4 Speed Automatic vs 5 or 7 Speed

[Kazuo]

Is 4 speed more torquey but heavier fuel consumption compare to 5 or 7 speed?

 

Or it lose out in all aspect?

[ER-3682]

  On 3/31/2012 at 2:41 PM, Kazuo said:

Is 4 speed more torquey but heavier fuel consumption compare to 5 or 7 speed?

 

Or it lose out in all aspect?

Of course more speeds the better,saves fuel,faster pick up,etc.

[Lohkyx]

any set of gear at 1 is torquey but u just end up losing more power

[Kazuo]

  On 3/31/2012 at 3:41 PM, Lohkyx said:

any set of gear at 1 is torquey but u just end up losing more power

 

How is that so?

[Blackyv]

  On 3/31/2012 at 2:41 PM, Kazuo said:

Is 4 speed more torquey but heavier fuel consumption compare to 5 or 7 speed?

 

Or it lose out in all aspect?

 

Maybe the only saving grace of 4 speed is the repairing cost...should be cheaper right?...

[Lohkyx]

  On 3/31/2012 at 4:01 PM, Kazuo said:

How is that so?

 

same like cycling

[Cklasse]

I had the 5 speed C-class and recently changed to the 7 speed C-class. There is a difference in performance; picking up is faster and smoother (my tacho rpm never exceeds 3000rpm), merging into expressway is seamlessly smooth. One more good thing about this 7gtronic, it knows the car is going down steep incline and will hold the gear automatically without shifting up.

 

 

[Coupecabriolet]

  On 3/31/2012 at 4:53 PM, Cklasse said:

I had the 5 speed C-class and recently changed to the 7 speed C-class. There is a difference in performance; picking up is faster and smoother (my tacho rpm never exceeds 3000rpm), merging into expressway is seamlessly smooth. One more good thing about this 7gtronic, it knows the car is going down steep incline and will hold the gear automatically without shifting up.

 

7G tronic is really a step up. the old 5AT in mercs is really slow shifting and constantly in a dilemma, duno which gear to hunt for. and if the driver suay suay hard accelerate after a gear has just been shifted, that's it, no power and big turbo lag.

 

my DSG no such problem.

 

but i like BMW's 8 speed gearbox too.. that is really seamless.

[Mecontle]

too many gear & it become stupid , 5 for manual 6-7 for auto s fine

[Kazuo]

Grand Vitara is one heavy vehicle running on 4 speed automatic.

There has to be some benefit in it?

 

I mean, it seems that Suzuki choose to keep it at 4 speed instead of

5 or 6, not because of technological limitation.

[Beng2]

More speed is better in my opinion (but not CVT hor). The gear ratio can be spread more closely. For example, when climbing hilly road with a 6-speeder, the gear may only need to be in 2nd if it's not too steep. The drop from 3rd to 2nd is also much smoother. On a 4-speeder, the gear may have to be dropped to first - creating jerks. When overtaking, the car needs to drop from 6th to 5th instead of 4th to 3rd (more transmission jerk).

 

Lastly, the final drive is more economical due to lower RPM.

 

  On 3/31/2012 at 5:26 PM, Kazuo said:

Grand Vitara is one heavy vehicle running on 4 speed automatic.

There has to be some benefit in it?

 

I mean, it seems that Suzuki choose to keep it at 4 speed instead of

5 or 6, not because of technological limitation.

Cut cost la.. no need to upgrade the gearbox.

[JaydenSTI]

  On 3/31/2012 at 2:41 PM, Kazuo said:

Is 4 speed more torquey but heavier fuel consumption compare to 5 or 7 speed?

 

Or it lose out in all aspect?

 

 

The thing is the lower the ratio between crank gear and drive gear the less torquey u feel. Normally more drive gears you have more freedom in selecting your ratio (for gear box designer though.....) thus easier in making a feel of more torquey. However, if I have an outrages first gear with super high ratio on gear 1, but super long gear ratio on gear 4, this 4 speeder will still make you feel torquey on gear 1, but take you forever to build speed on gear 4...... So, no absolute answer to your question.....

