Can  CNG be fitted in an automatic car ?  CNG in automatic car.

CNG in automatic car  ? This  is a frequent querry and people are skeptical whether  CNG can be fitted in an automatic or autoshift car . The transmission type of the car  has no effect on success or failure of the CNG system in a car.  Yes, CNG  in  automatic car  is successful.

Automatic cars car run  on CNG  as good as that on Petrol.  It’s important to use high quality  equipment in the kit, like constant  pressure reducers, latest generation  ECU with updated softwares as well as fast response time CNG injectors. In automatic cars, the gear shift is done on basis of engine achieving a preset RPM and engine load. Thus it is paramount to ensure that on CNG the same pattern is followed to ensure a smooth gear shift from the gearbox. This can be controlled by two main parameters vis FAST CNG INJECTORS and matching fuel trims on CNG with that on Petrol via the CNG software which has this capability. Injectors like EG2000 and Matrix have a response time of 1.1 ms compared to the conventional type injectors which have a response time of 2.5 ms help in quick gear shifts as per the MAP specified by the car manufacturer on Petrol.

Thus, it’s important to have installation done correctly by an expert. Simple things like placement of manifold nozzles, CNG hose size length , CNG injector nozzle size etc can make a big difference in performance of the CNG in Automatic car.

One should ensure that while calibrating the car, the installer takes interest to match the petrol fuel trims and CNG fuel trims using an OBD2 scanner or has his CNG software showing these fuel trims which enables him to tune the car properly. This would also require some experience from the tuner as he needs to drive and see whether the entire MAP is covered in this way. This ensures that there are no MIL lamps on the car while running due to Rich or lean fuel trims.  Please also remember that both leaner fuel as well as richer fuel on CNG than the one desired/set by the car manufacturer on Petrol is harmful and can damage your engine, catalyst and other systems –besides this condition would always make your car sluggish on CNG . Thus the installer should ensure that he is always as close as possible to stoichiometric ratio on CNG. Once this is followed, it would automatically ensure that the gear shifts by the CVT are also done at about same RPM and engine loads as that on Petrol. This way  you can fit CNG in an automatic car.

CNG fuel burns slower compared to petrol and thus the power delivery from the engine maybe slower. In some cars – specially older or un-maintained cars, it may be necessary to improve the spark of the car by way of changing to a good quality spark plugs like BRISK Silver which increase the quantum of the spark and also by using a Timing Advancer (TAP) which increases the spark duration to the engine by few seconds while engine is running on CNG to make the Gas Fuel / Air mixture ignite fully in one cycle , thus produce optimum power and greater mileage.

There are two types of Timing avancers available, static and dynamic, which can be used depending upon the requirement. The static advancers always advance the timing of the car while running on CNG by certain degree across all engine RPM or load, whereas in Dynamic or Variable advance, you can set different degrees advance at different load conditions (eg at out of idle, high RPM’s, cut off etc ) to ensure a balanced and linear performance necessary for the engine on which the automatic gear shifts are also based.

EG Dyamic is one such Dynamic Timing Advance processors which is programmable and can be set up with different timing advance degrees at different engine loads based upon the car’s RPM, Throttle position and Manifold Absolute Pressure (read load %)  to get smooth gear shifts  from Automatic transmission  car  on CNG. While in static advancers one can only set one type of degree advance via a combination of micro switch , in EG Dynamic, one can set different advance degrees for different speeds and see the load and RPM conditions of the car  graphically via the EG software  for maximum efficiency, smooth gear shift  and performance to ensure CNG in Automatic car.

We hope the above mentioned points would help you achieve the best performance and efficiency from your Automatic / Autoshift transmission  car  . Visitors may please feel free to contact us for any technical clarification regarding your already converted vehicle to CNG at

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