Do I have to replace the tires on a leased car?

Only if they're worn past what your lease allows. Most leases ask for a minimum amount of tread left at return — commonly around 1/8 of an inch, or 4/32 if the paperwork uses that scale — and if the tires are below it, the leasing company replaces them and bills you. If they're above it, you owe nothing, even if the tires look tired. So this isn't a question of new tires versus old; it's a question of one number, and you can check it yourself months ahead.

Put a quarter upside down into the tread groove. If the tread reaches Washington's head, you have roughly 4/32 of an inch left and you're around the usual line — that's your signal to plan. If you can see the top of his head, you're under it and you'll be charged. Check all four tires and check across each one, because the inside edge often wears faster than the part you can see. A tire shop will measure them for free if you'd rather not guess.

Almost always cheaper yourself, and it's usually not close. When the leasing company replaces a tire, they charge their price for the tire and the labor and add it to your final bill — you don't get to shop it. Buying the same set from a tire shop or a warehouse store means you pick the brand, wait for a sale, and pay the shop's rate. The catch is that this only works if you know early, which is the whole reason to check the tread at month nine rather than at the return appointment.

They have to be the right size and speed rating, and all four should match each other. Beyond that you generally don't need the exact brand the car was sold with, and you don't need the most expensive option — you're handing the car back, so a solid mid-range tire that meets the spec does the job. If your car came with a staggered setup or run-flats, keep to that spec. When in doubt, give the tire shop your car and your lease's requirement and let them match it.

A single tire below the line usually gets replaced on its own, though many shops recommend doing them in pairs on the same axle so the car drives evenly. Damage is different from wear: a puncture, a cut sidewall, or a bubble is charged as damage rather than measured against the tread, and a curbed wheel is charged separately from the tire on it. If one tire is wearing much faster than the rest, get the alignment checked — otherwise you'll buy the replacement twice.