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View Poll Results: Which gear gives your car the best pull ahead?
Gear 1 1 0.57%
Gear 2 27 15.43%
Gear 3 109 62.29%
Gear 4 13 7.43%
Gear 5 or above 14 8.00%
Reverse 11 6.29%
Voters: 175. You may not vote on this poll

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Old 2nd July 2018, 11:27   #16
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3rd Gear.
The 3rd gear of Nexon (P) is really tall. It can be used in city and perfect for highway. I am able to drop from 6th at 100 kmph for that enthusiastic overtake 😋
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Old 2nd July 2018, 11:39   #17
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Re: Your favorite gear?

Quote:
Originally Posted by swissknife View Post
Gears that are lesser than a 1:1 ratio are overdrive and not necessarily the last one.
Didn't understand this. Why will there be an overdrive gear in between the other gears ?

The overdrive gear is used to achieve the car's top speed, so if the overdrive is not the last one, which is the gear after that overdrive ? There cannot be an underdrive or direct drive ratio after the overdrive gear because that will be like downshifting even if you are moving up in that gearbox.
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Old 2nd July 2018, 13:52   #18
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Re: Your favorite gear?

Quote:
Originally Posted by OSH View Post
Didn't understand this. Why will there be an overdrive gear in between the other gears ?

The overdrive gear is used to achieve the car's top speed, so if the overdrive is not the last one, which is the gear after that overdrive ? There cannot be an underdrive or direct drive ratio after the overdrive gear because that will be like downshifting even if you are moving up in that gearbox.
Gear ratios are calculated as the ratio between the number of teeth on the driven gear to the drive gear.

For example, take the case below, these are possible ratios for the various gears. In this case, the 4th and 5th are less that 1:1 and hence considered to be "overdrive".

1st - 3.461
2nd - 1.869
3rd - 1.235
4th - 0.948
5th - 0.809
Rev - 3.307

Earlier cars used to come with a separate overdrive knob / levers but not now.
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Old 2nd July 2018, 14:11   #19
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Re: Your favorite gear?

Quote:
Originally Posted by swissknife View Post
For example, take the case below, these are possible ratios for the various gears. In this case, the 4th and 5th are less that 1:1 and hence considered to be "overdrive".

1st - 3.461
2nd - 1.869
3rd - 1.235
4th - 0.948
5th - 0.809
Rev - 3.307
Shouldn't the 4th gear in your example be 1.000 i.e. direct drive ?

Even in your example, the last gear is still the overdrive gear. Your first post said that overdrive need not necessarily be the last one.

My point was that if a car is getting an overdrive gear, the last gear HAS to be overdrive and overdrive cannot come in between the other gears.
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Old 2nd July 2018, 14:13   #20
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Re: Your favorite gear?

Quote:
Originally Posted by OSH View Post
Both; 4th-5th gear or 5th-6th gear of the same car cannot be overdrive gears, AFAIK there can only be one overdrive gear and that is the last gear. So if the the car has 5 forward gears, the 5th gear is overdrive and if the car has 6 forward gears, 6th gear is overdrive.

The gear just before the overdrive gear will be the direct drive; 4th gear in case of cars having 5 forward gears and 5th gear in cars having 6 forward gears.
Though I am not an expert on this topic, I would like to highlight few examples that I remember, where (in case of 6 speed transmission) both 5th & 6th gears are overdrive :

1. Tata Nexon [posted here on Team-BHP]

Your favorite gear?-tata-nexon.jpg

2. Hyundai Elantra (Australia) [Link]

Your favorite gear?-elantra-australia.jpg

3. Hyundai i30 (Australia) [Link]

Your favorite gear?-i30-australia.jpg

Infact, if we look closely, 4th Gear in Tata Nexon and i30 1.6 CRDI is more like overdrive rather than a direct drive. I also remember that ratio figures for Hyundai Elite i20, Hyundai Creta, Suzuki S-Cross (1.6 DDIS - 320Nm) have two overdrive gears, but can't find reference as of now.

