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Posted: 7/31/2009 9:29:43 PM EST
The belt drive ones, the belt runs in variable diameter pulleys.

In Panama City Beach last week we rented a Chinese 150cc scooter that had a CVT and it worked pretty well other than me grabbing the rear brake lever for a clutch lever and having my foot reaching for a non existant rear brake pedal every time I stopped. Scooters use rubber belts that run dry on the variable pulleys, the belts cost about $90 and last 5 to 10K miles.

This got me wondering how the CVT's that Honda and other car manufacturers use hold up and work.

What say you?
Link Posted: 7/31/2009 9:39:20 PM EST
They work good my snow machines and 4 wheelers. They are very efficient and easy to work on.
Link Posted: 7/31/2009 9:41:08 PM EST
They are mostly wasted on cars, the theoretical gearing efficiency is higher, however the parasitic driveline loss is higher as well.

All the cars with a CVT that I'm aware of however have it programmed to go to specific ratios to approximate "gear change lurch" as consumers complained far wide and loud when the initial units came out without it (they thought that they got a one speed and were pissed at the inefficiency).

So really all your doing is buying higher parasitic losses.

Link Posted: 7/31/2009 9:42:05 PM EST
I have a 2006 Ford Five Hundred with a CVT.

I don't really know what to say other than that, in practice, it's exactly like any other automatic transmission. It just shifts differently (basically, gradually and whenever it feels like doing it).

Ford's CVT, and I assume most other car CVTs, is a steel belt. It apparently holds up well, it just needs to get flushed more frequently than other transmissions (every 50k miles IIRC).
Link Posted: 8/1/2009 2:46:37 AM EST
Originally Posted By WhackyPlague:
I have a 2006 Ford Five Hundred with a CVT.

I don't really know what to say other than that, in practice, it's exactly like any other automatic transmission. It just shifts differently (basically, gradually and whenever it feels like doing it).

Ford's CVT, and I assume most other car CVTs, is a steel belt. It apparently holds up well, it just needs to get flushed more frequently than other transmissions (every 50k miles IIRC).


Same car and yr here. Its very smooth you dont feel shifting etc.
Link Posted: 8/1/2009 3:05:30 AM EST
Link Posted: 8/1/2009 3:06:14 AM EST
Originally Posted By MikeSSS:
The belt drive ones, the belt runs in variable diameter pulleys.

In Panama City Beach last week we rented a Chinese 150cc scooter that had a CVT and it worked pretty well other than me grabbing the rear brake lever for a clutch lever and having my foot reaching for a non existant rear brake pedal every time I stopped. Scooters use rubber belts that run dry on the variable pulleys, the belts cost about $90 and last 5 to 10K miles.

This got me wondering how the CVT's that Honda and other car manufacturers use hold up and work.

What say you?



Coming soon...
Link Posted: 8/1/2009 6:32:40 AM EST
CVT is fine for lower/lesser powered vehicles.

Its a different story when real power is available.
Link Posted: 8/1/2009 6:46:32 AM EST
I prefer them in four wheelers, but I've never driven a car with one. A buddy of mine just picked up a new Dodge Caliber, though, so I'll get to test it out.
Link Posted: 8/1/2009 7:05:30 AM EST
There's a new mechanical CVT designed by a company called Nuvinci that uses tilting balls that transmit power via a special fluid that acts as a solid in tight tolerances. They are selling it as a bicycle transmission to generate interest, but the technology is completely scaleable. People seem to like the transmissions on a bicycle-if they weren't efficient, people would be bitching quite a lot as you can feel a few percent here and there on a pedal bike.

It's really neat, there are a handful of Youtube vids. Some guys are mounting small four strokes to them or electric motors for a hybrid bike.
Link Posted: 8/1/2009 6:21:47 PM EST
After posting I Googled "Honda CVT problems forum" and found several posts about Civic CVT transmissions failing around 100K miles and Honda not making good on them. Seems their CVT's aren't as durable as their regular auto transmissions.

They also mention designing some creep into the CVT because people like that for parking and stuff like that.

Link Posted: 8/1/2009 6:29:35 PM EST
I test drove the dodge caliber, and decided against it. Its a very strange experience, and felt like any attempt I made to increase speed via the engine RPMs (gas pedal) was defeated by the transmission simply gearing around me. maybe Im just biased, I much prefer a stick.
Link Posted: 8/1/2009 6:45:28 PM EST
CVT's are not a manual transmission, therefore, are not ideal for cars.

They work great in snowmobiles, ATV's, and small engine stuff though.
Link Posted: 8/1/2009 6:56:08 PM EST

I drove my father-in-law's Jeep Patriot with the CVT for a couple of weeks. It takes a little getting used to, but it is a very nice transmission.

Also test drove a Nissan Versa hatchback with the CVT. It was a very nice small car, and that transmission worked very well with the engine to give the car a lot of pep.

I would not hesitate to get a CVT.
Link Posted: 8/1/2009 7:12:25 PM EST
[Last Edit: 8/1/2009 7:15:15 PM EST by Leisure_Shoot]
We have carried several CVT cars in our rental car fleet over the past few years. Nissan and Dodge/Chrysler in particular.
Customers bring back the Chryslers, complaining "the transmission is slipping" relatively often. (Journey, Caliber, Patriot, Compass, and maybe some Avengers?)
It sounds like a go-cart engine, in the small cars.

While we haven't had any over 50K miles, I can't think of any transmission failures at all. I manage a fairly large fleet of vehicles that are not driven under the most gentle of circumstances, as you may imagine.
Link Posted: 8/1/2009 7:36:08 PM EST
Originally Posted By JBski:
CVT's are not a manual transmission, therefore, are not ideal for cars.

They work great in snowmobiles, ATV's, and small engine stuff though.


I didn't like them in the ATV's I've driven compared to a std ATV . Dad just picked up a new nissan versa SL 1.8L with CVT, so we'll see how it goes, lifetime warranty on the trans so he doesn't have to worry about a replacement at 100k + miles.
Link Posted: 8/1/2009 8:38:49 PM EST
They get better MPG than equivalent cars with auto transmissions, but not as good as a standard.

I'd think that a diesel tuned to work with a CVT would be a very efficient combo.
Link Posted: 8/1/2009 8:59:47 PM EST
[Last Edit: 8/1/2009 9:00:04 PM EST by WhackyPlague]
Originally Posted By Lord_Grey_Boots:
They get better MPG than equivalent cars with auto transmissions, but not as good as a standard.


For a few reasons (not all of them specific to the transmission), current automatic transmissions often get better mileage than the same car with a manual.
Link Posted: 8/1/2009 10:02:08 PM EST

Rented a Jeep Patriot with one. It was a 4 Cyl IIRC, and climbed the hills to Pennsylvania fine all loaded down. That's my only experience with them.
Link Posted: 8/1/2009 10:15:13 PM EST
THis Baja me and 12 other guys made had one (actually a centrifugal clutch and a Baker manual but meh). I've heard pretty bad things about them for "real" cars.

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