In my experience, that's the case with almost all six-speed boxes in relatively mundane cars. Even some five-speeds are the same (or the converse) - I have no wish for a sixth gear, but it'd be nice if 5th was 20% higher.

Well, 330i isn't exactly mundane as you've put it, but I can see you do understand what I mean by saying 6 gears can be pointless.

that's a really, really odd comment. you're saying the ratios between the gears on "mundane" cars are different to more exotic cars? they really aren't, it's just the diff that's different in reality (ok the ratios are different but the margins aren't that much.

what happens say if the engine is cold and you don't want to go above 3000rpm but don't want the engine to labour. you join the motorway, hit say 2800rpm rpm in 4th then go to change into 5th and then suddenly you're at less than 2000rpm where the engine may be labouring....you think that's better than going from say 2800rpm, then down to 2400rpm, back up gently to 2800rpm again and then into a 6th.

that's just 1 scenario but you get the point. having more ratios, well spaced is better than less ratios with the same spacing for the 1st few gears and then a huge jump to the last gear. it just is.

Who cares what the actual ratios in the box are? It's the final drive ratio of each gear that matters, unless you sit there counting how many times your prop shaft has gone 'round. If you're going to cruise at 200mph, I can certainly see the point in having 7 gears to get there; if your car has a top speed of 120, I can't really see the point in having more than five, to be honest.

When the engine is cold and I don't want to go above 3000rpm, I also don't want to use more than about 1/3 throttle either, so generally I just drive slowly. My engine is warm before I can get to the nearest dual carriageway.

No I don't, I care what the final drive ratios in each gear are. I want fifth gear to be taller - I couldn't care less whether that's by making fifth gear longer or by making every other gear shorter and changing the diff; I wouldn't even be able to tell the difference between the two approaches.

I'm by no means saying there aren't some advantages to having more gears; just that I believe they are outweighed by the disadvantages. Obviously from a purely theoretical standpoint, a CVT is the perfect solution, although I don't know how you'd set up the control mechanism. From a purely theoretical standpoint though, any kind of manual control is rather pointless.

[dibnah]


Bl**dy kids of t'day, with you're poncy multispeed transmissions, don't know when you're born you lot do yoooou. In mi day we only had 2 speeds, and non of that unecessary new fangled synchromesh gubbins neither. Twooooo gears, soo difficult to drive you'd often be competely killed to death just attempting to pick up missis from t'Bingo of an evenin. but, bi eck, when you got it just right like, son, let me tell you, t were like that colliery bass band hitting the high notes in perfect time, music to a workin mans ears, grand it were, grand! 'course, it were all just solid brass in my day, none of that silicon carbide nonsense neither...........


[/dibnah]



;-)

if you made every other gear shorter and changed the diff so 1st 4 gears were shorter but 5th was taller then you're still changing 5th gear ratio. if you want a taller 5th and do so by NOT altering any of the ratios other than the diff, all gears would be taller. so the ways you've mentioned you'd still be changing a single gear ratio......which you said you don't care for.

Kambites, do you ever use 4th or do you go from 3rd to 5th? Your car would pull it and be ok but it's not ideal in all scenarios. If on a dual carriageway and you have 6th then you hit a hill dropping to 5th would be more preferable to straight to 4th, for instance.

You can't make just 5th taller without changing that specific ratio as you know, so why you mentioned the diff ratio is don't know?

Most cars don't need the top speed many posses so why not just reduce maximum speed to maybe 100-110 mph and then have six appropriate ratios, surely we would then be fine with six.

Super cars maybe an exception but does my 2.0 tdi golf really need to be capable of 140 mph??

Do you really want to be cruising on the motorway at 5000rpm?

VW used to do a 5-speed box they called the 4+E which had 4 driving gears then a very long top gear to drop the revs on the motorway which sounds like what kambites needs.