1.   Indeed, they are highly engineered products, with each company keeping its particular curing temperature, tread design and cocktail of rubber compounds a closely held trade secret.

2.   Mixed-up tire sizes and tread designs can cause steering, handling and braking problems that get worse in bad weather.

3.   Most tire companies have developed low-friction tread designs that make the engine work less to turn the wheels and thus promote fuel economy.

4.   The two front tires should match each other in tread design and size, as should the two rears.

5.   They feature reduced mass, an asymmetric tread design for better grip, a more compliant sidewall and better wear.