Why CNG and automatic transmission don't gel well. Key reasons
Compressed Natural Gas, abbreviated as CNG, is one of the cleaner and popular gas-based automotive fuel options in the market. Over the last few years, CNG has witnessed rapidly rising demand and sales across the country due to various factors. It is considered a significantly cheaper fuel alternative fuel compared to petrol and diesel, while CNG also offers a substantially lower cost of ownership to vehicle owners. Besides that, it offers significantly higher fuel economy than petrol or diesel. The increasing focus on greener mobility has enhanced the demand for CNG in India over the last few years.
Buoyed by the rising demand, several car manufacturers are launching passenger vehicles with factory-fitted CNG kits. Besides that, many people opt for aftermarket CNG kit installation on their vehicles. The benefits of the CNG kit-equipped vehicles are multiple. While these cars can run on both petrol and CNG, they also offer a significantly lower cost of ownership.
While CNG cars are witnessing a rise in demand and sales across India, the non-availability of automatic or automated manual transmission with these vehicles is a concern for many consumers. AMT or automatic transmission make driving easier and more convenient for drivers, especially in highly congested bumper-to-bumper traffic conditions.
Here are some truly technical reasons why the CNG cars don't come with AMT or automatic transmission, but manual gearbox only.
A CNG powertrain lacks low-end torque and takes its own time to gain pace. This puts pressure on the engine block to deliver power at a particular instant. The AMT or automatic transmission-equipped cars come with detuned clutches as they are unable to withstand heavy torque and are prone to overheating. Hence, in the need of an instant power requirement, automatic transmission in a CNG car will lag in upshifting gears.
The automatic gearboxes are meant to stay coupled with driveshafts all the time until they are manually slotted into neutral. The lack of low-end power and torque may result in the automatic transmission in a CNG-propelled car struggling to crawl the vehicle when in drive. This can result in premature wear of the clutch, damaging the vehicle's critical component.
While driving a CNG car equipped with an automatic transmission, the driver is bound to experience a considerable lag in acceleration as there will be low power output. A powerful engine can overcome this problem if paired with a better transmission setup but will command a higher cost of ownership. This will eventually not fetch the desired sales volume.
CNG cars come with higher upfront costs compared to their petrol-only counterparts. On the other hand, an automatic gearbox-equipped car comes priced considerably higher than its manual transmission-equipped counterpart. Hence, a car with a CNG propulsion system and automatic transmission will command substantially high upfront cost for the consumers.