In the first COE bidding exercise for September, COE premiums for Cat B rose, while Cat A and E fell.

Premiums for Cat A, for cars up to 1,600cc in engine capacity and with an output of no more than 130bhp, went down by $1,828 (3.4 percent) to end the bidding tender at $51,506.

Premiums for Cat B, larger cars with more than 130bhp or engine displacements larger than 1,600cc, went up by $502 (0.9 percent) and ended at $57,002.

In Cat E, the open category, prices also fell by $67 (0.1 percent), with premiums closing at $56,889.

The increase in Cat B premiums is likely caused by the launch of mid-sized cars like the new turbocharged 1.5-litre Honda Civic and the new Mercedes-Benz E-Class, which might have caused a surge in demand for Cat B COEs.