All the automobile advice I give – on this blog and off it – is approached keeping two priorities in mind: Driving safely, and preventing the needless expenditure of money. Functioning brake rotors are important for safety, however, replacing them costs a lot of money. Therefore, it is important to to know when replacement is necessary, and when replacement is simply a waste of money. This is what I will discuss in this article.

Recently, my friend told me that he got his car’s brake rotors replaced at the car’s third service, after it had covered a distance of 30,000 km. This came to me as a huge shock, because I was always under the impression only high end car garages replaced brake rotors along with brake pads. This car costed under 8 lakhs – certainly not high end. In my view, replacing brake rotors so early is a criminal waste of money. Donating that money to a charity would have been a better use of it. I am not saying that one should compromise on brakes, because brakes are crucial to safety. However, in this case, those rotors would have comfortably lasted at least 60,000km, because there was no wear and tear. In my own experience, I have never had the rotors on my cars replaced before 100,000km. Only if the discs are made of cheap material do you need to get them replaced every 30,000km. Other reasons are:

1. Driving with worn out brake pads. This leads to excessive wearing out of the rotors because of metal to metal contact.
2. Violating highway speed limits (going above 150 km/h) and braking excessively.
3. Driving in coastal areas (more rust).
4. Off-road vehicles are more exposed to damage from dust particles.

One key piece of advice when deciding whether or not to replace rotors is to not rely only on distance covered. Instead, ask for the manufacturer specified minimum thickness limit and measure the rotors yourself (with a micrometer, not vernier calipers). Some drivers are so careful that even their brake pads last for 80,000km. So don’t only go by distance. If the thickness as measured by you is less than the limit specified by the manufacturer, go ahead and get the discs replaced.

Remember, the front rotor always wears out more than the rear. Roughly, you would need to replace the rear rotors half as often as the front rotors. Above all else, please don’t get them replaced blindly.