Is It Illegal to Convert a Gasoline Car to Natural Gas?
3 Answers
Whether converting a car to natural gas is illegal depends on whether it has been approved. Before converting from gasoline to natural gas, you need to go through the approval process at the vehicle registration office. After obtaining approval, the conversion can proceed. Once the modification is complete, you must return to the vehicle registration office for safety certification. If the certification is approved, the conversion is considered legal. Otherwise, unauthorized conversion is illegal. Below is an introduction to converting gasoline cars to natural gas: 1. Advantages: Higher economic benefits. Natural gas mixes easily with air in the engine, burns more completely and cleanly, and is less likely to produce carbon deposits. It has good anti-knock properties and does not dilute lubricating oil, significantly reducing wear on engine cylinder components and extending the engine's lifespan and the service life of lubricating oil. It also offers social benefits, as gaseous fuels result in less energy loss during preparation and fewer harmful emissions compared to petroleum fuels, making them more environmentally friendly. 2. Disadvantages: Due to the low energy density of gaseous fuels, natural gas vehicles carry less fuel and have a shorter driving range than gasoline vehicles. Most current natural gas engines are modified from gasoline engines, so converting a gasoline car to natural gas often results in a power reduction of about 10%-20%. Natural gas is a gaseous fuel and is not easy to store or transport. To address this, it needs to be pressurized or liquefied for bottling, and the construction of refueling stations, which require greater investment than gasoline or diesel stations, is necessary. In areas with limited refueling stations, refueling can be difficult.
It depends on local policies. I once converted my old 1.6L Jetta to CNG but got stuck during the annual inspection. The official procedure requires applying for modification registration at the DMV and obtaining a qualification certificate from an authorized conversion shop. The most troublesome part is the gas tank inspection every three years, costing over 400 yuan. If you casually modify it at some roadside shop, your car will be impounded if caught, and insurance won't cover spontaneous combustion. Honestly, post-conversion savings are real—fuel cost drops from 0.3 yuan/km to 0.15 yuan/km—but the huge gas tank takes up too much rear space, and you'll notice significantly weaker acceleration. Nowadays, new policies allow factory-converted gas vehicles to be directly registered with green plates, which is much more hassle-free than aftermarket conversions.
According to the law, unauthorized modification of vehicle structure is illegal. However, some regions have special policies for gasoline-to-natural gas conversions, such as Xinjiang and Gansu provinces where gas supply is abundant. As long as the modification is done through a certified workshop and properly registered, it can be legally driven on the road. Remember to keep the pressure vessel inspection report and the special equipment usage registration certificate, otherwise the annual inspection will definitely fail. The gas cylinder must be installed on a dedicated bracket in the trunk, and a leak alarm device is also required. Once, my friend forgot to close the valve and parked the car in the garage, and the next day the entire garage smelled of natural gas. The property management almost called the police. It is recommended to check the pipeline sealing weekly after the modification, as safety should always come first.