[JaydenSTI]

  On 3/31/2012 at 5:43 PM, Beng2 said:

More speed is better in my opinion (but not CVT hor). The gear ratio can be spread more closely. For example, when climbing hilly road with a 6-speeder, the gear may only need to be in 2nd if it's not too steep. The drop from 3rd to 2nd is also much smoother. On a 4-speeder, the gear may have to be dropped to first - creating jerks. When overtaking, the car needs to drop from 6th to 5th instead of 4th to 3rd (more transmission jerk).

 

Lastly, the final drive is more economical due to lower RPM.

 

 

Cut cost la.. no need to upgrade the gearbox.

 

Well, if some brilliant engineer came out with some super AI, the CVT will be way to go!!! No fix gears can always stay at the peak power of any current engine at all time but CVT. Till then close ratio would still shine.

[Happily1986]

  On 3/31/2012 at 5:52 PM, JaydenSTI said:

The thing is the lower the ratio between crank gear and drive gear the less torquey u feel. Normally more drive gears you have more freedom in selecting your ratio (for gear box designer though.....) thus easier in making a feel of more torquey. However, if I have an outrages first gear with super high ratio on gear 1, but super long gear ratio on gear 4, this 4 speeder will still make you feel torquey on gear 1, but take you forever to build speed on gear 4...... So, no absolute answer to your question.....

 

Normally the industry refer to and describe gear ratio as being "short or long". when you look at the tachometer, gearboxes that have been set up for short gear ratios are such that you will see a very slight dip in rpm when you upshift. For those gearboxes that are engineered for long gear ratios, you will see that the dip is very drastic. As such, short gear ratios offers better pick up because the gearbox keeps the engine running in the optimal engine rev zone instead of letting the engine whittle down to a much "sedate" rpm region.

 

if you set up the gear box for short gear ratios, the problem is the final gear ratio. Will it be too short? That will limit the top speed.

 

if you set up the gear box for tall gear ratios, in general, fuel consumption should be better but pick up is crappy.

[Yewheng]

  On 3/31/2012 at 5:57 PM, JaydenSTI said:

Well, if some brilliant engineer came out with some super AI, the CVT will be way to go!!! No fix gears can always stay at the peak power of any current engine at all time but CVT. Till then close ratio would still shine.

 

Yeah. I like driving CVT. Very smooth drive, drive uphill genting quite a pleasure. I never driven 6 or 7 speed before so I not too sure whether it can beat the smoothness especially when going up and downhill.

[JaydenSTI]

  On 3/31/2012 at 6:12 PM, Happily1986 said:

Normally the industry refer to and describe gear ratio as being "short or long". when you look at the tachometer, gearboxes that have been set up for short gear ratios are such that you will see a very slight dip in rpm when you upshift. For those gearboxes that are engineered for long gear ratios, you will see that the dip is very drastic. As such, short gear ratios offers better pick up because the gearbox keeps the engine running in the optimal engine rev zone instead of letting the engine whittle down to a much "sedate" rpm region.

 

if you set up the gear box for short gear ratios, the problem is the final gear ratio. Will it be too short? That will limit the top speed.

 

if you set up the gear box for tall gear ratios, in general, fuel consumption should be better but pick up is crappy.

 

True enough.

 

My previous car with 5 speeders had a much taller ratio which can reach 300+ kph if the engine able to sustain at redline, but my current 6 speeders had a very close ratio that my theoretical final speed at redline on 6 gear can reach only 297kph (never been there and will never reach there.....)

 

But, nothing beat the close ratio box that provide the driving pleasure than any other car that I have driven before! Drive it hard, no gear change will drop less than 4k rpm.

 

 

[Hondafit2008]

many ppl disappointed with jap car maker is also they still die die wanna use 4 speed. just to save some money from the profit. look at subaru. FI liao still die die 4 speed

[Thedream]

  On 4/1/2012 at 1:16 AM, Hondafit2008 said:

many ppl disappointed with jap car maker is also they still die die wanna use 4 speed. just to save some money from the profit. look at subaru. FI liao still die die 4 speed

 

i think for a few years now the automatics from subaru are 5-speed.