Forgive my ignorance I don't know too much about cars. I have an r60/2014 Countryman. When my bf and I lowered it and changed the suspension he put his wheels on it. He has a 335i or 340i (Always forget lol). Anyway, my mom ended up borrowing my car recently and now the front right wheel is slightly curbed and the tire is flat. How do I go about fixing this? Do I need new tires or what can I do? I'm stressing considering they aren't my wheels.

 

What kind of front tire is it? Runflat or non runflat. What does it read on the sidewall of the tire? Does it say RFT- this means runflat
tire sidewall markings-
https://pmctire.com/en/info/tire-spe...-markings.tire

How do you know it is flat? Just by looking? Did you check the actual tire pressure with a gauge? Did you try to pump up the tire with air? If the tire is flat like under 25 psi then refrain from driving on the tire until you can get more air into it using a portable air pump (ask a friend that might have a foot pump and borrow a tire gauge if you need to).

After pumping up the tire with more air at least to 35 psi then look on the tire treads for any nails, screws or punctures. If you see a nail then leave it and it might be fixable depending on the location of the puncture. ALso check the valve for any visible damage or leaking. If you have a water spray bottle just spray water on the tire surface and air leaks will look like active bubbles.

If the tire can hold air long enough to drive to a tire shop then you can ask them to check the tire and fix the flat if they can. Using any tire repair method is OK if done correctly, it's not that big a deal. If it is a runflat that is punctured some shops will not want to fix it so you can call around and ask before you go there.

Is there a spare tire? If so you can use it if the flat tire cannot hold air.

If the puncture is too close to the sidewall or outer tread areas it might not be able to fix the damage or the area is under too much stress to fix then you may need a new tire. Tires are often replaced in pairs or all four if the wear on the remaining tires is far different than the flat tire, check the tire tread depth and see where they are at. New tires have more tread depth and give more grip and ability to shed water under wet conditions, worn old tires have less tread depth and the rubber gets hard and offers less grip.

In the case of All Wheel drive you need all four tires to be of equal tire diameter so if some tires are more worn then tire diameters may be quite off which isn't good for the transmission. Therefore some all wheel drive cars recommend changing all four tires or at least those on the same front or rear axle as long as front and rear tire diameters are no more than 3/32" difference which is not much.

So just be careful not to drive on a flat tire which can be easily damaged by the rim if there is no air pressure.