to use the wheels, which Toyota let write into the registration documents.)

SM-G950F ?

 

The speedometer is showing 106 km/h mostly (sometimes 107), while driving real 100 km/h (measured with the GPS of my cellphone)
(At least in Germany it's a law that speedometers are allowed to differ up to 10% but never must not show too less.)

SM-G950F ?

 

To prove my dimensions, have a look at the pic. I'm using exactly this size (but with a lower speed index than V, as the car can't drive up to 240 km/h and tires with S, T or even H are usually cheaper).
And I remember these speeds, when driving (all in km/h)
Speedometer – GPS
54 – 50
86 – 80
106 – 100
138 – 130
170 – 160
The difference isn't an exactly linear factor, but that's my experience with my 2008 Gen2 Prius, bought from my dad, which was the first owner.
Maybe your previous owner (the one of your car, of course! ) switched to some bigger tires and to prevent, that the speedometer shows less than the real speed, he eventually let the speedometer get newly calibrated?

SM-G950F ?

 

Thanks, you too!

SM-G950F ?