My car is less than six months old. When I drove to Malaysia two weeks ago, I felt a vibration whenever I braked firmly from any speed above 130kmh. Is this normal? If not, what should I tell the service adviser when I send the car for maintenance?

To answer your first question, no, it is not normal.

Vibration during hard braking is most commonly caused by uneven brake disc surface, most likely from the front discs, as the rear brake effect is only about 30 per cent of total braking force.

Often, this can happen in a new car if it has not been run-in properly. When running in, excessively hard braking should be avoided at least in the first 1,000km or so.

If you have been diligent with the running-in of your new car and still experience the vibration, you should send it to the dealer as soon as possible.

Since high-speed brake tests are not possible in Singapore, ask the service department to measure the "flatness" of the disc using a dial gauge.

There is always the possibility that new discs have a manufacturing defect that could cause the vibration.

Shreejit Changaroth