So, IMHO, its more to do with the driveability and engine tuning (for FE etc.) to decide upon gear ratios, rather than thumb rule of only one overdrive gear in a transmission.
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Old 2nd July 2018, 14:22   #21
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Re: Your favorite gear?

Voted for reverse! Sometimes I feel the pull 'behind' is thrilling when you blip the throttle in reverse gear.. Maybe it can be the directional switch, but exciting nevertheless.
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Old 2nd July 2018, 14:37   #22
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Re: Your favorite gear?

Quote:
Originally Posted by AutoNoob View Post
I would like to highlight few examples that I remember, where (in case of 6 speed transmission) both 5th & 6th gears are overdrive
Wow ! Thanks for pointing this out. I never knew that these guys skip the direct drive ratio in their 6 speed gearboxes and provide two overdrive gears instead. I used to think that a 1:1 ratio is compulsory.
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Old 2nd July 2018, 15:07   #23
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Re: Your favorite gear?

Quote:
Originally Posted by OSH View Post
Wow ! Thanks for pointing this out. I never knew that these guys skip the direct drive ratio in their 6 speed gearboxes and provide two overdrive gears instead. I used to think that a 1:1 ratio is compulsory.
One more thing, it is not mandatory to have exact 1:1 ratio (direct drive) in a transmission. Selection of gear ratios depends on lot many factors including transmission shaft/ gear packaging, manufacturing feasibility in addition to what I mentioned in my previous post.

Direct drive ratio is more common in longitudinal transmission layouts.

In the meantime, I was able to get hold of Suzuki SX4 S-Cross transmission ratios from their Hungary website [Link]. Its in Hungarian, but specs can be understood. I believe the D16AA engine and transmission combination is same as what was available in Indian S-Cross (it was imported from FIAT Europe).

Your favorite gear?-suzuki-sx4-scross_hungary.jpg

Here also, we can observe that even in 5MT versions (K10C Boosterjet), both 4th & 5th gears are overdrive.

Last edited by AutoNoob : 2nd July 2018 at 15:10. Reason: added about K10C Boosterjet 5MT
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Old 2nd July 2018, 15:13   #24
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Re: Your favorite gear?

It is really difficult to think what a favourite gear is. It depends on the car and the circumstances. In my favourite car, my Alfa Romeo Spider it tends to be 2nd/3rd. Plenty of acceleration, high revs, good engine braking and a great sound track. But as soon as I hit the motorway it goes into 5th.

On the subject of overdrive: there are various definitions floating around, but it comes down to a simple concept: If the output shaft speed is higher than the input shaft speed, this is considered overdrive. If they are equal it is considered "direct drive".

Subsequently you might also see the term underdrive. Which means the input shaft rotates faster than the output shaft.

Overdrive was a big thing on older cars. Today we would call them vintage or classic cars. Lots of older cars had a top gear ratio of more than 1, maybe 1:1.1. which meant the car would accelerate well, but it would not cruise efficiently. Remember, engine torque in those days was vastly different from current engines. Overdrive meant you could get better fuel economy whilst cruising and also important, it really meant a lot less engine noise as well. Typically the overdrive was engaged by the flick of a switch.

These type of overdrives were basically an additionally gear kit (the overdrive unit) that got bolted onto the existing gearbox.

These days we have much more powerful (torgue) engines and we have gearboxes with 5, 6, sometimes 8 or more gears on saloons cars. But that is all within the same gear box.

So whilst technically anything that gives you less than a direct drive (1:1) is considered an overdrive by definition, in practical terms it is very different from what an overdrive (unit) used to be.

