This threewheeled gaspowered quarter ton lightweight mail delivery van is known as a mailster It was produced by Westcoaster Company and could hold five hundred pounds of mail By the early s mailsters comprised onethird of the postal fleet Unfortunately they did not work out as well as postal officials had hoped A few inches of snow could immobilize them The threewheel design left mailsters susceptible to tipping They were prone to breakdowns with everything from brake and clutch failure to broken front axles and gear shift levers The mailsters were phasedout and replaced by more reliable vehicles including jeeps