As we see more and more hybrid and plug-in-hybrid vehicles enter the auto market it also appears that the continuously variable transmission (CVT) is also becoming increasingly prevalent. In this article, I’m going to look at what CVT transmissions are, how they work, how they compare to other automatic transmissions and whether CVT transmissions are good for towing.
CVT transmissions are not the best option for towing because they can’t cope with as much torque from the engine as traditional automatic or even manual transmissions can. The one thing a vehicle needs to be good for towing is plenty of torque, and the more torque a vehicle can produce the better it tends to be at towing. Vehicles equipped with CVT transmissions have lower maximum towing capacities than vehicles with traditional manual or automatic transmissions.
What is a CVT transmission?
The CVT, or continuously variable transmission to give it the full name, is a type of automatic transmission that uses two pulleys with a steel belt running between them instead of the collection of cogs a traditional automatic transmission uses. To continuously vary the gear ratios, a CVT simultaneously adjusts the diameter of both the “drive pulley” and the “driven pulley.”
The drive pulley distributes the torque from the engine and the driven pulley works to transfer that torque to the wheels of the vehicle. The idea behind a CVT is to deliver stepless shifting between different gear ratios and avoid the clunky and less-efficient shifting of a traditional transmission as the different cogs are engaged.
Effectively, a CVT has an infinite number of available gear ratios that are altered continuously to help deliver a very smooth driving experience. Regular automatic and manual transmissions have a fixed number of gear ratios while CVT’s aren’t torque-dependent because they make use of those infinite gear ratios to send the available power to the wheels.
Why do Japanese automakers favour CVT transmissions?
If you’ve been looking to buy a new vehicle over the last few years you’ll probably have noticed that it’s Japanese automakers that tend to favour the CVT. In fact, until hybrid and plug-in hybrid vehicles started to become more widely available in recent times you’d probably have struggled to find a CVT transmission in anything other than a Japanese vehicle.
Japanese manufacturers have long favoured CVT technology because the driving conditions in Japan are more suited to CVTs than other types of transmission. Driving in Japan means negotiating tight, winding roads and congested city streets and CVTs are smoother and more fuel-efficient than traditional automatic and manual transmissions.
Outright performance and big towing capability are not required for the majority of driving in Japan, and this is why Japanese automakers have become such experts in CVT technology over many years.
This could lead you to assume that a CVT is superior to any other type of transmission that relies on a fixed number of available gears. After all, everyone can see that as the years go by automatic transmissions are offering more and more gears. GM and Ford have many vehicles available now with 10-speed automatic transmissions and Mercedes and BMW have long favoured 7, 8 and 9-speed autos.
More is usually better, isn’t it? Therefore, surely a transmission with an infinite number of gear ratios is going to be better than one that only has 10 or less? Well, not necessarily.
What is a CVT like to drive?
If CVTs were “better” to drive than other transmissions then you’d have seen them in Formula One years ago. In fact, if they offered any sort of performance advantage over other types of transmission then F1 would probably have invented them in the first place.
CVT transmissions are smooth to drive and they are often the most fuel-efficient option where fuel economy is a big deal, such as with hybrid and plug-in hybrid vehicles. Unfortunately, they can also noisy, especially when coupled with low-powered engines as they tend to stay at high RPM and cause the engine to rev excessively under hard acceleration.
Another feature of driving a CVT is you won’t feel it when it shifts gears because it doesn’t actually shift gear at all because it doesn’t have any gears to start with. However, manufacturers have now caught on to this last issue and some CVTs now simulate gear changes. How convincing this feels will be up to the individual, but there’s no doubt that CVT technology is getting infinitely better than it used to be.
Can you tow with a CVT?
There’s no problem whatsoever when it comes to towing a trailer with a vehicle equipped with a CVT transmission as long as you don’t exceed the vehicle’s maximum towing capacity or maximum allowable weight when passengers and cargo are taken into account.
However, there’s a big difference between “can you tow with a CVT?” and “is a CVT good for towing?” Before I go into the pros and cons of towing with a CVT you only have to ask yourself one question, which is how many pickup trucks on sale in America are available with a CVT transmission?
