The bottom line is that, if a Bangkok taxi-driver can rip off a customer (particularly, a non Thai-speaking foreigner) then he will do so. Examples are legion; none need be cited. My credentials for giving this opinion are 35 years of annual visits to Bangkok, of several months’ duration each year. Taxi-drivers are the only service-operators in the metropolis that I never tip without good reason.
Rodney Griffith
Bangkok