2009 Legacy to feature CVT transmission

See the following article.

http://news.en.autos.sympatico.msn.ca/article.aspx?cp-documentid=5318637

Subaru to Launch CVTs on New Vehicles

2009 Legacy to Feature CVT

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Canadian Auto Press

The gearless CVT transmission comes and goes in waves of popularity. Previously isolated to European and Japanese-market city cars, they've become an aide in the modern quest for fuel-efficient vehicles around the world. Without physical ratios or a torque converter, they’re more efficient than their regular automatic transmission counterparts, but are prone to what's called the rubber band effect where the engine's speed rises disproportionately to the speed of the car.

New technology has helped to reduce the negative sides of the CVT, and has allowed it to be used in more powerful applications. One brand that's capitalized on this is Nissan, which offers CVTs in practically every model it makes, but for its heavy-duty SUVs, trucks and the 350Z sports car. Because of the CVT's efficiency, all Toyota and Lexus hybrid models use the technology, as does the Honda Civic Hybrid and the Nissan Altima Hybrid. Prestige brands have also worked with CVT gearboxes. Audi's MultiTronic CVT transmission utilizes a metal link chain for front-wheel drive A4s, while Mercedes-Benz's A- and B-Class feature a CVT with seven artificially created ratios instead of a conventional automatic.

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On the contrary, there are some brands that haven't been particularly pleased with the results of their CVT transmissions. Ford dropped their ZF-built CVT from the Five Hundred full-size sedan and Freestyle crossover when they made the jump to the Taurus update. Saturn completely discarded CVTs after offering them on the ION and the outgoing VUE. The previous MINI Cooper featured a CVT transmission in place of an automatic, though it's no longer available.

Now Subaru, one of the quirkiest automakers around, known for their all-wheel drive systems, unique boxer engines and durability, is getting ready to trod down the CVT path once again, according to Winding Road magazine. Having been one of the first to offer a CVT in North America, with its subcompact Justy, it is already a believer in the technologies' many advantages. The new gearbox would be used in place of a standard automatic, and will be available with most of the mainstream engines that the brand offers. Subaru also hopes to have a CVT available in every car it makes by the year 2010.

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Due to the power limitations that CVTs have, we doubt that they'd be featured on the turbocharged 2.5-litre H-4 engine that will move the ultra-powerful Impreza WRX STi, but current CVT technology would still enable it to be used on the less powerful Impreza WRX, Legacy and Forester models. The first Subaru product to feature a CVT transmission is projected to be the 2009 Legacy that is also set for a facelift in that particular model year.

Subaru's first diesel, a 2.0-litre horizontally opposed engine (a world first for this engine configuration) will be available in North America within the next few years, but the brand hopes on making another world first by mating this new CVT to it. The combination of a high-efficiency diesel engine with a CVT should help make the forthcoming Legacy one of the thriftiest midsize sedans on the market.

^Its is an auto tranny.

It just feels a little different with no drop in rpm and hesitation while changing gears.

My father had a Nissan Murano w CVT for 3 years and I have driven it, including for days at at time. The CVT has a tendency to keep the engine in the same rpm range. When cruising at a set speed, the engine rpm is always varying a little as the belt keeps re-adjusting, so it sound like a constant drone.

CVT might have a theorical advantage for fuel economy, but it feels too much like one is driving a snowmobile.

Well there goes the hope of 5EAts for the N/A...

But CVTs are a necessary step in upping Subaru's fleet mpg.

or a golf cart... no driving enthusiast would want this...

Even if it's quicker 0-60?

Even if it's quicker 0-60?

I'd be OK with a CVT if someone could pull it off. The problem is just that I don't think anyone has done a proper ECU and TCU mating and made an engine that knows how to work with one. Every CVT I've been in (both of them) the engine tends to 'run away' from the transmission when they stepped on it, and ended up with really poor performance from it.

I'm not sure how you tune an engine to make a CVT work. I'm guessing you need to somehow get torque and HP to both peak at the same RPM, so that the CVT can hold there under acceleration? Seems like quite a challenge, even for the theoretical efficiency gains.

