Car tyre speeds?
Answers:
It is safe, as long as you drive within the limits of the other three, lesser rated tires. It is, however, always a good idea to change tires in pairs (or all 4 if you can afford it), like the front tires at once or the back tires at once. If the car is front wheeled drive, put the best tires on the front for better traction and visa-versa if it is rear wheeled drive.
We spell it tire.
It is probably not a speed rating but rather a mileage rating.
In general having 1 tire different than the rest (whether it's size, tread, wear, or speed rating that is different) can cause premature wear and can potentially cause handling problems. My suggestion would be to buy a second tire to match the new one, and place both new tires on the front axle, as the Astra is front wheel drive. The ideal is to buy 4 completely new tires, but if your old tires still have some life left, you can get away with only two.
It is perfectly safe to contiue to run this setup,However,unless you are on a controlled circuit,I would not advise 210km/h speeds.
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