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Old 4th September 2006, 17:53   #1
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Default The right Gear shifts?

Hi Guys,

Have heard this a couple of times and thought that i might check it with everyone and have some technically correct insight too. Apparently to squeeze the most out of a litre it is best to upshift to the highest possible gear and go easy on the accelerator, even when the speedo drops below the 40kmph mark. Is this true or is it better to stick to the frequent gear change style to maintain the tacho at 2.5k rpm?
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Old 4th September 2006, 18:18   #2
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there is no hard and fast rule to this which one can follow to every car. one just has to drive as per torque available in car. if it seems to give jerks after going under 40kph in top gear, better downshift to a lower gear and then raise the pace!
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Old 4th September 2006, 21:03   #3
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for a mileage drive you would need to short shift thru all your gears, but be sure not to loose torque...but mostly u'll get that instict when to change gear once you have driven your vehicle for quite some time, you wont need to look at rpms and change gear.
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Old 4th September 2006, 21:22   #4
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As Far as my Knowledge goes..... maintainig a near-steady rpm preferably 2.5-3k, should do a good job but even the speed matters. This is because the momentum changes with speed and even the nature of losses (friction, air resistance etc.)! that is why the best speed is considered about 80kmph in the 5th gear for most cars! at this stage most of the fuel is spent just in sustaining the motion achieved; that too with the engine in its most efficient rpm band.
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Old 4th September 2006, 22:34   #5
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Well maruti recommends...
1st to 2nd - 10 km/h
2nd to 3rd - 20 km/h
3rd to 4th - 30 km/h
4th to 5th - 40km/h

Now this is what honda recommends... (extract from owner's manual)


Point to note is that Maruti's gearing is normally taller than the honda City....

Anyways... I'd say honda is more close to healthy gear shifting, Maruti is still stuck in 1984...

Honda's logic to making the engine run in a gear where it feels comfortable is the *key*

Last edited by SLK : 4th September 2006 at 22:37.
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Old 4th September 2006, 23:22   #6
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It varies from car to car..... It is logical that when an engine is taking minimum efforts to move the car the avarage is maximum and again due to excessive speeding the engine is over strained, it results in more petrol consumption than usual.. Now big cars like skoda, it gives an excellent average when the car is driven at somewhere between 80KMPH to 100KMPH. Thanx to it's information display... You can immediately conclude how efficiently your car is running... But same is not the case with maruti alto/ Hyundai santro or any of the smaller cars..... What I mean to say is economy zone varies from Smaller engines to bigger engines...

Cheers
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Old 5th September 2006, 11:24   #7
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SLK,
thast a nice detailed pic you posted.
but imho, if somebody follows this pattern even in his honda, he'll be getting traffic challans everyday! and no great fuel economy too!
i mean as per this manual, to maintain 50-55 kmph in cities, one has to be in third gear all the time doing 40-64kmph, and we all know one just cannot get best economy in a third gear!
please post your opinion.
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Old 5th September 2006, 11:45   #8
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Yes... I think the manual's recommendation is valid in a situation with full load and AC.
But again if you are not to accelerate then you are better off at 50+@5th gear. If accelerating then its probably better to do it in the 3rd or 4th gears.
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Old 5th September 2006, 11:54   #9
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Quote:
Originally Posted by SLK
Well maruti recommends...
1st to 2nd - 10 km/h
2nd to 3rd - 20 km/h
3rd to 4th - 30 km/h
4th to 5th - 40km/h
Maruti's recommendatios is just eyewash. They should give recommendations for each model. For example 40Km/h in 5th for Esteem is roughly 1000rpm. If you drive so, you'll get really "shaken"
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Old 5th September 2006, 13:56   #10
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Quote:
Originally Posted by WhiteKnight
Maruti's recommendatios is just eyewash. They should give recommendations for each model. For example 40Km/h in 5th for Esteem is roughly 1000rpm. If you drive so, you'll get really "shaken"
absolutely. this is ridiculous. the ideal shifts for the esteem would be
1st to 2nd - 10 km/h
2nd to 3rd - 25 km/h
3rd to 4th - 40 km/h
4th to 5th - 50km/h
but all this is situation dependant

like in the highway, if you are going to follow the above procedure, you might find that your car takes eternity to reach 100KMPH.
if you can drive without engine knocking, then you are doing fine.

now, for my IDEAL shift would be
1st to 2nd - 40 km/h
2nd to 3rd - 90 km/h
3rd to 4th - 130 km/h
4th to 5th - 165km/h
that would set your adrenalin pumping, wouldn't it?
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Old 5th September 2006, 14:11   #11
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Quote:
Originally Posted by ash7678
Hi Guys,

Have heard this a couple of times and thought that i might check it with everyone and have some technically correct insight too. Apparently to squeeze the most out of a litre it is best to upshift to the highest possible gear and go easy on the accelerator, even when the speedo drops below the 40kmph mark. Is this true or is it better to stick to the frequent gear change style to maintain the tacho at 2.5k rpm?
the best fe achieved at 50kmph-60kmph in top gear.....i think 2.5 rpm is a bit too much....change at 1.7 rpm - 2 rpm and note the difference
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Old 5th September 2006, 14:17   #12
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For the Octy , when im in extreme conservation mood - I shift up at 1500 RPm
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Old 6th September 2006, 00:07   #13
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Quote:
Originally Posted by esteem_lover
absolutely. this is ridiculous. the ideal shifts for the esteem would be
1st to 2nd - 10 km/h
2nd to 3rd - 25 km/h
3rd to 4th - 40 km/h
4th to 5th - 50km/h
Quite right (carb Esteem)... it's slightly different for the MPFI Esteem and it's better if you use the Tach to decide when to shift gears instead of the speedo...

