Tuesday 6th February 2007

Eight-speed gearboxes arrive

BMW, Merc and Lexus indulge in ratio wars

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BMW 7-Series to get 8-speed box

The war to add more gear ratios is on.

BMW looks set to introduce an eight-speed automatic ZF gearbox into the 7-Series in 2009, according to automotive analysts, CSM Worldwide. The aim is to help it compete with the similarly-equipped Lexus LS460 and IS-F sports saloon.

And it was only three years or so ago that seven-speed auto boxes made their debut in a Mercedes, with a six-speed making it into the 7-Series in 2001.

According to one report, GM is ready to follow the trend with systems due in Cadillacs and maybe Buicks.

The question has to be asked though: are all these gears warranted, given the added weight and complexity they will entail? Do these engines have so narrow a power band that eight speeds are strictly necessary -- or is it all just marketing?

[sprinter885]

Unnecessary garbage if you ask me. Stick with the good ol' porridge stirrer manual gears (5 maximum) & let the ECU sort out where power/torque is required. My (early)S Type auto has fun sorting it's 5 gears out never mind another 2 or 3!!
Just who are these multi-gear boxes supposed to benefit??

[peanutjb]

sprinter885 said:

Unnecessary garbage if you ask me. Stick with the good ol' porridge stirrer manual gears (5 maximum) & let the ECU sort out where power/torque is required. My (early)S Type auto has fun sorting it's 5 gears out never mind another 2 or 3!!
Just who are these multi-gear boxes supposed to benefit??

6 speeds have their uses
7 speeds seems a tad excessive
8 speeds is just plain silly

[_____]

sprinter885 said:

Unnecessary garbage if you ask me. Stick with the good ol' porridge stirrer manual gears (5 maximum) & let the ECU sort out where power/torque is required. My (early)S Type auto has fun sorting it's 5 gears out never mind another 2 or 3!!
Just who are these multi-gear boxes supposed to benefit??

5 speeds you fancy git! A two speed powerglide is all you need

might as well have a CVT otherwise

[potatoboy666]

Wasn't there a Mercedes or a mercedes concept car with 2 reverse gears?

[oxladed]

Surely this is all marketing garb. Much like razors - 1 blade wasn't enough. 2 did the job much better until that wasn't enough. Then 3... Now we're up to 5 blades. Where will it all end? We'll all be waking up in the morning shaving with 300 blades and getting into our 38 cogged motors. Stop already!

Dave

[sprinter885]

potatoboy666 said:

Wasn't there a Mercedes or a mercedes concept car with 2 reverse gears?

"Special" one engineered by JCB- could do 13.6 mph in high ratio reverse.

[r5gttgaz]

Why not have a 4 speed with 2 final ratios? 50cc GP bikes used to employ this tactic when needing 16 speeds to keep them in the powerband.

[jont999]

I could understand this if the cars were high-revving, narrow-powerband machines, but these makes usually have at least 300bhp and torque to match.

[jp7152]

Good thing though is it helps with fuel economy at faster cruising speeds and also makes the car quieter.

[dazren]

jp7152 said:

Good thing though is it helps with fuel economy at faster cruising speeds and also makes the car quieter.

If gear 8 is the same ratio as top gear on a 6 speed box there would be no difference.

Edited by dazren on Tuesday 6th February 13:34

[E38]

Surely the point of a big car with a big engine is that the power/torque band is so huge is doesn't matter what gear you are in. I wouldn't want to have constant gear changes when accelerating up to motorway speed, I have a diesel for that.

[Maxmpg]

dazren said:

jp7152 said:

Good thing though is it helps with fuel economy at faster cruising speeds and also makes the car quieter.

If gear 8 is the same ratio as top gear on a 6 speed box there would be no difference.

...and for the whole life of the car you'd be carrying the weight penalty of the extra 1, 2 or 3 gears.

[festernath]

potatoboy666 said:

Wasn't there a Mercedes or a mercedes concept car with 2 reverse gears?

All Merc autos have 2 reverse gears. This isn't hype - the 'box chooses to use the higher of the two gears when winter mode is selected. Try reversing a rear wheel drive auto on snow if you're not convinced...

[qube_TA]

super tall cruising gears are great for MPG, does seem a little odd dividing the transmission into 8 ratios though especially as auto boxes usually have less gears than their manual counterparts.

My mountain bike has 18 gears so these cars still have a long way to go :P

Matthew

[angrys3owner]

qube_TA said:

My mountain bike has 18 gears so these cars still have a long way to go :P

Any reason why you've not got 27?

Edited by angrys3owner on Tuesday 6th February 14:39

[scoobiewrx]

I have 27 gears on my MB....and i need then with my legs

Surely any more than 6 gears on probably 99% of cars is plenty. I like a 5 spd box, and 6 is good, specially in a decent oil burner or performance car, but 7/8 spd is just novelty value and does nothing but as has been said....add a sheload of weight to the car.

Plus with all the traffic we have to put up with today you would be continuosly changing gear all the time and not enjoy the driving so much. What a polava!!

..What gear am i in?... Which gear do i need to be in now??...
Bugger that!!

[chim666]

jp7152 said:

Good thing though is it helps with fuel economy at faster cruising speeds and also makes the car quieter.

....like overdrive used to do on my old 'MGB'?

[DangerM0use]

6 speed in both the M3 and RX8 suit the cars well. 7 or 8 gears would not.

[ianhoward]

Triumph TR's had effectively 7 gears way back in the late 1950's and 1960's fitted to the TR3, 4, 4A, 5 and the early 6's - Overdrive in 2nd, 3rd and 4th.

So not much has changed then! :-)

[Zod]

The Americans' six speed manual M5 is slower than the seven speed SMG M3; slower acceleration through the gears.