Question : MY car's OEM tyre size is 195/55 16
Run flats are expensive to replace and are uncomfortable.
I am thinking of using normal tyres.
This size is hard to find for normal tyres and I am aware of the three per cent guideline when we up or down size the OEM tyres as replacement.
The following sizes are suitable for my car - 205/55 16 and 205/50 16.
I have been told that it is better to replace my tyres with the former size because it is less damaging to the car transmission as it is 1.7575 per cent slower than the OEM tyres.
The latter, which is faster by 1.539 per cent, will be damaging to the transmission.
May I know your view on this?
Is it true that when car manufacturers set/calibrate their cars' speedometer, they set it 3km faster than the actual speed to allow room for "error"?
I see no problem with either size of tyre except that I would prefer the 55 per cent aspect ratio simply because of the potholes on our roads and the lower the aspect ratio, the better is the chance for your wheel to be damaged.
The 3% built into the speedo readings is a + or - 3% and not + 3%.
This is the accuracy tolerance and will vary from manufacturer to manufacturer.
I would think that today this is much lower but we all use 3% as a rough guide.