Actually my cars advancer was a bit faulty thus it made it quite difficult to adjust and fine tune it. I used to tune it and after few kms the tuning used to ruin i.e green light not turning off and red light not turning on i.e car not advancing and stalling badly. I just gave a try and changed the advance setting from static to dynamic. Now with dynamic advance you do not need to adjust the setting, it just advances at all engine speeds according to the programming already done on the chip. Now I dont feel any problem even with AC on in parking the rpms do not drop and initial starting in first gear is smoother. The most amazing thing is conversion car starts in half self and automatically converts to CNG at 800rpm without any accelerator, so you can imagine how quickly this advancer is advancing the timing to let the car perform in a good way.
The thing that led me to this was another fact as well. In static advance you just change the amount of advance on CNG and it is same for all rpms whether its 1500rpm or 5000rpm. Now how is that possible that an engine with all the sensors and ecu needs same amount of timing on all rpms range. Now one can argue that the engine will itself change its rpms so the final rpms will be changed, but what you are doing is 6+6=12 and 12+6=18. Now it might be that when the timing is advanced to 12 the engine will work properly at 16 or 19 degrees, now with timings not upto mark your car will not perform equally at all rpms and load ranges. There are 2 types of static advances available one is from idle other is away from idle. The most common and almost 98% in pakistan is advancing away from idle. It is the mode where the cars timing does not increase when the car is in idle but it advances when it is in higher rpms than idle. The other one is where same amount of timing advance is applicable in all rpm ranges whether it is idle or higher.
Both have disadvantages. The common cons being that an engine does not need same timing advance at all engine rpms so the problems like rpms drops, problem with AC on in idle, and conversion to CNG with use of accelerator which is harmful if done on a cold engine.
An advancer is alreading pre programmed so that it determines itself the amount of advance needed at certain rpms based on the readings it receives from TPS, MAF or MAP and other sensors if I am missing any. The resultant is that suppose an engine idling at 800rpms has a timing of 8 degrees, now with reading from all the sensors the advancer calculates that to function properly on CNG the car will need a timing advance of 2 degrees so it advances the timing to 10 degrees, unlike static advance which will advance the timings by 6 or any degrees, thus resulting in the the car not converting to CNG properly+rpms drop+uneven performance with AC on at idle.
Suppose the same car is running on highway at 3500 rpms, now all the sensor tell the advancer to advance the timing by lets say 6 degrees so it advances the timing accordingly and engine performs optimally. Now a car with static advance set at 6 degrees will perform best when it reaches the 3500 rpm point ,while the car with dynamic advance will perform optimally at all rpm ranges and also reaching to 3500rpms. Now this will result in car not giving driving pleasure on highway as they say "BAITH JATI HAI" and also problems in climbing mountain tops.
Now I think I have given plenty of example so I should narrate my practical example. My car converts to CNG without any accelerator, AC performance is excellent even in idle, no rpms drop, climbs mountains easily does not struggle, before my top speed with reduced amount of CNG was 125 km/hrs but now it is close to 140 km/hrs with same reduced supply of CNG, increased pick and last the increased mileage. My cars mileage has increased by 10% although I attribute the 5% increase to reduced supply of CNG
Now the question arises that I have used the term reduced supply plenty of times, what does it mean. Whenever we go to CNG workshop to get CNG tuneup what he does is rev the car to 5000 rpms or more and than set the optimum flow of gas. Although the performance is good but you are consuming more gas. Let me tell you that how many times in city your car crosses 3000rpm rest alone 4000&5000rpm so why tune your car for performances upto that level if you are not reaching that level. So what I did was that I reved the car to 2800-3000 rpms and tuned my car for CNG on that spot & believe me put a mark before setting and after setting I noticed that I had closed the supply screw by more that 1 1/2 twist or close to 2 turns, now thats a mean reduction.
In the end of all this debate there is one contingency that is that the dynamic advance mode might not work with every car, but I will advise you to atleast try it on your car, you just have to move the lever and if it does not work you can always revert back to original settings.
Regards