Jon[in CT] post 2009 Legacy/Outback model codes and colours on NASIOC, I only see 4eat/5eat/5mt/6mt.

Unless Subaru is going to make CVT available only in Canada like the 07+ wagons.

CVTs are a good things. I don't think I would want one in the GT (but then I wouldnt want an auto at all) but in N/A is should be a great improvement over the 4EAT.

CVTs work so much better, I believe that people dislike them simply because its not a conventional gear shift, it fluxuates.

Nissan uses rubber-band-drive (CVT) in their cars.. even the 350Z auto has it.. it makes the car feel ridiculously slow and powerless all the time.

I am not looking forward to this.

a lot of people who are more gearheads than I claim it wont be a bad thing so long as it can be tuned to NOT SUCK but we'll see.. chances are this is going to grow a few seconds onto the 0-60 time and save fuel economy at the sake of performance.

Even if it's quicker 0-60?

Yes...it is simply an awful driving experience.

CVTs are theoretically superior to conventional transmissions in that they are able to keep an engine at the RPM which provides maximum horsepower (during hard acceleration) or maximum efficiency (during highway cruising).

Some people dislike them because they are accustomed to riding the power band from let's say 2000 rpm up to 5000 rpm. However, by definition there is only one RPM that provides maximum power, and someone driving a car with a conventional transmission (standard or automatic) is only at that point for a split second before moving back down the curve. So, assuming there are no major mechanical inefficiencies associated with the architecture of a CVT, it SHOULD always provide superior acceleration and fuel economy to either an auto or manual tranny.

I have a CVT in my Prius (it's actually not a true CVT, but works in much the same way) and find it quite enjoyable that I can instantly summon the peak horsepower at any time and at any speed merely by flooring it (of course, I might be one of the few Prius drivers who floors it regularly). Then, when cruising, the engine rpms drop to an inaudible level (even at 75 mph). Conversely, in my Outback XT, at 75mph my tach is reading north of 3000rpm and I definitely hear it. (Don't get me wrong, I love my Outback XT). Yes, it takes a little getting used to, but that's true of many new technologies.

The reason hybrids almost universally have CVTs is that they can maximize power or efficiency at any speed. This is necessary when your main goal is to maximize MPG and therefore minimize engine displacement. Also, hybrid buyers as a rule don't mind spending extra money up front for technology that will be more efficient down the road.

The point is, CVTs are great if the automaker invests enough in testing and development. If an automaker tries to build one on the cheap or pairs it with the wrong engine, it should be avoided. But the same could be said for almost all things automotive or otherwise.

In summary, I'm an enthusiast who would never purchase a car with a conventional automatic transmission. I loved my Mustang GT before I traded it in for my Prius. Now I still have the Prius, and I also have an OBXT, both of which I love, for different reasons. CVTs aren't bad, they're just different.

I'd be OK with a CVT if someone could pull it off. The problem is just that I don't think anyone has done a proper ECU and TCU mating and made an engine that knows how to work with one. Every CVT I've been in (both of them) the engine tends to 'run away' from the transmission when they stepped on it, and ended up with really poor performance from it.

 

I'm not sure how you tune an engine to make a CVT work. I'm guessing you need to somehow get torque and HP to both peak at the same RPM, so that the CVT can hold there under acceleration? Seems like quite a challenge, even for the theoretical efficiency gains.

You do not need torque and HP to peak at the same RPM. HP is the only thing that matters, provided the transmission is able to keep the engine spinning at a high enough RPM. The only reason low RPM torque is even useful in an engine is because it gives greater flexibility in terms of less shifting of the transmission (ie larger power band). However, in a CVT, this is irrelevant, since infinite shifting is possible (and not noticeable by the driver), and a large power band is not needed.

FYI, HP is a function of torque and RPM (HP=torque*RPM/5250). This means that if an engine makes 200 lb-ft at 5250 rpm the hp will also be 200. However, it takes 400 lb-ft to make 200 hp at 2612.5, since the cylinders are only firing half as often.

In short, if you have a lot of gears and don't mind shifting (both of these statements are infinitely true for CVTs), power is the only thing that matters.