As far as I know and I'm not an engineer, the primary difference is the 6th gear is basically your 'overdrive'. At higher speeds, your RPMs will be lower with the 6 speed. I had a 5 speed '00 323ci and now have the 6 speed '04 330ci...only difference is that. The speed per gear is basically unchanged.

 

Im sure you fanatics know that the facelift 330ci is equiped with a 6 speed tranmissions instead of the 5 speed. I'm just wondering what are the advantage of having a 6 speed versus 5 speed, if any and what are the difference. The only experience i have with a manuel transmission is my friend's 95 avus blue m3.

Thanks you fanatics

Allows for a meaner 1-5 gearing and increase in acceleration (if geared to do so like the ZHP pack). The 6th gear is just about the same as 5th on a 5 speed. May a little more RPM hungry.

 

The length of each gear might be a little shorter too, which means that you might have to shift out of first into second a little bit sooner, but i regret not having waited for the 6 speed so I could crise at 100mph at a much lower rpm, saving gas.

 

Actually, there is probably very little difference in gearing. 1-5 are probably close to the same as 1-5 on the 5-speed. Only difference is that BMW 6-speeds have that 6th overdrive gear, even on the M3.

That's what so cool about BMW 5-speeds, the 5th is a direct drive, just like gear 5 on the 6-speed. So performance-wise, there is virtually no difference. High speed cruising is nicer with the 6.

 

yup. gears 1-5 are the same, the 6 speed gives you an overdrive. 5th on the 5 speeds is 1-1. that being said, better gas mileage due to lower rpm's when cruising and a higher rear end gear (lower numerically) 5 speed cars have a 3.15 rear and the 6 speed has a 2.93 rear. the 6th. gear is a .85 ratio. top speed remains at 128 however for both except for the ZHP model which I believe is raised to 155. gears 1-5 on both 5 spds and 6 spds are identical. it's on the bmw website guys..

 

yup. gears 1-5 are the same, the 6 speed gives you an overdrive. 5th on the 5 speeds is 1-1. that being said, better gas mileage due to lower rpm's when cruising and a higher rear end gear (lower numerically) 5 speed cars have a 3.15 rear and the 6 speed has a 2.93 rear. the 6th. gear is a .85 ratio. top speed remains at 128 however for both except for the ZHP model which I believe is raised to 155.

That's interesting.. I was making an assumption on the gearing ratio's only b/c I wondered how in the hell you can get 1/2 sec better 0-60 times from just 10hp? If i'm not mistaken, isn't the normal 330 like 0-60 in 6.4?

 

Well, the .5 sec difference comes from the rear diff.

 

well, not exactly identical, but close enough where you won't get any real differences. 5 speed
4.23/2.52/1.66/1.22/1.00
6 speed is
4.35/2.50/1.66/1.23/1.00/.85

these differences will not get you a noticeable diff. in acceleration.

 

I beg to differ, having driven/owned more than my share of 5speed BMW 3 series, my new 6speed ZHP is different enough to warrant consideration by anyone wanting more performance out of a 3 series. Yes 1st to 2nd is a much quicker change. In fact, I find that 1st gear revs way too high to be useful, whereas I wouldn't need to shift out of 1st while getting out of my townhouse complex, in the ZHP I am in 2nd gear soon after I pull out of my spot. Weight difference is nominal. On the highway, the 6speed shifts are much more crisp due in part to the ZHP short shift but also because the powerband of the car is better divided amonst the first 5 gears. You really do get a better feel about what gear you should be in just by how the car is pulling and yes 6th gear is the overdrive, just leave it there on the highway gear like 5th was on the 5speed. I see why BMW put the 6speed in the performance package, and why m3 and m5 drivers have been enjoying them for a while now. IMO perhaps the 325s do not need it as much, but once they started prodution of the 225 HP 330i and now the 235 HP ZHP -- it was little time before they probably started thinking about putting 6speeds in them to better manage that extra HP and get it to the wheels. OH yeah SMG is hot too.

 

No, we're talking about two different things. The reason your ZHP is quicker is because of the rear diff, not the transmission. You could argue that the extra headroom in gear 6 allowed BMW to use a lower diff, but that's not necessarily true. For instance, they could easily put a 6-speed in all other 330s and unless they also change the diff, those other 330s won't be as quick as your ZHP.

Or, another example, if I took my 6-speed out of my M3 and replaced it with a similar 5-speed, the car would not be any slower 0-60.

 

well, not exactly identical, but close enough where you won't get any real differences. 5 speed
4.23/2.52/1.66/1.22/1.00
6 speed is
4.35/2.50/1.66/1.23/1.00/.85

these differences will not get you a noticeable diff. in acceleration.

Given that there are gearing changes and final drive is shorter, you WILL notice a difference in acceleration and it seems to be to a .5 second difference. 1st in the 6 speed is taller thus giving greater pull off the line to get the mass moving, 2nd is a bit longer than the 5 speed 2nd but that compensates for the longer 1st gear and allows the vehicle to get to 60-62mph without having to do a second shift. That's very important for magazine racing as the 0-60, 0-62mph rating helps sell cars.

The .85 is pretty sweet as I'm sure it makes cruising a quieter smoother experience. I wouldn't use 6th unless I were going over 65mph though.
That lower final drive quickens the car.

TT

 

I didn't know about the rear diff.. thanks for the info though!

 

The 6th gear is great, at about 90mph you're turning under 3000 rpm and at 100mph it's barely over 3000rpm. In 5th it's considerably higher, about 4k for 90mph. I can't remember 5th for sure, but it's quite a bit faster on engine speeds.

I don't use 6th except when I know I'll be going 70 or faster. Otherwise it doesn't seem to have enough punch to get out of trouble like I would have in 5th. When going 70+ you can leave it in 6th, you get plenty of power.