All right, finally after the long delay, I'm here to post the CNG review. Please bear the picture quality since the earlier ones were with my K750i and these are with my K 700i.
CNG Kit consists of CNG Cylinder / Reducer Electronic Controlled / Solenoid / MPFI Emulator / Analog Gauge and Digital Converter LED Switch / ECU / Copper Fuel Lines / Rubber Washers, Housings, Pipes etc Heat and Flame Proof.
Initial Installation of the system took 4 Hours Aprox, almost a full working day...Not that the system takes much time, Its that the Cylinder Stand needs to be fabricated to fit properly into the rear, The carpeting is then removed and half a inch hole is drilled into the LHS rear side to allow fuel lines. These are neatly housed and sealed with a rubber pipe which has a Manual switch just before the cylinder so as to allow closing of cylinder Valve incase of leak or No use.
The assembly inside the engine compartment is a very tedious task; it involves creating space to install the reducer and other related equipment. The power supply to the system is sourced by adding and external connection into the battery directly controlled with a fuse system.
The reducer connections come from the CNG Tank in the rear and with a thick Rubber insulated Copper pipe connect into the throttle body with a specially installed disk and nozzle.
The throttle body is only modified and nothing else in the engine component is tampered with. The emulators connect into the Cars ECU to directly send signals when into CNG mode.
The CNG ECU is ready for installation sometime this week, so I will post details about it later. So right now this system is the Basic CNG System without an ECU or Lambda Sensor. Results can vary between XETA's.
Before CNG installation My XETA had clocked 1500 KM (1.5 Months Old), Thanks to the delay of non-availability of 12 Kg cylinder and the still awaited ECU.I'm glad that this was delayed till the car crossed 1000 KM so that the engine could have a nice Run in period.
During this time I covered a distance of 36.4 KM daily at speeds of 60-80 KMPH-Around 1800-1900 RPM as shown by the Tacho.AC being on lets 30% of the time since mornings are cooler during the monsoon season. The XETA was clocking an average of 11.8 KMPL.Well this is almost Max of what a XETA can do since 14 KMPL is what is advertised as under Test conditions. Considering the heavy body, Powerful AC and 1405 cc engine it is fair enough although pretty expensive to the ex-chequer since my daily expense was around Rs.100.
The CNG System in total costed me around Rs.48, 000/-(Including CNG kit, ECU, RTO Charges, Insurance IDV Value), The current rate of CNG is Rs.19.20 Per KG and as of now I'm clocking Between 16-15 KM per KG same style of driving and speeds and same distance. The immediate cost saving is that my daily expense has now come to Rs 40 (Approx) from the original Rs.100.
CNG Filler stations are available almost everywhere in Delhi, many Oil PSU such as Indian Oil, HP have also started to Sell CNG from the main pipe ring line around Delhi. I use the station next to my house, best times are around 10 PM or early morning lower rush of the Commercial vehicles.
The filling process takes around 5- 6 Min on an average, considering the Pressure available. The Tank capacity is 12 KG, but around 9.06 KG is what I can manage to fill in. The logic here is that the science rule of hot gas expansion comes into play, since gas expands in volume when subjected to hot conditions the cylinder Max's out at 9.06. I'm advised that this will go almost up to the full capacity in winters. So 9.06 KG of gas burns 150 KM for me @ Rs 173.
Petrol Consumption is limited to my idling and before shutting off the ignition, so the petrol is marginally consumed for around 15 Min in a week.
Lets come to the Operation and Driving around with CNG -
So every morning I start her up and let her Idle in Petrol Mode for a Min, so that the engine warms up. Gradually as I shift into the First Gear and steady her out of the parking- CNG switch is RPM Sensitive and Clicks On at 2000 + RPM and stays on thereafter! So once on the road and gradual speed increase to 20 KMPH with Second gear triggers the CNG with a Soft Klick.and engine takes a small pause and Rev's up into CNG! The speed of 30-50 are easy enough with the 3 rd on CNG and 60-80 Shoots faster with the 4 and later the Fifth once I reach steady and clear roads.
The initial boost from 2 into 3 is slower than petrol, however after that the XETA shoots like a rocket, reaching quick speeds of 60.
The CNG system however becomes slower when shifting from High speed into Low speeds and moving with a higher gear- Lets say I'm on 70 KMPH and suddenly I slow down into 30 KMPH, I need to shift from 4 into 3 and Into 2 to get power else sudden pickup is not that fast as in Petrol- This issue is however dealt with the ECU unit or Advanced Timing Sensor which increases the spark rate with any such change.
With AC, CNG is not that fast- You need to shift into lower gear much more frequently when sudden pickup is required after slowing down, However the power remains good when above 50 KMPH. The AC also cools the same as with petrol so no difference in power.
During Flyovers, I shift into 3 rd gear in speed range of 40-50 KMPH just under 2000 RPM and the car effortlessly cruises along, If you keep maintaining the CNG Speed Ratios You cannot complain of underpowered, but obviously its not zippy as petrol so you can't expect the same.
The Engine noise is more or less the same when running in CNG however the reducer does make a initial whirring noise, however the sound is not loud or irritating its generally of the Gas entering into the reducer unit- Point here is the sounds come generally during the first start of the day right in the morning.
The exhaust system gives out almost no smoke and if you hold your palm towards the exhaust it becomes wet with the Water Vapor produced as by product of the CNG System…Does not mean there is no smoke, there must be but its not visible even in the night.
Most of the driving style of speed and gear ratios change with CNG system, and it takes a little while to get used to it.
I really cannot say much more, but I suggest you take a ride in a CNG car and see how it is or could be adaptable to your driving style.
In all I'm happy that the Car is on CNG and giving me an equivalent performance if not less as compared to petrol.
If there is anything specific anyone is looking for does let me know, Next time we have a Team-BHP NCR meet I will bring along the XETA so you all can test it and see.