Do You Need to Replace All Four Tires at Once?
Replacing all four tires is ideal, but it is not always required. It depends on your drivetrain and how worn the other tires are.
Front- or rear-wheel drive
Replacing two is generally acceptable. Put the new pair on the rear axle for the best stability in wet conditions, even on front-wheel-drive cars.
All-wheel drive
AWD systems are sensitive to differences in tire circumference. Many manufacturers specify that the tread depth difference between tires be no more than about 2/32" to 4/32". Mixing a new tire with three worn ones can strain the drivetrain. Check your owner's manual, or replace all four.
Same tire on all four
Matching brand and model gives predictable grip and braking. If you replace only two, match the existing tires as closely as you can.
Shaving tires
Some shops can shave new tires down to match the worn ones for AWD vehicles. Ask your installer if this is an option.