When consumers fork over a big pile of their hard-earned cash for a new car, it should be a given that the power train is robust, durable and reliable. Consumers should feel confident that this model year is at least as good as the previous model year.
But alas, this is not always the case. Around the year 2000, the continuously variable transmission, or CVT, was introduced into the marketplace and started to become common around 2010. The CVT uses two pulleys with adjustable diameters connected by a steel chain belt instead of gears. The halves of each pulley move to and away from each other, changing the effective diameter of the pulleys. The steel chain is multiple links wide similar to a watch band. There is no sprocket with teeth. There are electronic CVT systems in hybrid cars that do not use the pulley-belt system, which tend to operate just fine.
By varying the pulley diameters, the car speed is varied while allowing the engine to operate at a constant efficient speed. This is a wonderful idea in theory, but in reality, there is a lot of friction and slipping and sliding between the belt and the pulleys generating metal particles. A traditional automatic transmission uses gears that are positive engagement, which means no slipping).
Belts and pulleys are fine for use with auxiliary equipment such as water pumps, alternators, air conditioners and power steering, but are not great for high-power, high-torque automatic transmissions.
The pulley-belt system is fundamentally flawed — there is no way to prevent the sliding, slipping and particle generation. One manufacturer almost went bankrupt because of its use of CVTs, while another manufacturer has no CVT cars. Yes, over the years, they have been improved by using better materials and software, but like an athlete with a ball and chain around his ankle, he will never outrun the guy without those impediments, no matter how much he improves his physical condition. Essentially, the CVT is near the limit of its capability, and to squeeze more out is just diminishing returns. The CVT will still require more maintenance — more frequent fluid and filter changes, around $300 to $500 for each service. If servicing is neglected, then a new transmission is likely to cost upward of $5,000.
I will not mention any manufacturer names in order to protect the guilty, but they are easy to identify using Google.
One manufacturer even uses CVT on their expensive luxury car models and makes “step shift” programming available to simulate traditional gear changes.
Really? A side benefit of CVT is supposed to be smooth shifting. I wonder how these owners will feel when they realize that their expensive luxury car has a cheap transmission. Sometimes, beauty is only skin deep.
CVT will never be as good as a gear-type automatic transmission and is a major step backward for the car industry. CVTs are third-rate and do not belong in any vehicle ever.
Even the late Bob Weber, a writer known as Motormouth whose columns on cars appeared in the Tribune, said in a September column before his passing that “I am not yet sold on the reliability of continuously variable transmissions. They are getting better, and many carmakers claim that their cars will easily go over 100,000 miles with proper care. Conventional automatic transmissions have a proven track record with many going over 200,000 miles.” I think Weber was being too kind to the CVT. Maybe in the 1970s, 100,000 miles on a transmission was good, but today, it’s nothing to get excited about. Modern gear-type transmissions should be good for the 200,000 miles or more, even with minimal maintenance.
Personally, I would not own a CVT car. If you are car shopping, new or used, be careful what you are buying. If you buy a used CVT car, do not overpay, check out the maintenance history, and factor in regular fluid and filter replacement costs.
A few new cars have very attractive pricing. For example, one model has an suggested retail price of $19,200 for a CVT and $17,400 for a five-speed manual transmission. I would only consider the five-speed manual.
Why are manufacturers using CVTs? The main reason is federally mandated fuel mileage requirements. CVT will improve car mileage by about 5% due to efficient constant engine speed. The CVT also has less moving parts, making it cheaper to manufacture — a big benefit to the car companies — as long as there are not excessive failures during the warranty period.
Maintenance, repair or replacement expenses gets passed on to the consumer.
The fallout includes damaged reputations, irate customers and lost confidence and early final resting places at junk yards.
After 10 or 15 years, these CVT cars may become worthless boat anchors, while their gear transmission cousins are still in the prime of life. I predict CVT owners will be really irate. What goes around comes around.
Ed Sokalski lives in Allentown, Pennsylvania, and is a retired mechanical engineer.
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