DCT......TCT? - badbusdriver

Just read the headline of an article in April edition of Car magazine. It seems that before long there will be a new breed of transmission, possibly with 3 clutches and as many as 11 gears!. You would think sorting the 'issues' with dual clutch transmissions would be more important than making them even more complex?

Oh dear

Cue rolling of eyes!

DCT......TCT? - gordonbennet

Oh no, you can just hear the pub bores already.

I have no doubt they will be wonderful whilst new and working, wouldn't want to be the poor blighter who owns one out of warranty that's kaput, thankfully the chances of that being the case are less than zero.

DCT......TCT? - SLO76
Totally unnecessary. Overcomplex and guaranteed to go expensively wrong later in the vehicles life especially when gearbox oil changes are almost always ignored by customers and the non-franchise workshops they often service these complex cars with to save money which is more often than not a total false economy.

It's all in the name of reducing emissions and improving economy but at what cost? No car needs 11 gears and three clutches. Imagine the cost of replacing something like this. I had a customer who bought an early low mileage Audi TT V6 DSG many years ago when it was 3yrs old if memory serves. I advised him not to scrimp on maintenance and that a dealer history was advisable and desirable for resale but he took it to a well known fast fit chain for servicing every year instead then ended up with a bill for the guts of £6,000 for a replacement box at less than 70,000 miles when it catastrophically failed, most likely due to the neglected box oil change which was due at 40k.

As these complex automated manuals age dealers are more and more wary of them and value them accordingly, factoring in the risk and the cost of a warranty with the necessary claims limit to cope with a failure. While traditional torque converter boxes were generally as robust as any manual in the past.
DCT......TCT? - gordonbennet

That £6k bill would buy an awful lot of extra fuel and the extra VED incurred by the small savings over a torque converter box.

People neglecting their cars costs them untold money and misery, will they listen to a bit of common sense and hard earned experience, will they heck.

DCT......TCT? - Engineer Andy

Just read the headline of an article in April edition of Car magazine. It seems that before long there will be a new breed of transmission, possibly with 3 clutches and as many as 11 gears!. You would think sorting the 'issues' with dual clutch transmissions would be more important than making them even more complex?

Oh dear

Cue rolling of eyes!

Maybe these designers used to work for razor blade firms, with their endless quest to have the most number of blades on the razor. Why do I get the impression this is something eminating from Germany? You'd thought by now they'd learned their lesson with the DSG fiasco. Obviously not.

DCT......TCT? - Terry W

Two thoughts - mostly concerning futility of the increased complexity:

- 11 gears makes it theoretically less useful than a CVT transmission - but no more effective in real life. Perhaps the brainpower should have been devoted to optimising CVT transmissions

- most engine designers pursue a useful spread of torque across a wide rev range. Somewhat pointless with either CVT or 6+ gear renges.

I have wondered whether I would really notice if my 6 speed manual Octavia gearbox was reduced to a slightly more widely spread five. The costs of 11 speeds and 3 clutches must substantially outweigh any operating cost benefits.

DCT......TCT? - badbusdriver

You would think it was the Germans, but no, after reading the rest of the article i can confirm the idea comes from across the pond.

Darrell L Robinette, assistant professor at the Michigan Technological University is the brains behind this 11 speed triple clutch (+ 2 reverse gears!) developed jointly with GM.Seems like they envisage that different types of drivers will use different gears depending on their driving style etc, rather than the box using all the gears all of the time. Still, seems incredibly complex, and given the aim is to keep the engine in the 'sweet spot' as much as possible, something the (much more reliable) CVT gearbox has already been doing for many many years. Granted, some people really dont seem to like them, but surely the boffins could make them work more like people seem to want them.

Interesting to read about mentalist Swedish supercar maker Koenigsegg's Regara, in which, by comparison, they have gone to the complete opposite end of the scale by doing away with the gearbox (as we know it) completely!. The 5.0 turbo V8 uses direct drive at a ratio of 2.85:1 (for those who understand such things, not like me!) along with 3 electric motors to fill in the gaps and deal with menial things such as reversing and driving at sub warp-speed!. A top speed of 249mph can be reached from a standing start in 'less than 20 seconds' and apparently it will go from 93-155mph in 3.2 seconds.

Anyway, my wife will be taking delivery of her CVT jazz in a few weeks, so we will see how that goes. The last car i was in with a CVT gearbox was my Dads DAF 55 way back in the very early 80's!

DCT......TCT? - RT

Electric transmission is one way forward - infinitely high torque at zero speed and absolutely stepless in operation - so the engine, diesel, petrol, LPG, CNG, hydrogen, gas turbine can be fully optimised for a single rpm and not need to spread thec rpm as at present.

 

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