Transmissions: Which one works for your driving?
You probably remember not many years ago it was a simple choice between automatic and manual, when it came to cars. Remember that?
It was as easy as deciding to choose gears yourself, or letting the car do it for you - and the majority, including yourself, would’ve probably picked the auto.
But in 2020, there are four kinds of transmission you need to be aware of in order to understand what’s turning the wheels of your next new car.
You might ask the effect of, ‘Why do I need to know? Can’t I just let the car do it and drive?’. Well, yes you can, but there are caveats to simply choosing an automatic today.
There’s the conventional epicyclic automatic we know and understand as the two-pedal type that does all the thinking for you thanks to what’s called a torque converter. But there are two newer transmissions which drive kinda like an auto, look like an auto inside and sound pretty much like the normal automatic you’ve been used to for donkeys’ years.
Except they’re not.
You need to understand your transmissions in order to look after them and make the toniest of tweaks to your driving style in order to avoid abusing them, and therefore get the most out of their brilliant designs.
Here’s how these four transmissions work and how you should choose the right one to suit your driving situation.
Automatic (conventional epicyclic)
This is the one we typically know and love as the set-and-forget transmission type.
It was colloquially knowns at the T-Bar (back when the shifter actually looked like a giant plastic T sticking out of the hump in the floor - think XD Ford Falcon). It’s also known as column-shift in America, where the stalk is commonly mounted to the steering wheel and is pulled forward and down to select forward, neutral, reverse or park.
But keeping it simple, the normal automatic transmission you’re going to buy in Australia is still used today for its resounding benefits in serviceability and robustness.
If you are not especially interested in the task of driving (and that’s not a criticism), and you just want a transmission that allows your to point and squirt, stop and go, then a conventional epicyclic automatic transmission is probably going to suit you fine. But, that’s if you have one - because they’re becoming less popular as the years go by.
They’re known for being somewhat less efficient in sending power from the engine down to the drive shafts and the wheels, primarily because the epicyclic transmission requires increasing revs from the engine to achieve optimum power delivery to the rest of the drivetrain.
See, the transmission’s job is to divert power from the engine to the wheels relative to the speed you’re travelling at. But the ‘old school’ auto which you’re used to hearing as the revs rise with every gear change, means there is a lot of waiting for the revs to be at what’s called “peak power” or the rev-band. In that moment the engine is delivering its maximum amount of power, therefore giving you the ideal amount of acceleration. But only briefly.
Imagine being stopped at a set of lights right now. The car’s idling. Light turns green. You gently accelerate. The revs rise, the engine gets slightly noisier, you go increasingly faster, and continue at your ideal cruising speed. Now, if you do that again with more throttle input, the whole process happens slightly quicker, but you use more fuel as the gears change sooner, because the engine is working harder to reach its peak power to offer you that increased performance.
The conventional automatic spends a lot of time increasing revs trying to reach that optimum peak power point in order to get you going quicker. So there’s a lot of engine work happening with a sub-optimal result in performance, which means fuel consumption is marginally higher than our next two transmissions. And this explains why you need to know about them…
CVT: Continuously Variable Transmission
The CVT is a misunderstood piece of automotive technology. If you had the time, (like, if your kids didn’t exist and you had no job or hobbies), you would read countless motoring reviews about vehicles with CVTs from journalists who spend too much time in performance press vehicles, and many, to this day, will lump criticisms on the CVT without reservation. Almost all of it is unfair and may mislead your purchasing decision.
There are some well-publicised car brands which have had poor early CVT transmission reliability. But there are plenty of brands who’ve got it right. Namely, Subaru - which was forced to tip a lot of R&D into its CVT because the brand’s Boxer engine and symmetrical all-wheel drive system were pivotal to the brand and they needed the fuel economy with solid reliability. Those ill-fated early CVTs are still weighing on brands which got it wrong; Subaru couldn’t afford to make that mistake.
So let’s start with the benefits of CVT.
