[breezydrive]

Just for the sake of my knowledge, wanted to know which engine is better suited for fitting the cng kit

[nitrous]

Whether its a carb or MPFI, the CNG kit (open loop) is gonna work like a carb anyways.

[mail4ajo]

I would always prefer a CARB engine. But since all cars are MPFI now, we dont have a choice.

Even in a MPFI car, I have understood that open loop or CARB type LPG installation is best.

[wolfinstein]

Less complications involved since Carb engines essentially don't have Sensors and ECU's, but some which do still do not Map the variations of Lamda O2 readings, Air Intake etc etc. But Def not recommended, neither Safe since the fuel supply is not electronically controlled, plus the Lack of O2 readings cannot say the mixture is Lean or Rich, Depends on Excessive Manual Tuning.

However I have heard that Older Padmini and NE 118( Taxi's) running in Mumbai and Pune on Carb systems have LPG or CNG kits.

MPFI engines better suited since the Sensor assist in Tuning the CNG-Air Ratio for a Lean MIX, Also in an MPFI Car the Emmulator shuts the MPFI System and Emmulates the Signal to the ECU-So Safety of only Gas or Only Petrol Modes.

Closed loops are best,since they involve auto mapping the Lamda Readings and adjusting the CNG ratio based with a Stepper and Lamda ECU.

Open Loop are Semi Automatic systems,which need periodic adjustments to control CNG Ratio.

[phamilyman]

I only know from experience:
m800 open loop cng (97 carb)
indica xeta closed loop cng. (06 dec mpfi)

m800 was a bullock cart on cng. xeta is just as peppy as normal - very little feeling that you're driving a "gas" vehicle!

mpfi+lambda sensor is the way to go.

[scorpio118]

Exactly phamilyman - I'm installed CNG in my newly purchased Wagon R (April 07) during September. The Kit is closed loop, and the car is behaving jus as normal as a petrol vehicle. Difficult to guess that it is running on gas....! for MPFI+Closed loop kit.