SINGAPORE: Singapore Customs said the number of people who violated the three-quarter-tank rule doubled last year. It said the figure went up to about 4000 compared to that the year before. The rule, which has been in place since 1991, requires all motorists travelling north out of Singapore, to fill their petrol tanks to at least three-quarter full. One driver said: "The (petrol) prices are pretty high right now. If I’m going to Malaysia, I will go with a three-quarter tank, and top up to a full tank before returning to Singapore. "I think that's the norm — a lot of people do that". Another said: "Most of the time, I go in with three-quarter tank or more than three quarters, depending on the situation. I mean, since I'm going to Malaysia, I might as well top up there". In Singapore, petrol costs about two dollars per litre, while in Malaysia, it's about RM1.90 or about 80 Singapore cents. The price difference is why Singapore motorists are heading north to fill up their tanks. Singapore Customs said the number of people violating the three-quarter-tank rule has been on the rise between 2008 and 2010. Offenders face a maximum fine of S$500. Some motorists go even further by tampering with their fuel meter. Last year, 23 car owners were charged with that offence, down from 24 in 2009. In 2008, there were only four such cases. Offenders who tamper with their fuel meter face a S$5000 fine or a year's jail. -CNA/wk