Re: GT wings.. legal or not?
Nicely said Speed Merchant, it's true, but the margins are slim on newer cars, but they all read 'the term is - optimistically', ranging from 3-5% normally. Which then allows for about 8mm of treadwear. That is why it's paramount to keep your rolling stock very close to OEM, especially on older vehicles. Even a 2% underrun (say when you change from 215 44/18 to 225 40/18), could mean a further 4% with tyre wear, putting me over 100kph when indicated.
Best way is to verify via GPS, with the more satellites the better (6 or more)!