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MG MGF Technical - Steptronic - inferior?

Who else read last weeks Autocar with the feature on the Audi 'Multitronic' CVT 6 speed 'stepped' gearbox? (Page 95 for the techy bit and 29 for the A6 launch, if your interested)

The salient points were, twin multi plate clutches, 6 speed sequential or full auto, 10% better acceleration than a conventional auto and parity with a 5 speed manual (in the A6 bit it actually says faster than a manual!), Fuel consumption parity with the manual, torque handling capacity of 258lb ft, and engine braking when decending hills.

Who else draws the conclusion that MGF Steptronic purchasers will be even further short changed by choosing this version?

Rog
Roger Parker


I still don't understand why the steptronic has been aimed at the 'slower' end of the market.

The technology should make acceleration a dream: always peak power/torque, "I fancy a 6 speed today", etc.
I got the impression from the earliest leaks and rumours that the steptronic was originaly aimed
at the same market as the Audi caters for: sports.

Was it a policy change from Rover to aim it at the city types who want a 'cool' automatic?
Was it because the belts simply snapped too much? After all, I thought that was why CVT didn't take off in the mid 80's.

Interesting if anyone has the inside story on this one...

Paul.
Paul

I think one has to remember that the MGF Steptronic is only being made available on the 1.8i so the loss in 0-60 times is not that great. Also all automatics have always been slower on the 'get up and go' than manual gearboxes and if Audi have produced one that is as good as (or better) than a manual I think this is a breakthrough in modern design. Where the Steptronic scores (so we are told) is on quick gear shifts once moving - I think we must wait and see once the car is generaslly available.

As Paul mentioned early CVT boxes had problems with the drive belts, but I think that was in the DAF days of rubber belts. Again only time will tell and obviously there are some problems why else would the launch be delayed so much. I here it now wont be generally available much befor June 2000.

Ted
Ted Newman

>. I here it now wont be generally available much befor June 2000.

Sorry, should be:- I hear it now wont be generally available much before June 2000.

Ted
Ted Newman

the 0-60 MPH figures for a manual car are only "theorical" : yes, a GOOD driver can reproduce them, but you need to rev the engine high and release the cluch quite brutally, in order to achieve a slight wheelspin and not to drop the RPM.
That's not very healthy for the transmission, and you'll never do it everyday at every stoplight.

But with the Steptronic, all you have to do is pushing the pedal to the metal and the car "jumps". Yes, there's a little sliding in the mechanism, and that's why the 0-60 figures are a little worse than manual "theorical" figures.
In everyday's life, the steptronic is IMO simply faster.

Fabrice
Fabrice


Thought with a CVT box you could press 'go', the revs would rise to 'optimal' level and you would shoot
off with the engine being kept at this rev point. Like the new breed of scooters on the streets.
This, in theory, keeps acceleration times to a minimum.

Don't know if the MG version of the CVT box allows for this 'mode' or simply implements artificial gears.
I do know that the gearing is very long ... and slow.

It may well be fster in day to day life for the 'average' MG owner - whater that is. :-)
Still looks to me that it's a good idea watered down somewhat.

Paul.

Paul

I don't know if anyone else visited the MG stand at the London Motor Show, but I have to say that I was disappointed with the Steptronic. I have yet to drive one, but the central gearstick is so badly placed if you want to select "sports" mode. Also, speaking with the so called salesmen on the stand, they seemed to think it was a total waste of money (good selling point!!!)!!!!
Also, I found the triggers on the steering wheel very difficult to use when attempting a fast corner (ok, I was sitting in the car, making broom broom noises, and swinging the wheel about...but the effect was the same!!!)


IMO, Automatic gear boxes and sports cars just don't mix.
Richard Cook

Big difference in execution between the Audi and MG semi auto boxes. One is a computer controlled manual clutch, with sequential change, whilst the other uses a torque converter and a 'stepped' geared CVT box. It is clear which is going to have the greatest transmission losses- and it isn't the Audi's sequential gear box!

None the less, the CVT in the MG could have over come its inherent weaknesses by having lower and closer gearing. With this, one could imagine rip-roaring acceleration potential from a 1.8i and its better low end torque... and maybe this is where the early rumours of a MG semi auto being faster than a VVC originated from. However, transmission over heating, with associated longevity problems saught to put an end to that dream, and hence the more conservative car we see on the market today. :o(

Not a car I would now aspire to own (although a 'proper' 6 speed semi-auto would still feature on my wish list- sucker for F1 gizmos that I am ;o). There must be a market for this car though- consider it a cut price Mercedes SLK.

Rob
Robert Bell

The base line is that conventional auto gearboxes for the last few years have not suffered the losses that were always inherrant with torque convertor losses. Therefore the current standard auto found in the mid to upper market sector suffers no performance loss, and in some cases (Mercs) have an advantage. This is excluding any 'average' driver inputs.

The Steptronic is yet to be made available and shouts 'F1 style' controls and '6 speed', in other words it is being connected with leading edge technology, yet in reality is is falling well short of this mark. If it was aimed differently then there is some excuse for the deficiencies.

What Audi have now done is place a similar configuration transmission up for comparisons and the Steptronic falls further behind. (Subject to independant testing of course)

Unless there are further revisions being made in answer to these clear deficiencies and lack lustre reception, which is quite possible with the later and later release dates, then I fear that a backlash from potential buyers will hurt manual cars sales and the overall image of all models.

Rog
Roger Parker

Rob,

I've read recently a test of the A6 2.8 "multitronic" (if I remember well its name).
Maybe I don't really understand your previous post, but the new Audi gearbox is clearly a CVT. There are 2 modes : full auto and 6 "stepped" speeds, just as the MG steptronic. Maybe the way the clutch system is achieved is not the same, I just don't know. It's definitively not comparable to an automatised sequential manual gearbox like in the Ferrari F355-F1, F360-F1 or the BMW M3.
BTW,according to the tests, the A6 2.8 multitronic accelerates faster than both the manual and automatic versions (0-100 km/h and 1 kilometer) : contrary to the MGF 1.8i that's slower when steptronic.
The CVT "belt" of the Audi was said to be of a new design : there was a picture and it looked more like a chain. It comes clearly from a different source than the MG CVT, because I met last summer a guy who works for the company (bought by ZF, I believe) that manufactures the Rover CVT gearbox in Belgium and he said the actual version could handle safely not more than 200 N.m of torque. They are developping a bigger unit for engine in the range of 300 N.m (like the 2.8 A6 is), but it won't be released until 2 years.

Fabrice
looking forward to test drive an MGF CVT and make my own opinion !
Fabrice

This thread was discussed between 02/11/1999 and 08/11/1999

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.