Because it was a bolt on box, there are variants where you can engage overdrive in multiple gears. Although still called overdrive it might not mean a less than 1:1 ratio. In fact it means you might have a sort of intermediate gear. For instance on many old British cars you will find an overdrive that could be engaged in both 3rd and 4th gear. Only in 4th gear it would be a true overdrive. The same principle still applies to some gearboxes you would find on trucks or lorries. They might have say 8 normal gears and an intermediate gear for each. Sometimes they might call it overdrive. It's just to get the most optimum torque at different speeds and weights at all times

Jeroen

Last edited by Rehaan : 3rd July 2018 at 17:34. Reason: Correcting a few typos :)
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Old 2nd July 2018, 15:27   #25
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Re: Your favorite gear?

Quote:
Originally Posted by OSH View Post
Shouldn't the 4th gear in your example be 1.000 i.e. direct drive ?

Even in your example, the last gear is still the overdrive gear. Your first post said that overdrive need not necessarily be the last one.

My point was that if a car is getting an overdrive gear, the last gear HAS to be overdrive and overdrive cannot come in between the other gears.
I think a lot has been said discussed about the overdrive and I hope there is clarity now.

As said, a direct drive 1:1 is not necessary. Any ratio that is less than 1 could be considered to be an overdrive, not only the last one. Overdrive may however be different in context than what it was referred to in years gone by.

I guess we had digressed while, but I think it has also helped in clearing out ambiguities.
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Old 2nd July 2018, 15:50   #26
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Re: Your favorite gear?

Ah! The old times.
We used to have Maruti Suzuki Esteem (2003-2010) with 1.3 liter mpfi engine. That crazy car with its 85 Bhp had a power to weight ratio of around 98bhp per ton coupled with extremely tall gears.
The 2nd gear went from 20 Kmph all the way till 100 Kmph ! The 3rd gear went all the way till 150 Kmph ! 4th and 5th were pretty much useless.

There was a similar case with Baleno of those years as well.

I remember clearly that Esteem used to pip Baleno in the race to 100 Kmph because in case of Baleno the 2nd gear maxed out at 96 Kmph forcing the Baleno driver to hit the rev limiter and up shift just before hitting the ton and thus leaving them red faced
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Old 2nd July 2018, 15:52   #27
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Re: Your favorite gear?

My favourite gear?

Hmmmmmm...

Almost always one below what most others would be at!
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Old 2nd July 2018, 16:31   #28
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Re: Your favorite gear?

Should 'neutral' not be an option too? Especially as we go downhill.

I wonder what we are going to do after a lot of people are done with the voting.
Make it the default starting gear? or say that second gear is the top gear?

Of the available options, I like the reverse gear (think Tow Mater from Cars)
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Old 2nd July 2018, 16:33   #29
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Re: Your favorite gear?

I feel this is pointless - each car with a different engine will ideally have a gearbox designed and developed for it. The same gear box could be used in different cars and made to behave entirely differently. In an engine with a wide torque band you will have short first, second gears, a versatile third, an almost equivalent fourth and fifth/sixth etc etc overdrive. The same gearbox in a different car with a short torque band will be made to work differently!

Last edited by GTO : 3rd July 2018 at 08:24. Reason: Last lines were too rude
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Old 2nd July 2018, 18:14   #30
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Quote:
Originally Posted by fuelinmyveins View Post
Ah! The old times.
We used to have Maruti Suzuki Esteem (2003-2010) with 1.3 liter mpfi engine. That crazy car with its 85 Bhp had a power to weight ratio of around 98bhp per ton coupled with extremely tall gears.
The 2nd gear went from 20 Kmph all the way till 100 Kmph ! The 3rd gear went all the way till 150 Kmph ! 4th and 5th were pretty much useless.
I remember clearly that Esteem used to pip Baleno in the race to 100 Kmph because in case of Baleno the 2nd gear maxed out at 96 Kmph
We had an Esteem with the same and man it was fun. That car tought me driving and the meaning of FTD.
We still have the Baleno which we got after the Eateem got retired. It's an invincible workhorse. Typical Japanese engineering. Light, fun and so so durable. It's a Corolla from Suzuki.
For your pleasure:
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