When does a CVT become conveniently useful?

Once a novelty in the slushbox segment, continuously variable transmissions (CVT) are getting increasingly popular.

This is because of the multiple forward ratios that the transmission presents to the driver, instead of a set number of gears. 

In the Philippines, this particular tranny saw national attention when it was part of the original equipment for the mid-2000s Honda City subcompact sedan and Honda Jazz subcompact hatchback.

The tranny was deemed a good alternative to a market that still preferred stick shifts, given that one just used the right foot to transition between the gas and brake pedals.

However, the Honda CVTs of the abovementioned era had issues, usually throttle response lag and a nasty shudder when moving from Neutral to Drive.

Allegedly, the remedy was to change the transmission fluid to a better one recommended by the manufacturer. But the problem persisted for many City/Jazz owners during that time.

Since then, a bevy of manufacturers has brought out their own takes on the CVT.

These include Nissan’s XTronic (on the Murano and X-Trail crossovers), Chevrolet’s VT40 Hydramatic (for the Spark subcompact) and Toyota’s Aisin-sourced unit (for the Vios subcompact sedan, along with the Raize and Veloz).

That said, the fact that a number of automakers install the tranny means that they believe in what it can do and how it can benefit the Filipino motorist.

But what exactly does the CVT do? How is it better than a stick shift and your typical slushbox?

When shifting gears isn’t set in steel

As mentioned in its name, a CVT does its "upshifting and downshifting" via a near-perpetual range of gear ratios.

While a traditional automatic transmission uses a wide variety of intricate parts to shift between a range of preset gears, most CVT systems work through a pulley system. 

This system consists of a driving shaft and a driven shaft, with a pulley splined unto each shaft. Each pulley has two conical sheaves that face each other, with a pushbelt shoehorned between said sheaves.

That pushbelt is made out of specially pressed steel, strung together between rings of high alloy steel for added flexibility and durability, so that transmitting engine torque and horsepower to the wheels won’t be a problem. 

The cones can move to increase or decrease the belt diameter to change gear ratios. This allows for quick shifting into the needed ratio for increased power, along with better fuel economy.

Though there are no gears in a CVT, some units mimic a more traditional changing of gears by moving to preset points. These are done via a gearstick or paddle shifters on the steering wheel.

Happy days with unlimited gears

Automakers are realizing that the CVT is great for their mass-market brands, particularly those with naturally aspirated powerplants toting narrow powerbands and small displacements.

The nigh-infinite choices of forward ratios help bridge the gap between gears, thus improving acceleration and even fuel consumption. 

Also, the effort to go up inclines is reduced. This is because your average automatic gearbox with fixed gears has to work harder to find the right forward ratio, versus a CVT that almost always finds the perfect ratio to smoothly provide torque and horsepower without hard shifting. 

Also, the wide range of gears means that the transmission doesn’t experience shift shock during downshifting.

After the good – the bad and the ugly 

The cones and pulleys that comprise the bulk of CVT components are more expensive than the parts on a conventional automatic.

As such, repair and replacement of the aforementioned parts (or even the entire CVT outright) are costlier. That's why it is never found on performance vehicles.

Installing a CVT on, say, a Honda Civic Type R or a Ford Mustang might jack up the price to the realm of ₱5 million for the Civic or past ₱6 million for the Ford. 

A third downside to a CVT is the noise it generates, usually from the bearings holding the cones and pulleys together or the use of improper fluid.

This is because there’s a lot of torque/horsepower loss due to friction between pushbelt and pulleys. And with that friction comes noise from the pulley and cone bearings. 

Is a CVT the way to go?

Yes and no.

No, because of the potential added cost of ownership and the noise pollution from prolonged usage of a CVT-equipped vehicle.

Yes, because the use of a CVT makes a four-wheeler better its performance from rest, along with increasing its potential for fuel parsimony. 

That said, should one get a vehicle with a CVT, one should be acutely aware of potential slipping, added noise generation, jerky behavior from the tranny, engine speed fluctuation and delays in transition between gears. 

Hence, it’s important that you have money stashed away that can be used in case the CVT needs repairs. Don’t forget, though, that a CVT, like an automobile in general, breaks down if warning signs are neglected.

But if you stick faithfully to maintenance schedules, listen carefully to the sounds an engine and CVT make (and do the necessary adjustments), using a vehicle with a CVT should be a pleasurable experience.

What do you think of CVTs?