sham

Questions regarding gear selection

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Hi all,

I own a Fiat punto(mjt) and have been using it from the past 1 year.

From day 1 ,I have been convinced that it has so much of torque that I can start the car in 2nd gear (of course without pushing the car's rpm to insane levels.).

If i drop the clutch slowly i can easily pull the car even under full capacity load.

My doubt is , is this called bad driving?

Will it harm the gearbox/engine in anyway and should I start the car in 1st gear only>:/

(Again, I dont shift to 2nd and over-rev the engine to get it moving, I do it by just handling the clutch in a gradual way.)

Thanks

Shampavman

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Please follow simple rules.To get off the car from a halt always the 1st gear is used. When the car is in slow motion even @ 5-10 kmph the second gear can be engaged.

These simple rules kep the gear box and engine fit.

Anything against the rules can have long term consequences.

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I think one should use the first gear to move atleast equal to car's length, though the car in certain conditions pick up in 2nd also, but the 1.existence of 1st itself the proof that it is required & 2. first gear should technically have more starting torque than 2nd.please do correct me if i am wrong?

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You are 100% correct.

But my point was that if the 2nd can also do the job of 1+2 , and do it very well with ease, why should I use the 1st?

Having said that , if i'm on an inclined road heading up-hill then I most definitely choose the 1st gear to build up the revs before i hit 2nd.

But in most other cases.. I dont feel the need...

Please let me know as I'm looking for answers!

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Thanks for the reply...

But can you be a bit more technical in your answer?

Because if the gearbox can handle the torque generated why not use it?

Thats OK sham but rarely one realises that the engine is strained with such an action. Each gear has specific speeds designated for every particular engine which is mentioned in the owner's manual.

Even in torquey engines the strain is evident in higher gears. Say you engage the fourth gear at  20 kmph, the tappet makes a thud thud thud noise, overheating the engine and straining it.When you start from idle in the second gear this tappet noise is not apparent in torquey engines but caution needs to be exercised.Non torquey engines emit the tappet noise if started with the second gear.

And when a lower gear is engaged at a higher speed- especially needed while overtaking, the engine rpm (crankshaft) is higher vis a vis the rpm of the wheels.There is excess engine noise but this is a less damaging to the engine if compared to the higher gear- low speed manoeuvre.

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Unquote: Having said that , if i'm on an inclined road heading up-hill then I most definitely choose the 1st gear to build up the revs before i hit 2nd.

But in most other cases.. I dont feel the need...

Quote: i think you yourself replied to your query. What i said above is applied when the vehicle is in static position on a plain surface.

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Shan. Car driving skill is one of the important thing which will be interested once if you are fully welly knowledged person. you see, drivers can be divided into slow, medium, fast. Seems like it looks easy to understand while reading it, but ofcourse it is not. The Gear Shift is the major character play at every car/bike. For every type of driving, You must bring the gear lever to the first gear if the car comes below to the 10kmph-12kmph speed. The new cars wont say any objections if you accelerate at the 2nd gear with the standing or slow moving speed below to the 12kmph speed. but plz dont use this method. The rpms should be raised at the low gears , only if they car is gonna be raced or attain high speed sooner. Use the 1st gear(till 13kmph speed), 2nd gear (15 to 30), 3rd gear (30 to 40). 4th gear(40 to 55) 5th gear(55- so on). this is the recommended speed and gear shifting for the commercial driving whatever the roadlane is. So dont forget to minimize the gears step by step for  decreasing into the proper speed, also never jump the gears from 1st to 3rd or 5th to 2nd etc. But minimizing the gear from 5th to 3rd will be popularly for sudden racing driving.

-dinesh

(always the racer wins at last)

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When the torque is there, I don't think of any harm in starting the car/bike in 2nd gear.

FYI, I have never seen someone starting his RX100 in first gear except for some showoff. This act of starting from 2nd gear doesn't harm.

 

Reg Gear Jumping, I often jump 3rd gear unless its overtaking. Never felt anything bad. I think, its waste to shift to 3rd, slightly improve power, clutch, petrol wastage, so I revv slightly more on 2nd and go directly to 4th.

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Gear Jumping is no big deal. IMO, you jump a gear or not, you're using almost the same amount of fuel. You high rev 2nd gear to directly go into 4th, so there extra fuel is burnt. Ok you save 3 drops of fuel! No big deal.

I would definitely recommend shifting through all the gears.

Personally, when I and my friends are on Geri in Panjab University, 3rd gear is the most suitable for going easy and slow and side by side enjoying the Univ.

