How to improve mileage of Honda City (current: 18 kmpl; goal: 23 kmpl)?

Hey I understood P&G as you accelerate to a speed, drive on the speed for some time and let the car slow down on own with gears engaged. The engine braking comes into picture here. I never knew that P&G is about switching-off the engine and then gliding on the road. And if thats the case, I am with Pankaj. Its really unsafe. Specially in today's cars where the moment you swtich-off the engine, power steering as well as brakes are jammed, as told by Rohit. And that makes it the most dangerous thing on road.

However I remember driving my dad's old Fiat padmini, infact saw my dad doing it often on this car, but then its brakes and steering were still well in control and these used to be mininal traffic at that time, around 10-15 years back, that too in small town called Bhilai.

In big cities, I guess you dont have roads to try P&G, in first place. And even if you have its seriously is dangerous. However, when Krishna mentioned about it in his return trip from Karnal, what I understood was that he is talking about letting the car slow down be using engine brakings. And I feel he still means the same. Right Krishna?

Well, Anshu AFAIK the old padmini did not have power steering or engine-assisted braking. Steering was fully manual with just the gear ratio to give some mechanical advantage and the braking too was a set of linkages/levers/cables. So in this case you could steer and brake with the engine off!

For the sake of discussion (whatever), P&G is a vast subject.

As far as we are concerned, the following is the bottom-line...

We may strive for better "fuel efficiency" (nothing wrong) while the engine is running & in gear (NO neutral/P&G or the like).

Yes Rohit. You are correct. And I guess most of the cars we had in India at that time had similar techniques till PS was introduced. However in today's car, almost all the PS cars they have such featuers of PS and brakes getting jammed the moment engine is shut-off.

Probably thats why people used to try this more often at that time than today. I still remember one of the taxi(Ambassador) fellow in Bhopal. He used to turn off the engine the moment slope came and again start it when on flat surface. In this way he used to save a lot on fuel and the also no discounts on charges..so win-win situation for him

And today, such features are necessary, more than comfort feature, as I understand that jamming of PS and brakes also accounts towards safety of the car, as without keys/started engine it would be difficult for theives to steal the car. I hope I did not go OT.

Well, well, I turn my back for a few minutes, and here these two guys run away with my thread!! Help! Help! (Oh, shucks! one of them is a mod! I am screwed! )

Rohit, I am going to call you dummy once again. Justified since I thought you were coming to my rescue in the above dialog, but you didn't!

P&G guys NEVER use self-starter for starting vehicle. That would be madness. The self will die first, then the ignition key switch cylinder. Each is several thousand rupees to change. Then why do people P&G?  Well, they find other ways to start and stop the engine - Starting is achieved by bumping the car - engaging the turning wheels of the car with the engine through the transmission briefly to get the crank turned, that sets in motion the rest of the orchestra of signals needed for the engine working.

Bumping is taken to an art form by the practitioners of P&G. I will do it with you sitting in the passenger seat and you will not even realize it is happening. No jerks, no nothing.

Engine killing is done by a kill switch, which disconnects the ignition coil supply for some time. No need to turn the key, which also can cause accidents.

As to objections that it places extra responsibilities on the driver, who is also dead against talking to passengers while driving? Raise their hand. Also who is against listening to music? Raise their hands. Also who is against looking at that cute distraction on the sidewalk? Keep quiet, for obvious reasons!  

Moral of the stroy is, don't blame P&G alone, and don't do it unless you are sure what you are getting into. Don;'t discourage through wild objections either. Thank you!

I agree to this. My dad used to do it often, as i told earlier.

Do all the cars have such facility? I dont think so. Atleast my safari doesnt have such facility. In that case, how do you kill the engine? Thanks

Kill the engine? With an axe, of course!! ;-) Jokes apart, normally the only way is by turning off the ignition - but you can have an extra switch installed which turns off supply to the ignition coil.

Krishna - question for you - ok that the ignition coil is turned off - but how does that affect the fuel injection? I suppose the ECU will still inject fuel - and that wouldn't be so efficient, would it?

Thanks Anshu bhai, for the support!

Rohit: No. ECU 'sees' that the crank is not turning, and stops injecting. If it did just continue injecting, you would have a flooded engine at hand. And yes, you don't need P&G for that. A stationary or rolling car with engine off and ignition key in ACC2 position (IG2, in some terminologies) will still correspond to the same condition.

Crank not turning - ok if the vehicle is not in gear, but what if it is in gear AND you kill the ignition (with the new kill switch, of course)? Now the crank will be turning, the main ignition switch is in battery position, so will the ECU inject fuel or not?

But Rohit if you kill the engine when car is in gear, will it not start it again with a big jerk depending upon the speed, specially when the ignition key is still in ON position as you have killed the engine using new kill switch? And so the fuel will flow definitely as the car is again back to original state of running. I dont think this is P&G as described above by Pankaj and you, is it?