OK, so I'm rather rudely going to hijack your post, sorry.
I'm contemplating test driving an 08 159 1.9 JTDm with the QTronic gearbox.
Qtronic, wise purchase or old selespeed???
That could be read two ways! I don't know whether you mean:
(1) QTronic - should I get it or should I get a Selespeed?
(2) QTronic - is it good, or is it like an older version of a Selespeed?
(1) Selespeed is only available on the 2.2JTS petrol 159s, Breras, and Spiders, and it tends to be on the Ti versions, or some other RHD versions sold in Australia, Japan or Singapore. I don't think they were sold in the UK, but perhaps you get "grey imports". The Selespeed of this generation has a lot more programmed behaviour (two operating modes plus learning capability) when compared to the 156/147 Selespeed.
When I drove a Selespeed Brera and a Selespeed 159, I found they rode the clutch a lot in normal mode, to give the feeling of a regular automatic. Unfortunately its control of the throttle during this clutch-slipping makes the engine feel generally unresponsive. In Sport mode, the responsiveness is greater, but the difficulty of driving smoothly (familiar to 156 Selespeed drivers) returns. The system seems to have a mind of its own more often than FIAT's Dualogic of recent times.
The QTronic is available with 1.9 diesel, 2.4 diesel, and 3.2 V6 petrol engines. It is a six-speed automatic that, in my opinion, is well-matched to the diesel engine characteristics. You get engine braking when required, and it keeps the engine revs correct despite the fairly narrow rev range of the diesel compared to the petrol. There didn't seem any need to use the Tiptronic mode to override the automatic's choices. There also seemed to be very little slip in the torque converter compared to other Japanese autos.
In contrast, I didn't think the QTronic was particularly well-matched to the 3.2 V6 engine - it seemed much less confident and would easily kick down two ratios and immediately go back up one. It seemed to get caught out easily, even though the engine had a much wider usable rev range, which was bizarre. I get the impression more time should have been spent on mapping the shift points, but I guess that owners will adapt to using the Tiptronic override.
(2) QTronic is a conventional torque converter transmission (slush box) made by Aisin Warner of Japan (owned by Toyota). I suppose you could say it is old-fashioned engineering compared to a Selespeed (or other automated manual gearbox), but it includes many refinements made to the traditional auto design for performance and light weight. Apart from having six ratios, it has nothing in common with the Selespeed. The QTronic still has a mechanically-driven fluid pump, valve body, clutches, bands, variable hydraulic pressure, etc. which Selespeed does not have.
When compared to the manual version, the QTronic worsens the fuel economy by 10%, adds about a second to the 0-60 acceleration time, and also reduces the top speed slightly. (Selespeed, being a manual gearbox at its core, has the same performance and economy as the manual-transmission version).
Aisin six-speed FWD gearboxes are short-lived in several other vehicle models (Volvo in particular) and require replacements of sticking solenoids and adjustments of clutches and brake bands, often within 30,000 miles. Do a Google search for 'Volvo XC70 transmission problems'. Or 'Volvo transmission class action lawsuit' - many cases were brought to trial. Recent Selespeed versions seem comparatively reliable and certainly don't require stripping down to make skilled adjustments, though to be fair, there are a lot more Aisin auto boxes out there. Particularly in Toyotas, and they're not known for dropping like flies. Maybe Toyota is covering it up through their excellent service network and recall campaigns.
However, I found a fair number of 2006-2011 Mazda 6 owners reporting total failures of their Aisin 6-speed automatics, but the problems here were mostly blamed on the wrong fluid being put in. It needs a special 'type 3309' ATF.
Strangely, in the Alfa 159, the QTronic is very reliable and problem-free. Many people come on a forum such as this one to complain about other problems, but the only QTronic problem reported here was a selector problem inside the car. No-one seems to be getting solenoids replaced or bands adjusted. It's curious, but it may have something to do with the manual transmission of 1.9JTDm 159s being prone to bearing failures. There's also the lifespan of clutch and DMF to consider, which makes the QTronic, relatively, a lot more reliable. At least, I thought so - I'm picking mine up tomorrow.