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

Rohit, Do you mean disengaging or physically removing the AC compressor? How is the compressor connected to the engine? electrically or mechanically? If it is mechanically, then it would indeed make sense to disengage it. If electrically, I already don't use AC  - switched off.

Update on Alternator Delete idea:

On researching on the net, saw that there was a significant downside to alternator delete - If not careful, it can kill battery real quick. (It may be efficient to charge on an AC battery charger,  but the human being taking care of this has to be as methodic as the alternator and charging circuit in the car. Otherwise, one has to get stranded on the highway, asking for a jump start from passers-by). So dropped the idea.

Compressor is run from the engine using a rubber belt-there are electrical connections also.

Binoy, Is there any serious downside to taking it off the belt? I better take this expert advice in-house rather than scour the internet for answer. I mean no serious harm to the compressor, its gas charge or any of AC components if the compressor is taken off the belt?Is it the same belt that snakes through various systems or is it a standalone belt?

I will take a peep in the hood tomorrow morning, but can't say I will recognize anything much. I am a paper tiger!

It could well be a single belt along with the alternator-removing the compressor will bring down the weight-but an easier solution would be not the turn the AC on at all-will the difference be huge-i guess not.

Hood-peeping report:

There is only one single thin belt, about 0.75 in. wide, snaking over 5 different wheels - One crank, one starter, one coolant pump and one dummy pulley. So that leaves out the compressor (geussed that one to be the AC compressor, because it has thick insulated hoses connecting to it).

Looks to be very difficult proposition to isolate AC compressor alone  (It has to largest pulley to keep its RPM wrt crank low).

@Krishna - what I meant was not using the AC - if the AC is switched off then for all practical purposes the compressor is physically disengaged from the pulley that drives it - the pulley is coupled to the engine by a belt though.

Rohit, If a mechanical part keeps spinning with the engine, it loads it, regardless of whether it is otherwise functional or not. If AC is switched off, it will not load the engine, but the spinning mechanical part, its friction, and loading on the engine are still in place. With physical disconnection, this part is saved.

PS: Actually I am not quite certain I spotted the compressor in the morning peep-in-the-hood. I counted crank, one starter, one coolant pump and one dummy pulley and one unidentified big pulley. It could be an alternator or compressor. Or could the dummy-looking pulley be one of the components?? *confused...*

Tank Update:

Filled my tank today. 787 km from refill to refill - 40.58 liters in all - FE figure... 19.4 kmpl . This tank was all normal city driving - regular use for commuting to office, some particularly short legs picking up and dropping kids to school, some crawling in the city market looking for parking space, some trips on expressway (each ~70 km) I did nothing special for this tank except for a lot of engine-off coasting. Now I can do it like a pro!

Payed attention to the discussion on premium fuel - switched from Speed to Plain Unleaded for this tank - Will come to know by next tankful as to whether the FE figure suffers or not.

Although this tank does represent a 1.4 kmpl improvement over earlier one, I think I am hitting a wall as far as FE is concerned. Will need to do something to move beyond the 20kmpl barrier...

Any suggestions guys...? 23 looks far away in the horizon at this rate...

That is a nice update buddy. Good going.

20KMPL is not far away.

Ami,

I am using all there is at disposal, and getting this 19.4.  The next tank can as well 'tank', because I am not putting much extra in the mix to produce any better results. Thats why I need help for further improvement.

And the target is 23, so we better take that into account rather than the milestone 20, which will surely be a morale booster. 20's not the goal. No way.

OT:

Hey,  I noticed 'New Delhi' as your location... Transferred? Switched? Visiting? Deputed? What exactly?