Date: Fri, 18 Apr 2003 08:47:59 -0700 From: B&D <NO_SPAMnopsamCOM> Subject: Re: GM to increase SAAB lineup
On 4/18/03 2:35 AM, in article jfcu9vkv3rfapvj5pu9ou9siuk788d8nkenopsamcom, "Martin Rich" <M.G.Richnopsam.ac.uk> wrote: > On Tue, 15 Apr 2003 20:11:56 -0700, B&D <NO_SPAMnopsamCOM> wrote: > > <About continuously variable transmissions> > >> >> Yes! It is an amazing invention - and what I feel the manual transmission >> will go to - and probably most manual transmissions as well. >> >> I had no idea it was Dutch - thanks for the info! > > This is getting way off-topic for Saabs but relevant if you're > interested in CVTs. The first cars made by CVT were made by the Dutch > company DAF in the 1960s (or possibly very late 1950s). DAF was, and > is, primarily a maker of big commercial trucks and city buses but they > started an offshoot making very small and quirky cars. These cars all > had the CVT transmission (and rear wheel drive). > > The ordinary DAFs that you could go out and buy at a dealer weren't > very powerful. Also the combination of a simple automatic and a tiny > car didn't usually appeal to enthusiastic drivers, so DAFs had a > (rather unjustified) reputation for being slow and unexciting. > However they also performed very respectably in rallies. > > DAF sold their car operation to Volvo around 1976 Volvo didn't > develop the CVT, though they fitted it as an option in their 340 > series for years after, and the positioning of the gearbox at the back > of manual Volvo 340s was a legacy of the car being designed to > accommodate the original DAF transmission. > > Of the modern CVTs, the one I'm most familiar with is Nissan's. It's > a very effective way of producing an automatic which works well and > economically with a small engine. I drove a new US Nissan Murano SUV- which has a CVT coupled to a 3.5L V6 that generated about 240lb-ft of torque. It is a bit disconcerting, since there appear to be no shift points. BTW the fuel economy was not too good (less than 20 EPA rating (about 11-12L/100km) in city driving which usually translates to about 16miles per US gallon (14-15L/100km). Ugh. Ended up with a Saab wagon. But the CVT seemed to drive quite well - and seemed to be a reasonably quick responder either in manumatic mode (computer generated shift points) or in full auto. >I don't see it tempting anybody who > wants an 'involving' driving experience away from their manual gearbox > though. Yes, I can see that. But the experience is not about mileage or speed (because CVTs and other modern recently develped automatics such as toyotas "sequential shift" or the new udi one people posted to this group about - get equivalent mileage right now, and do not sap the performance) it is about individual control. I think that in the long run, transmissions will not have manual clutches. As emissions regs continue to tighten, and the public wants better gas mileage, the computers are bound to be more efficient and reliable. On the hybrid cars - the one with the manual shift (Honda Civic) does not have the emissions that the CVT based ones do even at this point - so is not entitled to do things like ride in the carpool lane and will not get as generous a tax rebate from some states as the others. >If you learn to drive on a manual you tend to feel most in > control if the engine and the driven wheels are connected at a fixed > ratio, much as this isn't a particularly efficient way to operate an > internal combustion engine. With the Nissan CVT you are very > conscious of the gear ratio changing; also it feels, if anything, a > bit slower to respond than most conventional automatics. I does *feel* slower, but if you use a stopwatch it is actually a bit quicker (or if you are super skilled at shifting a manual, as very few are, the same). I think the feeling is the tendency of the CVT to "powerboat" upon launch. Nissan did a great job of sound insulation on the Murano, but it does creep in anyway. > Audi and Rover have CVTs which you can hold manually in a fixed ratio. > These should reproduce a bit more of the manual driving experience but > I still don't see these appealing to dedicated manual drivers. Alfa > Romeo's 'Selespeed', which is more like a synchromesh gearbox with > automatic controls, is perhaps more one for really keen drivers who > might be tempted by an automatic I think the "manual driving experience" is going to be more and more for the luddites among us. I think very shortly the new generation of automatic transmissions will exceed in the speed department under all circumstances and will be better at emissions and mileage as compared to people's skill at shifting. There will always be a demand for manual gearboxes for people who want it, but it won't be the preferred option even in Europe. Now having said that, I rue the day that will happen, but I see the writing on the wall.
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