Formula 1 car must have four uncovered wheels and all must be made of the same metal material that has to be one of the two magnesium alloy prescribed by FIA. The front wheels must be wide between 370 and 385 mm, and the back between 455 and 470 mm.
The width of the tread of the front tire is 305 mm, 405 mm and the rear, an increase of 25% compared to 2016 (245/325 mm). Along with tires, wheels shall not be greater than 670 mm in diameter (680 mm with rain tires).
Measurements are taken with the tyres inflated to 1.4 bar. Tyres may only be inflated with air or nitrogen. Teams are not allowed to modify the tyres in any way or treat them with solvents or softeners.
Tyre blankets are permitted, but they may only act upon the outer tyre surface.
Wheels must be attached with a single fastener and tyre guns used to remove tyres may only be powered by compressed air or nitrogen.
Any kind of sensor systems may only act passively.
FIA F1 2017. Technical Regulations can be downloaded here.