5 Speed or 6 speed, Whats the difference?

Fearless Leader

macrumors 68020
Original poster
Mar 21, 2006
2,360
0
Hoosiertown
I can't seem to find an answer other than HUH? or 1 gear. I can look at the gear ratios but I'm not entirely sure how that equates to actual driving. Can someone give me a good answer? what the advantag? cause the 6 speeds I looked at just had a little higher gear ratio in first but 6th and 5th were the same.
 

iGav

macrumors G3
Mar 9, 2002
9,025
1
It can often be related to something like torque for example, a car with good torque often doesn't require more gears because you'll lose time through changing, or gain no benefit in other words.

Or a car with comparatively little torque can benefit from an increased ratio range.

Sometimes 6th (or 7th) is used as an overdrive so that the previous gears can be narrower to allow increased acceleration (and thus performance) in the lower gears, but still be able to obtain motorway speeds whilst achieving double digit economy figures. :p
 

Rodimus Prime

macrumors G4
Oct 9, 2006
10,136
4
the top gear (5th or 6th) will have the same gear ratio. The differnce is there are more gears in the 6th speed. This allows them to be a little closer together.

I drive a 6 speed. I can tell you part of the reason my care has a 6 speed was it was marketing (more than likely a huge part) but it does allow all my gears to be a little closer together. It a close ratio gear box and this allows me to stay in the power band more easily.

The difference I noticed between my older 5 speed and my 6 speed now is where the shift points on at red line.

On the 5 speed it was
25, 60,90 (I I believe in 4th I would run out of horse power before I top it off) those numbers where the same on my dad 5 speed manual as well and they where different makes of cars

My current 6 speed
20,50,75,110 (I think only did it once and it been a while)

If you noticed each of the first 3 gears have about 5mph less range than the 5 speed so it starts adding up. But at the same time if I run it to red line I and I shift I stay in a slightly stronger part of my power band. Not like that 5mph makes much of a difference.

Lastly come on 6 speed is just cooler. I will say in actional daily driving it really does not do much. Means I may have one extra. It nice when I need the extra power to just drop it to 5th at highway speeds but then again my car has a lot of low end torque for a sporty 4 banger.

I hope this long answer answers your question.
 

Lord Blackadder

macrumors G5
May 7, 2004
13,697
2,724
Sod off
It can often be related to something like torque for example, a car with good torque often doesn't require more gears because you'll lose time through changing, or gain no benefit in other words.

Or a car with comparatively little torque can benefit from an increased ratio range.
Which is why some American musclecars, with very torquey engines, had 3 speed (or even 2 speed) transmissions...and also why Honda was an early adopter of five and six speed transmissions.

Sometimes 6th (or 7th) is used as an overdrive so that the previous gears can be narrower to allow increased acceleration (and thus performance) in the lower gears, but still be able to obtain motorway speeds whilst achieving double digit economy figures. :p
I've noticed that cars with a six speed often do have a very tall 6th gear - useful only for highway cruising. I once drove an Acura (Honda) Integra GS, and the 6th gear seemed way too tall, though it probably was very good for fuel economy.
 

Rodimus Prime

macrumors G4
Oct 9, 2006
10,136
4
I've noticed that cars with a six speed often do have a very tall 6th gear - useful only for highway cruising. I once drove an Acura (Honda) Integra GS, and the 6th gear seemed way too tall, though it probably was very good for fuel economy.
Yeah I noticed any 6 speed car I been in the 6th gear is a little tall. But then again it is like Overdrive on an automatic. Only useful for highway cruising.
Now Honda/Acrura engines have crap for low in torque. There is a reason why things like the S2000 unless you drive it like you stole it is just picks up very slowly.

Cars with a fair amount of low end torque have enough mussel to be able to do minor passing power in 6th gear. On my Sentra Spec V has a lot of low end torque and at high way speed (70mph) it will be around the bottom side of it where it enters it power band (3k) but even down to 2k it has quite a bit of gusto.

But like you point out if the car power band is very narrow and very top end the tall overdrive gear means no power beside cruising speed
 

Lord Blackadder

macrumors G5
May 7, 2004
13,697
2,724
Sod off
One thing to keep in mind is that you need to look at a car from a holistic perspective - the engine/drivetrain must be well matched, and that combination must be mated to the appropriate chassis to produce the best possible car.