To give you an idea of the difference a CVT can make to the towing capability of a vehicle we only have to look at something like the 2021 Toyota Highlander. When equipped with the standard 3.5-liter V-6 gas engine and eight-speed automatic transmission, the Highlander is rated to tow up to a maximum of 5,000 pounds. When equipped with the CVT instead, the Highlander Hybrid only has a maximum tow rating of 3,500 pounds.
Now you could say this is because the Highlander Hybrid has a hybrid gas/electric powertrain based around an inline-four with an output that’s 52 horsepower less than the V-6 version, and there’s some merit in that argument. However, this then has to make you ask why do hybrid and plugin-hybrid vehicles use CVTs almost exclusively much of the time?
Are CVT transmissions good for towing then?
Even though you may find a vehicle with a CVT transmission that’s rated to tow more weight than you need to tow there’s more to towing than just whether the vehicle is rated to tow that weight or not. For example, you may find yourself towing on different surfaces and how a transmission engages and how it applies the torque to the wheels can make a huge difference.
Let’s say you are towing a boat on a trailer that weighs-in at 2,950 pounds and you have an SUV that’s rated to tow up to 3,500 pounds. On dry pavement, you’ll probably be fine with any transmission, but what if you’re vehicle and trailer are on mud, gravel or wet grass?
A lot of the time there’s a delay with a CVT when you apply the accelerator before the power is applied to the wheels, and that’s not a help when it comes to towing. When towing in challenging circumstances you want as much torque as you can possibly muster so the power is applied as immediately as possible.
To be fair to the technology and the manufacturers that champion it, modern CVTs are massively better than they used to be in every application, although they can still take some getting used to. What I would say here, though, is that if you are serious about towing with a vehicle at the moment there are better transmissions for the job than a CVT.
Why do hybrids always seem to use CVT transmissions?
Hybrid and plug-in-hybrid vehicles tend to prefer CVT transmissions because those types of vehicles are designed primarily to be more fuel-efficient than gas-only models, and CVT transmissions help to maximize the fuel-efficiency of hybrid powertrains. A CVT is also lighter than a traditional transmission with all those heavy metal cogs inside and reducing vehicle weight is another way to improve fuel-efficiency.
Are CVT transmissions reliable?
Although it is getting better as the technology develops over time, CVT transmissions don’t have the best reputation for reliability. Even though CVTs are cheaper to produce and lighter than a traditional manual or automatic transmission they’re usually more expensive to repair than other types of transmission.
Don’t get me wrong; nobody wants to have to pay for a transmission repair of any sort as they usually come with a hefty price ticket. Unfortunately, there’s very little that puts more strain on a transmission than towing a trailer, especially when close to or at the vehicle’s maximum tow rating. It, therefore, stands to reason that if you’re going to be towing a lot a CVT isn’t going to be the best choice by any measure.
Which vehicles offer CVT transmissions?
You’ll find lots of CVT-equipped vehicles in the ranges of Honda, Lexus, Mitsubishi, Nissan, Infiniti, Subaru and Toyota. The South Korean Kia and Hyundai brands also have CVT versions of their Accent, Elantra, Venue, Forte, Rio, Seltos and Soul models. American brands are getting in the act too now with Buick, Chevy, Chrysler, Ford and Lincoln offering hybrid and plug-in-hybrid models now equipped with CVTs.
Should you buy a CVT to tow with?
If you only occasionally tow a relatively lightweight trailer then you shouldn’t be put off buying a hybrid or plug-in hybrid vehicle with a CVT transmission as long as the maximum towing capacity is more than the weight of your fully-loaded trailer. On the other hand, if you’re regularly going to be towing 3,000 pounds or more, especially up and down steep gradients or on less-than-ideal surfaces, I’d stay away from a CVT.
I’d say this advice would be relevant for at least a few years yet until the technology gets better, or until fully-electric vehicles replace everything else and transmissions are then no longer an issue.