1. CVTs generate ridiculous levels of irrational hatred amongst "car guys."
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2. Subaru extended their CVT warranty, as far as I can tell, to help allay this rising tide of irrationality, not because there were actual issues beyond statistical norms. All transmissions of all types and from all manufacturers will exhibit occasional problems.
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3. As YoGeorge points out, the best available source of statistical data for automotive reliability -- Consumer Reports -- has shown Foresters to exhibit very good to excellent transmission reliability in the years since the CVT was introduced.
I'm an engineer of many decades, with degrees from Usyd, VUW, Harvard & served as a Harvard Consultant to The White House, and I've owed Foresters for over twenty years.
Re the three paras cited above, let me say:
Re #1: I completely disagree that fears about CVTs are "irrational hatred". There are much higher failure rates in CVTs than in the prior automatic gearbox.
Re #2: Subaru USA extended warranty because of known real problems, not to "help allay this rising tide of irrationality".
Re #3: At time of reclark's writing, CVT had not been widely sold by Subaru for sufficient years to show up in reliability ratings.
For starters, a CVT has between 10x and 40x as much metal-to-metal micro-abrasion surface area as the four speed automatic gearbox that preceded CVT. The CVT chain is like heavier-duty bicycle chains, set-up six-across (bonded) to handle the torque. Just like a bicycle, steel teeth protrude up into those chains, on each expandable spindle. By comparison, the prior auto gearbox had just two sets (at any given time) of solid gears properly meshed, so just a few bands of 1-3mm-wide strips across teeth, where metal-to-metal meet. Motorcycle and bicycle chains work, because they are regularly oiled, and are not 'encased' in a gearbox, to recirculate the metal filings. The circulating metal filings are a killer for the bearings that are lubricated by that same gearbox oil. In my case, my 2015 Forester (MY15 2.5-litre CVT) has been driven gently but now has a noticeable whine from the front-diff portion of the CVT, at 128,000km - so under 100k miles but not covered by warranty. The metal filings given off by chain more acutely wear the bearings in the front diff (and elsewhere), rather than causing failure of the chain itself. So, in this way, there is a misdirection at play - the wear happens on the chain, but it is the bearings that fail. But the proof is the amount of metal in the gearbox oil! By comparison, my earlier 2001 Forester (MY01 2-litre Auto gearbox) still had nil transmission issues at 400,000km when I retired the vehicle to a farm, with the normal head gasket problem of overheating as water is gradually sucked into combustion chamber. But at this point, facing an A$6000 (US$4000) quote to rebuild gearbox, I'm seriously considering bringing the earlier Forester back into action, as the far more reliable vehicle.
Re the design basics of a CVT chain design, let me note:
A. No high-torque vehicles (eg heavy trucks) use a CVT, preferring fixed gears for reliability.
B. You will recall, Subaru never sought to get customers to request CVT, but instead, all of a sudden, customers found that the 'automatic' version of each model was in fact a 'forced switch' to CVT.
C. All the metal filings given off by the chain need to be promptly removed from the gearbox oil, by simply design changes, using a good filter or by super-magnet affixed to inside of gearbox filler cap.
Re Subaru's actions ought to have been:
D. Supply CVT transmission ONLY if asked by customer;
E. Don't buy a CVT if you life in a mountainous location;
F: Never tow using a CVT;
G: Change the gearbox oil every 20,000km;
H: Provide untimed warranty out to 120k miles for all.
So, the USP (unique selling point) for Subaru was RELIABLE AWD with HIGH RESALE values. With all the CVT not reliable or re-saleable after 100k miles, due to gearbox problems that are expensive to repair, Subaru has violated its own historic formula of making only small incremental changes, to not disrupt the reliability that won it a wide customer base. For over 20 years, I was a strong supporter of Forester, for providing reliable AWD and good value. Now the depreciation cost is up to 50cents/km based on its shorter expected life, and I would no longer recommend anyone to buy a Forester.
