formatting link
The standard 165/75 15s are about 24 inches in diameter, so use that to compare with any new tyre.
Going to a tyre with a smaller diameter will cause your speedometer to read too fast -- which is better than reading too low, but still not good.
For example, if the standard tyre is 24 inches in diameter, a tyre which is 22 inches in diameter (lowers the car one inch remember) would read about 15% fast (60mph would read as about 69mph.)
You might find that 195s rub on the inside of the fenders on full lock, depending on the offset of the rim on the centre section. And if the offest is too far outward (to stop any rubbing on the inside) the tyre might project beyond the fenders, not legal here in Australia and I imagine that's the case in the US too. It would be wise to talk to a tyre dealer experienced in VWs for rim and tyre combinations which will work on the beetle without causing problems.
______________
this is not a new lesson, been dealing with it for years....
Jim347a note: you might have to remove the charcoal canister to get the right rear tire to fit. It doesn?t work anyway. It is just for looks. Maybe a universal charcoal canister is available that can be relocated.
Note: Once you get the new wider smaller diameter tires mounted, it would be nice to be able to drive past a digital radar speed sign to verify the following.
15% of 5 mph = 5.75 mph
15% of 10 mph = 11.5
15% of 15 mph = 17.25
15% of 20 mph =
15% of 25 mph
15% of 30 mph
15% of 35mph = 40.25 mph
15% of 40 mph =
15% of 45 mph =
15% of 50 mph =
15% of 55 mph =
15% of 60 mph =
15% of 65 mph =
15% of 70 mph =
15% of 75 mph =
15% of 80 mph =
15% of 85 mph =
I think I will just get used to the conversion table and use the upgrade conversion cash for more important upgrades. Thnks to all that replied. I appreciate it!
-------------------- your math is questionable... if the new tire is 15% smaller, why would you want to add to it? I wouldn't....
I had estimated my speedometer to be off by 11% or there abouts...(based one tire size calculators and surrounding traffic.)... My Garmin has pretty much confirmed that... don't trust the portable radar signs that police departments put out, they are not usually well calibrated and are there to draw attention to your speed, not for accuracy of your speed...