Vehicle buyers will have fewer Certificates of Entitlement (COEs) to bid for in the August to October quota period. The rare contraction, coming on the back of a series of expansions, occurred as more car owners sought to extend the lifespan of their cars. This led to fewer deregistrations - the main driver of fresh COE quotas.

For the next three-month period, there will be an average of 8,613 COEs per month, down by 10.6 percent from 9,634 in the current May-July period. COEs for cars up to 1,600cc and 130bhp will see a 9.4 percent dip in supply to 4,016 a month. COEs for cars above 1,600cc or 130bhp will experience an 8.6 percent shrinkage to 2,672 COEs a month. The Open category, which can be used for any vehicle type but ends up mainly for bigger cars, will have 857 COEs a month, or 16.6 percent fewer.

Currently, about 20 percent of car owners are choosing to extend the lifespan of their rides by revalidating their COEs. Hence, fewer certificates go back into the system.

Commercial vehicle owners will have 23.2 percent fewer COEs per month, with the supply further suppressed by better response to the Early Turnover Scheme. In this scheme, owners of old, pollutive diesel vehicles are encouraged to scrap them for new vehicles at a concession. These owners effectively have their existing COEs revalidated or extended, so their COEs are not recycled. Meanwhile, the supply of motorcycle COEs will contract by 9.6 percent to 718 pieces a month.