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Thanks for the reply...But can you be a bit more technical in your answer?Because if the gearbox can handle the torque generated why not use it?

Using Gear other than 1st for Initiation the movement of a car, will Inherently puts the Strain on its Clutch System & leads to its Overheating & Faster Wear, despite of Gearbox's ability to bear more Torque.

Piston Pins, Con-Rods & Tappets are affected later on & in an above Quoted Suquence by Strained Gear-Shaft via Crankshaft.

So, is the Utility of 1st & other Consecutive Gears w.r.t the Vehicle Speeds.

dr_nishu2010-12-27 06:55:01

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Hi sham ,ref to ur question i had noticed a switch W /S ( w= winter S=summer )in mercedes S class were in car takes off in 2nd gear in winter snow , There is a possibility as long as your torque band helps ,ex-The torque band in tata vista diesel (fiat engine) is lowered by 250 RPM when compared to same fiat engine of swift , This helps vista in pulling in low RPM as well & in gear speeds

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I do not think there is any problem in doing that as long as the car has enough torque to handle the load without over revving and slipping the clutch.

Our old diesel ambassador had so much torque that it would pull smartly up an incline from standing position with the engine at idle Rpm. Most new cars do not have that kind of torque at those rpm, so while it is best to use all gears when in doubt, if you know what you are doing, its perfectly safe. Just remember to not slip the clutch too much.

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Yes I understand what I'm doing very well..

This is something that was bothering me as there was no clear winner as such..

That being said I would prefer to actually use 1st gear ,simply because even if the torque is ample enough and the gearbox can handle it , 2nd gear is tuned to start from "some speed and inital rpm", its not tuned to kick into action at 0rpm .

This basic and logical point means that there might be issues in the future if the habit of skipping gears is present.

PS:: I"m not too sure.. nothing might happen either.. Logically though i feel discussions till now have been appropriate

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Every gear is designed to operate within a load/rpm range. and more often than not, the high range of the, lets say second gear will overlap with the low range of the fourth even without going into the Factor of safety region. In these cases, in a familiar car, i do not see how skipping a gear can cause any problems.

Most taxiwallas (even those who use their own cars) do it. And in my book, that ts the ultimate test. If a taxi guy does it to his own taxi, its time tested and safe in the long term. Its amazing how the local mechanics and taxi guys find simple jugaad solutions and tricks..We engineers will be amazed at wat can be discovered after a few minutes of chat with a taxi\lorry driver.

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Regarding rpm for gear change, Maruti recommends 2nd gear above 10kph, 3rd gear above 20kph, 4th gear above 30kph and 5th gear(overdrive) above 40kph in the esteem manual IIRC. Most of you will know that practically these speeds are not the best speeds and the engine will appear strained if u shift at these speeds. But the vehicle is built to easily take the strain.

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@Sham

Gearshift is the art which most of the drivers are lacking,maybe me too.Actually my rule is something different,I never do follow the speed,but what I follow is the tachometer(I mean I shift according to RPM or engine speed).

Example:I never shift up below 3500 rpm for 1st,2nd and 3rd gear and below 2500 rpm for the higher gears.This makes the driving a delight for me every time,less wear of clutch etc are bonus points.

So,in my views its best to shift according to the rpms not according to your speed,it really works and works better.

No short-shifts,no long-gear-holdings,its better to shift at a particular rev range,this will also not strain the engine,anywhere and anyway you drive.

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@Joe-ker

You are right,but its a fact that anyone driving a car does not have time to look at the rev counter every time you shift up or down.

So its a matter of the feel,if you have the habit of shifting at a particular rev range then your mind will automatically make you shift by just feeling the engine(I mean sound of the engine and its behavior at the throttle).

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Hi sham ' date='ref to ur question i had noticed a switch W /S ( w= winter S=summer )in mercedes S class were in car takes off in 2nd gear in winter snow [/quote']

 

snow on the road = less friction , nothing to do with gears. the torque generated on the second gear might be enough to start the wheels rolling on a snowy road but wouldn't be sufficient in summer times.

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I think Merc enjoys an automatic transmission as well as an engine that is torquey as well as powerful enough to shake the road...But in terms of a Punto(Have a look at the power to weight ratio).I have even once made my i-10 take off in third gear,methodology is known to everyone...

When it comes to snow,I have driven in snow hundreds of times on my trips to mussoorie,ladakh etc,every time what I have observed is that I am unable to shift higher than second gear,in fact many times even second gear is not engaged,but I stick to my rule of shifting(for hills it is 4500rpm for 1st,2nd and 3rd..4th and 5th gears are never engaged in Innova in hills).

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