From government's perspective, 350cc is not a necessity. It is a lifestyle statement which is a SIN. "SIN" in a country where per captia income roughly is $2,800 (Rs250,000) per annum and BPL of 25%. Motorcycle are for commuting, cheapest and fastest way from Point A to B So if still you have that adventure and touring spirit who want to do Chapter Runs and MA spending lacs of rupees, it is a clear assumption that you are financially well off and way up ahead of the poverty curve. Hence 40% Tax