5 speed gearboxes are not inherently inferior to 6 speeds. Well-chosen gear ratios matter far more than the number of gears in a drivetrain. Also, a transmission might have excellent ratios, but have a crappy linkage that sucks to operate, so it's a more complex question than the number of gear ratios.
 

iGav

macrumors G3
Mar 9, 2002
9,025
1
i believe that applies to all cars.
It's all relative, an average TDi has a torque peak often between 1500-4000rpm, a marked difference from a Honda VTEC for example so there's no need to rev a TDi as aggressively, in fact it's often to the detriment of performance if you do.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
25
Right side of wrong
It's all relative, an average TDi has a torque peak often between 1500-4000rpm, a marked difference from a Honda VTEC for example so there's no need to rev a TDi as aggressively, in fact it's often to the detriment of performance if you do.
but for most cars you get the max horsepower at the higher RPMs. give me a link that says otherwise?
 

Lord Blackadder

macrumors G5
May 7, 2004
13,697
2,724
Sod off
but for most cars you get the max horsepower at the higher RPMs. give me a link that says otherwise?
Not for diesels. And while it is true that maximum power often occurs at higher rpms, an engine with a flat torque curve doesn't necessarily need to rev that high even when driving flat out, since it might make 90% of it's power and 100% of its torque at just 70-80% max rpm. The Honda engines tend to make all their power and torque around 6-7k rpm.
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
25
Right side of wrong
Not for diesels. And while it is true that maximum power often occurs at higher rpms, an engine with a flat torque curve doesn't necessarily need to rev that high even when driving flat out, since it might make 90% of it's power and 100% of its torque at just 70-80% max rpm. The Honda engines tend to make all their power and torque around 6-7k rpm.
give me a diesel with a 6-speed transmission?

even at 60-70% max, that's still pretty high
 

Sdashiki

macrumors 68040
Aug 11, 2005
3,512
8
Behind the lens
but for most cars you get the max horsepower at the higher RPMs. give me a link that says otherwise?
Vtec typically doesnt kick in until the last 1500rpm before red line.

So, it stands to reason you gotta really get the rpms up before a Honda/Acura really gets going.

Sit in a Civic SI, take it to the highway onramp in 3rd gear, when you are about to shift to 4th, keep holding the gas steady, watch when it hits near 1500 under redline the burst of acceleration Vtec gives you.
 

devilot

Moderator emeritus
May 1, 2005
15,588
1
I've noticed that cars with a six speed often do have a very tall 6th gear - useful only for highway cruising.
Yup. 6-speed Getrag tranny in my CooperS, and as you say, last gear is useless (performance-wise).

And I agree, all depends on powerband. Higher RPMs does NOT always mean more power.
 

sammich

macrumors 601
Sep 26, 2006
4,285
215
Sarcasmville.
give me a diesel with a 6-speed transmission?

even at 60-70% max, that's still pretty high
The entire Diesel range for Land Rover?

Which by the way when cruising at 110km/h (~68mph) in 6th gear is running at roughly 1200-1400 rpm, seriously low, but then again it redlines at about 4000rpm i think.

In petrol cars, higher RPM generally means more power, since (again, as a rule of thumb) Power = torque x revs. But higher revs has more losses etc. In a diesel engine, the torque band comes in really early and fairly large, meaning low power (low rpms). Low rpms is more efficient. That is why loads of torque early on is good for pulling heavy stuff.
 

garybUK

Guest
Jun 3, 2002
1,466
2
My Audi A3 2.0ltr TDI has 6 gears, very low revs at ~90mph, i can still drop it to 5th to pull away (over taking etc).
 

twoodcc

macrumors P6
Feb 3, 2005
15,307
25
Right side of wrong
The entire Diesel range for Land Rover?

Which by the way when cruising at 110km/h (~68mph) in 6th gear is running at roughly 1200-1400 rpm, seriously low, but then again it redlines at about 4000rpm i think.

In petrol cars, higher RPM generally means more power, since (again, as a rule of thumb) Power = torque x revs. But higher revs has more losses etc. In a diesel engine, the torque band comes in really early and fairly large, meaning low power (low rpms). Low rpms is more efficient. That is why loads of torque early on is good for pulling heavy stuff.
thanks for that, and i agree with you here. that makes sense.

and again, higher RPMs usually equal more power.

sorry, some people make statements without explaining it. (including myself)

My Audi A3 2.0ltr TDI has 6 gears, very low revs at ~90mph, i can still drop it to 5th to pull away (over taking etc).
and when you drop it to 5th, the RPMs go up, giving you more power! ha!
 
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