1. What does Volvo mean by 16 inch or 17 inch etc... brakes? What do I measure? Ok this is kinda goofy but Volvo is talking about the minimum size wheel required to clear the brake rotors i.e. system. There is nothing you can measure that will get you that information. Example: if you have 18 inch wheels is does not mean you have an 18 inch brake system. You might have a 15 inch brake system even though you have larger wheels. Remember, it is the minimum wheel so that would mean 15 inch or larger. The best thing to do is call us with the VIN# or when placing an order leave the VIN# in note section during checkout.
2. Can you turn (lathe) Volvo brake rotors? Why not? No you can not resurface, turn or lathe Volvo brake rotors because they are made to such tight specifications that Volvo does not manufacture them with extra meat (metal). European companies do not make rotors that can be resurfaced. They are generally thinner to save weight and increase performance. Remember when Toyota had all the issues with the brakes not being strong enough to stop the car when the gas pedal stuck? Volvo didn't have that problem because Volvo brakes can stop the car even if the throttle stuck (that is my understanding, not verified). BTW you do not have to replace the brake rotors every time you replace pads and in most cases they should be replaced every other time you replace the pads. The 3 common reasons for brake rotor replacement are; 1. too thin, worn down. 2. warped due to getting hot and cooling quickly do to water or snow. 3. The have grooves in them due to worn pads and metal to metal contact. Also BTW your Volvo brake rotors can be thick enough to pass but if it has a groove it should be replaced.
4. Should I purchase genuine Volvo brake pads/rotors or is any brand fine? OK I realize that even though I will be perfectly honest answering this question I know some people will still doubt and/or disagree but that is OK. If you want your Volvo to perform just like new and just like the Volvo people originally intended then yes you should use factory brake parts. The benefits are a factory fit, factory quality and original performance. If you choose an aftermarket brand you may experience more brake noise, brake dust and it may take longer to stop. Having said all of that; if I was on a tight budget I would probably do factory pads and aftermarket rotors. Some Volvo drivers prefer ceramic pads due to less dust and longer wear but with just about everything in life you compromise one benefit to gain another. Ceramic pads can wear down brake rotors much faster than factory pads. Let me give you two examples that show you how changing parts almost always requires a compromise.
Polyurethane bushings were all everyone wanted when they first came out because they lasted longer. The compromise everyone learned is that a harder bushing meant a rougher ride. With tires the softer the tire the better the ride and performance but the faster it wears.