5 speed vs 6 speed?

[Frank Lee]

Yeah, I know it isn't a universal solution what with hills and towing and most importantly the Stop Light Gran Prix that others contend with. But as a flat-lander with a Tempo and it's torquey, low-rpm tractor engine a 3-speed m/t would suit me just fine and I'd expect an fe bump to boot. Make it a three-on-the-tree to free up interior space and I'd really have something!

[oil pan 4]

OE ratios are fairly spaced out. The only transmissions I have seen with a wider or narrower than OE range of gears are autos, for racing.

[JockoT]

My UK spec Jazz/Fit has a 5th gear ratio of 0.805 and a final drive of 4.111. It would certainly benefit from a taller 6th gear. I have often went to change, thinking I was in 3rd when I was in fact in 5th.

[Xist]

"Stop Light Gran Prix!" I love it!

[KrautBurner]

Originally Posted by bratboy

hey folks, I just joined and this is a first time post. I had a question about manual transmissions. Over the years I've seen more gears pop up in transmissions. Assuming the final drive ratios are the same and the lower and upper gears are the same...is there much fuel savings between a 5 speed and 6 speed manual?

it really depends on the car

back in the 80's
VW did the Rabitt with the 4 speed and 5 speed (GTi)
in the 4 speed, 4th is a 0.94:1 ratio
in the 5 speed, 4th is a 1.03 and 5th is a .84

many people would say that with that little OD
the 4 speeds will get better fuel economy unless you spend ALOT of your time cruising at highway speeds


the mustangs and Camaros with 5 speeds had a
1:1 4th gear and a .84:1 5th

the 6 speed cars had the same 4th and 5th and added the "double overdrive" of .57:1 for the 6th


this makes a huge difference as long as your engine produces enough torque down low
and you can keep your speed up

my 2005 GTO (400hp/tq stock) got a solid 30mpg if I kept the speed between 70-75mph and don't make any stops


many of the newer economy cars with 6 speed transmissions
just make the gears closer together and the OD is still close to .85:1

[cRiPpLe_rOoStEr]

Originally Posted by Frank Lee

Make it a three-on-the-tree to free up interior space and I'd really have something!

I still consider 4-speed enough for most uses, but a three-on-the-tree wouldn't be so bad.

[bratboy]

So I'm right back where I started...lol

[cRiPpLe_rOoStEr]

Originally Posted by bratboy

So I'm right back where I started...lol

Most likely you won't get any actual benefit from the 6-speed instead of the 5-speed anyway.

[BLSTIC]

W*** Factor (or more politically correct "Impression Ratio") increases with a 6-speed however...

[bratboy]

I've been doing a bunch of reading since I posted this and from what I read and what I saw in a couple of the posts here I think the extra gears do you help. The point is to stay in the low RPM range as much as possible and extra gears help you do that. I can't see how a 3-speed automatic is going to be better for fuel economy then a 5-speed so to speak. And I don't think the gears are being added to automatic transmissions for the wow factor. I think they're actually is a difference in the fuel economy they bring. One of the best ways to find out because of everything being equal except for one thing would be a Saab 9-3 small t Turbo. They have a 5-speed but you can retrofit them with a six-speed. That'd be really interesting to do in to see what the difference was fuel economy because from what I remember everything is the same in terms of a final drive, first year, and Top Gear's. But I don't think anybody's ever going to test this out extensively