What does 6th gear do that 5th doesnt?
- Thread starter andysat
- Start date
Bit of a sweeping generalisation here, but in the Z4 specifically gears 2-5 are slightly shorter and the 6th gear is longer than 5th on the 5-speed box.
What does this mean? It means that when cruising at 50mph+, the 6th gear is revving the engine less. In general terms this means less fuel usage and a quieter, less used engine.
The shorter earlier gears allow for quicker acceleration to some degree due to the fact there is more chance of optimal RPM when needing a boot full of throttle. It makes use of the engines power band better as it keeps the rpms high when you shift up. The only downside is that you will potentially need to shift more, however on many tracks you only use 3-4 gears anyway!
Hope this helps
What does this mean? It means that when cruising at 50mph+, the 6th gear is revving the engine less. In general terms this means less fuel usage and a quieter, less used engine.
The shorter earlier gears allow for quicker acceleration to some degree due to the fact there is more chance of optimal RPM when needing a boot full of throttle. It makes use of the engines power band better as it keeps the rpms high when you shift up. The only downside is that you will potentially need to shift more, however on many tracks you only use 3-4 gears anyway!
Hope this helps
6th gear is something for men only to use :lol:
EdButler said:Bit of a sweeping generalisation here, but in the Z4 specifically gears 2-5 are slightly shorter and the 6th gear is longer than 5th on the 5-speed box.
What does this mean? It means that when cruising at 50mph+, the 6th gear is revving the engine less. In general terms this means less fuel usage and a quieter, less used engine.
The shorter earlier gears allow for quicker acceleration to some degree due to the fact there is more chance of optimal RPM when needing a boot full of throttle. It makes use of the engines power band better as it keeps the rpms high when you shift up. The only downside is that you will potentially need to shift more, however on many tracks you only use 3-4 gears anyway!
Hope this helps
I'm sorry to say mate but that's just flattly incorrect. :|
Both the 5 speed and 6 speed boxes use the same ratios from 1 - 5 on the z4 and all other beemers where the there is a 6 speed option. The only aspect of the drive train that determines the overall ratio is the Differential. 3.0 has a slightly longer final drive (3.07) and therefore cruises at lower revs at motorway speed than the 3.0si and the Z4M, where the latter two have shorter final drives (3.23 Roadster, 3.46 Coupe, 3.62 MCoupe) to aide with acceleration and other sporty gubbins.
The automatics on the other hand have their own set of gearbox ratios (only slightly different) and the shortest final drive (3.64 3.0, 3.74 3.0si), the si's have a longer 5th and 6th gear on the autos, the 6th gear was introduced on the autos at the introduction of the N5* variant engines.
There are also 2 seperate gearbox makes, ZF and getrag than BMW use; however the ratio differences are so minor they're hardly worth mentioning.
So to answer the question, the 6th gear is an overdrive gear that allows for shorter final drives to be fitted to the car for acceleration but maintain a respectable engine RPM at cruising speeds. For all intents and purposes, if you fitted a a 3.0 diff to a 3.0si it'd drive in the exact same manner at the exact same rev points as the 3.0.
Or if you stick a 6 speed box in a car with a 5 speed transmission, again it'd be the same up to the point that you change into 6th gear.
Please note I'm only refering to the 3.0 M54 engine and not the N52 variant; excuse the brain dump I got a little carried away...
th30d0r3 - You are wrong see below, the gear ratios are not the same, 2-5 are like I said. All I got wrong is the FD stating that the 6spd had shorter Final Drive, which I got wrong as when I drove a 2.5i, I swear it was longer geared. I am aware of the difference of FD and 'Gear Ratios', I was just trying to give a simple answer to a simple question. Similarly if someone asked me what time it is, I wouldn't call up the Temps Atomique International and give it them to the nanosecond. :roll:
http://www.bokchoys.com/differential/GearRatios_E46.htm
Anyway im sure the op gets it now, and good luck to them on their new purchase
http://www.bokchoys.com/differential/GearRatios_E46.htm
Anyway im sure the op gets it now, and good luck to them on their new purchase
:th30d0r3 said:EdButler said:Bit of a sweeping generalisation here, but in the Z4 specifically gears 2-5 are slightly shorter and the 6th gear is longer than 5th on the 5-speed box.
What does this mean? It means that when cruising at 50mph+, the 6th gear is revving the engine less. In general terms this means less fuel usage and a quieter, less used engine.
The shorter earlier gears allow for quicker acceleration to some degree due to the fact there is more chance of optimal RPM when needing a boot full of throttle. It makes use of the engines power band better as it keeps the rpms high when you shift up. The only downside is that you will potentially need to shift more, however on many tracks you only use 3-4 gears anyway!
Hope this helps
I'm sorry to say mate but that's just flattly incorrect. :|
Both the 5 speed and 6 speed boxes use the same ratios from 1 - 5 on the z4 and all other beemers where the there is a 6 speed option. The only aspect of the drive train that determines the overall ratio is the Differential. 3.0 has a slightly longer final drive (3.07) and therefore cruises at lower revs at motorway speed than the 3.0si and the Z4M, where the latter two have shorter final drives (3.23 Roadster, 3.46 Coupe, 3.62 MCoupe) to aide with acceleration and other sporty gubbins.
The automatics on the other hand have their own set of gearbox ratios (only slightly different) and the shortest final drive (3.64 3.0, 3.74 3.0si), the si's have a longer 5th and 6th gear on the autos, the 6th gear was introduced on the autos at the introduction of the N5* variant engines.
There are also 2 seperate gearbox makes, ZF and getrag than BMW use; however the ratio differences are so minor they're hardly worth mentioning.
So to answer the question, the 6th gear is an overdrive gear that allows for shorter final drives to be fitted to the car for acceleration but maintain a respectable engine RPM at cruising speeds. For all intents and purposes, if you fitted a a 3.0 diff to a 3.0si it'd drive in the exact same manner at the exact same rev points as the 3.0.
Or if you stick a 6 speed box in a car with a 5 speed transmission, again it'd be the same up to the point that you change into 6th gear.
Please note I'm only refering to the 3.0 M54 engine and not the N52 variant; excuse the brain dump I got a little carried away...
andysat said:
I have 7 gears and man do they shift smooth
Any of you remember the 3-speed column shifter, nicknamed "Three on the Tree" began appearing in America in the late 1930s and became common during the 1940s and '50s.
I think we are just so spoiled
I remember my 1953 Oldsmobiele was like a TANK a tiny window in the rear. The car last oil like mad. I think I had sawdust in that transmission. Anyway drove from Montreal to New York told the Tank Station Attendant (it was a coloured chap) I told him check the gas and fill up the oil, he said "Say what"? I just repeated since I know my gas was good I must have been on my last drop of oil since he added 3 quarts of oil and $2.00 worth of gas. Oh the memory of it all Sorry four is as far as I can go back...Rolf-Dieter said:andysat said:
I have 7 gears and man do they shift smooth
Any of you remember the 3-speed column shifter, nicknamed "Three on the Tree" began appearing in America in the late 1930s and became common during the 1940s and '50s.
I think we are just so spoiled
A
Anonymous
Guest
All the above is smoke and mirrors......... it enables you to rest your hand in a more comfortable position on the gearstick, that was the design remit........
A
Anonymous
Guest
Rolf-Dieter said:) I told him check the gas and fill up the oil, ......... he added 3 quarts of oil and $2.00 worth of gas. Oh the memory of it all
Blimey, they had gas conversions back then when all we could get was petrol..........
