Taxi's in Bangkok use LP Gas

It was our last day in Thailand and we needed to go and fetch those tailor made rags (suits) from our Tailor (sweatshop). Our taxi driver was about 60 - 70 years old and drinking red bull like there was no tomorrow. Barry pointed out to the guy that there was no petrol in the car. He said that this car didn't use petrol and it used gas. Well , we pulled into the filling station and he opened up the boot and refilled with LP gas, very interesting...