Today: CV Transmissions

Dear Car Talk

Dear Car Talk | Jul 02, 2013

Dear Tom and Ray:

I'm considering getting a new Honda Accord four-cylinder. For 2013, Honda went to a CV transmission, replacing the five-speed automatic. I wonder about (1) the longevity of this type of transmission; (2) the effect on fuel economy; and (3) the overall driving experience for someone (me) who has driven both manuals and automatics for 50 years. Your carefully considered opinion is appreciated.

-- Pete

TOM: Hm. Would you settle for one of our usual opinions, which are ill-considered and half-baked?

RAY: I think it's fine for you to get the CVT, Pete. We're living in a period of rapid gear inflation. For a long time, we had three-speed transmissions. Then came four-, five- and, pretty quickly, six-speed automatics. Then, in just the past couple of years, we started seeing seven- and eight-speeds, and now we hear about companies working on nine- and 10-speed gearboxes.

TOM: The reason to add gears is that, generally speaking, the more gears you have, the better your fuel economy. The more you can match the demands of your driving to the most efficient gear ratio for those demands, the less fuel you waste.

RAY: A CVT (continuously variable transmission) is a gearbox with infinitely variable ratios. Actually, no gears at all -- just belts that move constantly up and down two cone-shaped pulley-thingies to adjust the gear ratios.

TOM: It's definitely a plus for fuel economy. That's why Honda has started using it.

RAY: In terms of longevity, we don't really know. Some of the early CVTs had trouble with high-torque engines. But Nissan and other companies have been using them successfully for years now, and, so far, there don't seem to be any particular problems.

TOM: The driving experience is a little different. Under most normal, gentle driving conditions, you probably won't even notice it. Good transmissions are so smooth these days that you barely feel the shifts now anyway. But when you really need to accelerate, you will see a difference in the way the transmission and engine interact with each other.

RAY: If you stomp on the gas, like when you're on a highway on-ramp, you'll notice that the engine revs way up at first, to give you immediate power. And then, as the car picks up speed, the engine actually goes slower and slower as the transmission continues to adjust the gear ratios as the car needs less power.

TOM: It's a little odd at first, but so was trying to work with my brother, and I got used to it.

RAY: It's certainly not a reason to avoid the car, Pete. And while there's no guarantee, Honda, overall, has a pretty good track record for durability and reliability.

TOM: I'd suggest that you go and test-drive one. You'll see what we're talking about. Make sure you include some sort of sudden, harder acceleration in your test drive so you can experience the primary difference we're talking about.

RAY: But remember, every new technology is a little weird at first. When the first automatic transmissions came out, it was weird not to shift the gears yourself. When the first anti-lock brakes came out, it was weird not to pump the pedal in a panic stop. And when the first iPhone came out, it was weird to be able to have such a cool phone and still not hear what the other person was saying.

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