CNG stands for Compressed Natural Gas, which as its name suggests is "produced by compressing natural gas to less than 1% of its volume at standard atmospheric pressure." It can be used as a fuel source for internal combustion engines, where a cylindrical tank feeds the gas through fuel lines via a pressure regulator before reaching the combustion chamber to be mixed with air and ignited by spark plug.

Like LPG – or Liquefied Natural Gas – it's often viewed as a cleaner and cheaper alternative to petrol, diesel or gasoline for transportation and can be found installed in buses, trucks and even cars and trikes. Though there have been CNG conversion kits available around the globe for a while, the upcoming CNG motorcycle from India's Bajaj Auto is claimed to be the world's first production model.

Prototyping has been underway since at least last year, when the company's MD, Rajiv Bajaj, told CNBC-TV18 in a November 2023 interview that it had recorded "a 75% reduction in carbon monoxide" with the CNG prototype compared to a petrol-fueled moto, while also noting a significant drop in CO2 emissions and "almost zero" non-methane hydrocarbons.

He also reckoned riders could look forward to "a 50 to 65% reduction in the operating cost in terms of the fuel bill." So there appear to be solid environmental and penny-pinching benefits to such a moto being released, and Bajaj Auto's home turf is probably as good a production testbed as any to start the ball rolling – where the motorcycle market in general is projected to be worth some US$31 billion this year.

At the time of the CNBC-TV18 interview, the company was working toward a 2025 launch window, but it looks like that timeline has now been revised, with the Times of India now reporting a June 18 announcement.

Road-tested prototypes look to have started life as regular models before being modified for the new fuel source. ZogWheels posted a couple of pics of a camouflaged bike with a comically large fuel tank in March, that was reportedly benchmarking runs alongside a Bajaj Platina 110 model – suggesting that the CNG bike could roll as a 110cc-equivalent.