Here's my experience with a E-II MPFI Esteem burning IOC Xtrapremium (91 Octane), the engine has to be revved up slightly higher for standard 87 octane petrol:

Economy Driving:

Up shifts:
The idea is to disengage the clutch while taking your foot off the accelerator, smoothly slot up a gear and release the clutch (without accelerating) in such a way that there are no jerks (engine rpm matched with the gearbox rpm) and the engine has enough torque to pull the car in the higher gear (without knocking). Once the car is "rolling" in the higher gear, you can gently accelerate. If you do it right and shift smoothly without forcing the box, your engine rpm will have dropped slightly and it will (almost) match the downshift rpm table (next list).

1st to 2nd: 1500 rpm
2nd to 3rd: 1500 rpm
3rd to 4th: 2000 rpm
4th to 5th: 2250 rpm (half way between the 2000 and 2500 marks)

Down shifts:
The trick is to let the engine coast down in the highest gear possible where a gentle dab on the accelerator would still have enough torque to pull the car in that gear. Once the engine drops below this rpm, shift down.

5th to 4th: 1400 rpm (just below the 1500 rpm mark)
4th to 3rd: 1400 rpm
3rd to 2nd: 1000 rpm
2nd to 1st: 800rpm (the "idle" mark)

Quote:
Originally Posted by esteem_lover
but all this is situation dependant
like in the highway, if you are going to follow the above procedure, you might find that your car takes eternity to reach 100KMPH.
if you can drive without engine knocking, then you are doing fine.

now, for my IDEAL shift would be
1st to 2nd - 40 km/h
2nd to 3rd - 90 km/h
3rd to 4th - 130 km/h
4th to 5th - 165km/h
that would set your adrenalin pumping, wouldn't it?
I hear ya!

To squeeze the most of your MPFI Esteem, shift when the tach hits 6000 rpm.

I dont know what speeds that transalates to, but I do know that she hits 120Kmph in 2nd ... and you dont need to use the 5th gear... top speed (indicated) is just above 175Kmph in 4th... if you shift up to 5th at 175Kmph, the speed will actually drop gradually to around 165 - 170Kmph.



Watch out: Stomping on the accelerator and redlining an MPFI Esteem in 1st gear can be a real b**ch! With the stock LX (155/80) tyres, this is only good for tyre smoke... even those skinny mopeds will leave you behind on the signal if you try this! (and when and if the tyres finally bite, u end up ramming into 'em from behind!)

With my 185/70 Potenza GIIIs, she still does wheel spins if the surface is anything less than ideal, but now the real problem to watch out for is the torque steer... it could easily send you careening into that skinny moped on the left / right of the car!

Oh... before I forget... dont stomp hard on the gas pedal in 1st on a U turn (unless there's no traffic and you really really want to impress the babe in the red top across the road) ... the car will first shoot out across the road and start a gentle but scary spin... and when you take your foot off the gas in panic, you get a violent "lift off oversteer" spin and end up facing the oncoming traffic... Don't ask how I know this!

- T u r b o C -
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Old 6th September 2006, 18:59   #14
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I remember when my mom went up to the sales guy of alto and asked him as to how mileage can be improved. Pat came the reply, make sure you are driving on the 5th gear the moment you cross 45kmph. Well this can be a good thing to improve mileage, but on what roads. I find myself often stuck on 4th even on 60 because overdrive wont take me up there to the point.

I guess to extract the best out of the car, gear shifts should be at a point where the higher gear will be able to take the load of the vehicle smoothly. There should not be a drag between the gear change. Higher gear driving does not necessarily mean better mileage. Gears can be changed down immediately when the car starts to shake up a bit.

The most important thing when driving i feel is that you got to have the correct feel of the pedal to the vehicle response. often with traffic sounds, or closed windows and good engine refinement, engine sound cannot be heard. So one need to go by the feel as to whether when pressing the accelerator whether the speed is increasing or is it remaining the same. That should be the moment when gear shift down is required.
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Old 6th September 2006, 22:57   #15
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Quote:
Originally Posted by ash7678
Hi Guys,

Have heard this a couple of times and thought that i might check it with everyone and have some technically correct insight too. Apparently to squeeze the most out of a litre it is best to upshift to the highest possible gear and go easy on the accelerator, even when the speedo drops below the 40kmph mark. Is this true or is it better to stick to the frequent gear change style to maintain the tacho at 2.5k rpm?
You are right about keeping the car in lower revs for any speed to get good mileage and engine life. Thats incidentally how I drive. I ensure I always upshift into 5th as soon as possible and stay there as long as possible. I never rev the car. I find that I am able to keep the car steady at 80 kmph while being lower than 2000 rpm!
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