Mechanical CVT Transmissions

Yes, CVTs in some newer cars (Honda Hybrid, Subaru Outback, ...) have a wear out mechanism, but so do all modern automatic transmissions. If they are designed correctly for the vehicle weight/engine power, they should last more than 150k miles, but some are under designed and have a history of shorter life:

• Ford EAT - My 1990 Ford Probe had a three speed auto tranny that failed at 118k miles. When I stopped by the dealer for a rebuild estimate, He sai "You got 188k miles out of that transmission?" (It lasted that long due to its small 4 cylinder engine)
  These trannys had an average life that was barely longer than their 50k mile warranty in Ford's larger cars/6 cylinder engines.
• Honda Civic Hybrid - Their CVTs have a history of early failures that can be forestalled by periodic ATF refreshes.

I tend to keep my cars a long time and would prefer to not have to replace a tranny. Even in my 2004 Prius (205k miles so far), I do periodic ATF drain/refills (at least every 60k miles, but I suggest one early one at 30k miles) to keep the metallic load low in the ATF and protect the MG windings.

JeffD

 

Indeed the HSD is a really elegant and neat design that basically does away with a transmission - no clutch, no bands, and no cones. Its reliability is well documented and its smooth as silk. A major Plus for the Prius.

 

It's easy to find stories of things going bad on the internet, but the fact is CVTs have been around for years, and if they were really that bad, no one would buy them. They are generally more efficient than a standard slush box, and I suspect they easier to implement selectable driving modes(econ, sport, etc.) on.

I'm just disappointed when the manufacturer gives them virtual gears so they lack like a regular transmission.

 

There are people that don't like the sound of maximum power. When accelerating, CVT keep the ICE at RPM that provides maximum power. I like the sound of maximum power and like it to remain there until I back off the accelerator.

Those people like the sound of ICE revving up and down to think it is doing some work. They actually think that's natural because they are used to it. I can understand why they like it but I can't stand them for not realizing they have been conditioned to like it.

 

Agreed... and what REALLY gets my goat is that some of these same people say that acceleration with a CVT gives them a "slipping clutch" feel. Especially ridiculous when referring to the HSD, which has no mechanical clutches to slip.

 

Agreed. I think there are a lot of folks out there who still don't appreciate the uniqueness of this power-train.

 

Honda also had some problems with standard auto behind their V6 in the early 2000's. Mistakes and issues can crop up in any component. It doesn't necessarily mean every one of that component type are bad.

 

One problem of perception with the Prius is that at full power it sounds like it's being abused. It should have a small amount of intake noise or exhaust note that make it sound like an engine instead of an asmatic senior citizen getting a tread-mill stress test. That wouldn't make it's excellent powertrain any better, but it wouldn't sound so funny.

 

Nissan has the greatest market share in north america of CVT as far as I know. Exempting some issues in their original Muranos that had these, they are reliable transmissions, proven now by the fact at least a million of them are in the road, from the Murano to the Altima, Maxima, probably others.

It does have among the lamest sounds ever when under full throttle.

 

Atkinson cycle does sound different. Rev limit is 5,200 rpm so there is no abuse there. You are right, it is the perception of non-hybrid drivers that are not aware of the differences.

 

I can't speak w/authority on their Nissan's CVT reliability but do recall hearing about some problems. As such, they ended up extending warranties on them to 10 year/120K miles (NissanAssist.com) on a bunch of '03 to '10 CVT vehicles, including the NAH even though the NAH's CVT is basically the power split device and nothing like the others.

Nissan I believe gets most/all of their CVTs (except for the NAH) from JATCO Ltd ||| Belt CVT |||.

 

Interesting you should mention that. I had an 07 HCH and the transmission went bad in about 6 months. It actually made the car pretty interesting to drive, as sometimes you'd get regen, sometimes not, othertimes it revved high. I think I drove it for a day or two before I could take it in to get fixed. On a side note, I also had to have both front window regulators replaced, too. I traded that car in on the Prius, and couldn't be happier about it.

 

PSD and CVT two very different things.... with PSD you have electric motor giving you some power right away...so to me, there is night and day difference.

people need to try real CVT and see why I think those virtual gears are very important

 

Its not training, or a problem of perception, the engine note is not pleasing. I simply think Toyota did not spend time or money on this. It also isn't a matter of being trained to like that which sounds bad Given a different engine note an eCVT can sound good, but the software needs to apply virtual gears that "slip" into the next virtual gear. That would give the best of both worlds, other than the additional cost and weight for the hybrid components.

+1

 

I think of it as a baritone sewing machine, that helps! <G>

 

I would skip the fake fixed gear ratios but it should sound like an engine instead of some wheezy abused device/person.

I don't think my wife's Acua engine is any louder than a Prius at full throttle, but at least what you hear sounds like an engine.

This should sound different
Injen Air Intakes for Toyota - Injen Short Ram Intake 2010 Toyota Prius 1.8 Hybrid
I wouldn't go that far on a Prius but would like to hear what it sounds like.

 

Hey, I just turn the stereo up.
The reason for virtual gearing is to get rid of some of the steady state drone at less than full throttle. The engine does have a wide efficiency band. An idea would have power mode choose a higher engine rpm, so that when the throttle is pushed battery power could add. In eco, probably exactly what we have now. With normal going to some narrow virtual gears.