Essentially, that peak power I discussed with conventional epicyclic automatics, it’s almost always happening in a CVT. There’s no building of revs, no waiting to hit the power band, none of that wasted engine work only to momentarily achieve peak power and lose it again when you change gears.
The CVT is constantly offering you peak power. But don’t think this means cars with CVT are race cars, because CVT transmissions, unlike normal automatics, spend a lot of time making the same engine noise. You’ll see the rev needle sitting constantly on about 3000 to 4000 RPM. And this is where those unfair motoring reviews will say the CVT means a car ‘drones on’ or ‘won’t shut up’ or ‘sounds boring’ or whatever. This is unfair and not really worth your attention; in fact, you should ignore it.
The CVT is brilliant because, to put it very crudely, it’s essentially two pulley wheels with an expending and contracting steel belt between them. As you apply throttle, the pulleys are spun and expand the belt in order to deliver that peak power to the drivetrain. The engine doesn’t have to build and work its way up to the power band, it just goes straight to it because it doesn’t have to deliver power according to the conventional automatic’s fixed gear ratios.
The CVT does still have ratios of expansion of the belt and the drive pulleys, like the normal auto and DCT, but it doesn’t spend large amounts of time locked into those ratios, it just picks the optimum ratio - the most efficient ratio based on what you’re telling the car you need it to do based on your throttle input - and it just makes that happen. You might say the CVT is the ideal transmission in many ways.
Using a CVT, in case you don’t know, is the same as a normal auto. Squeeze the lever button and select P, R, N or D. You can pull the selector toward you to manually select gears, or, often you can use paddle-shifters which have become pretty commonplace. Paddle-shift is as easy as pulling the left paddle (behind the steering wheel) to change down if you’re perhaps approaching a bend on a rural road, or pulling the right paddle to change up as you exit the corner and increase speed. Many new vehicles also come with drive modes which give you pre-determined settings for how aggressively the gears change and how responsive the engine and CVT/transmission is to your throttle inputs.
CVTs are also a very compact transmission. Engineers designing cars don’t need lots of space taken up by rows of gears and servos interconnecting and engaging/disengaging them. I guess you could say with a CVT, shit just happens. And in mechanical or engineering circles there’s an expression: complexity is the enemy of reliability. CVTs are very reliable, they’re robust, they deliver good fuel economy and when you know how to drive them, they’re fairly enjoyable to use, just not if you’re deadset keen on enthusiast-type driving (we’ll get to that).
So how do you drive with a CVT? Well, with a normal auto, you squeeze the throttle and wait for the performance to happen. So it’s delayed; let’s called it reactive - it reacts to what you’re telling it to do.
But for a CVT, it needs to be driven responsively. Instead of giving the vehicle a command and then expecting it to react as soon as you need it to happen, you need to tell the engine (and therefore CVT) what you’re going to need it to do.
What does this mean?
I drive a Subaru Outback with a seven-speed CVT. And I can tell you, driving it like a normal automatic will frustrate you because it feels like you’re giving it an order and it’s taking forever to do as you’ve told it.
But think of it like this: Your dog. It loves you so comprehensively, it will literally obey every single thing you tell it to do. Sit. Stay. Come. Roll over. Bark. Attack?
However, you cannot expect the dog to know your command if you don’t tell it (because dogs can’t read your mind, despite their deep-seated love making them try). A CVT works a bit like this.
You need to leash your ego and think logically about what’s happening in the traffic around you. If you’re flooring it from the lights, you’re not going to achieve much because the CVT and engine need to build up your road speed before offering you significant acceleration. CVTs aren’t instant, but they are consistent. They need historic data from you in order to obey your commands. CVTs are constantly trying to keep you at the optimum revs, but you need to tell the car what those revs need to be; therefore you need to be monitoring the driving situation in order to add or reduce throttle, to apply brakes, to pull a paddle-shift down a ratio to commence overtaking in the next 10 seconds - whatever. You can’t just wait for the situation to be already happening before giving it a command.
So, if you’re a regular city commuter, CVTs are ideal because they give you efficiency and good performance in those environments. But you also need to be sympathetic to that steel belt expending and contracting a squillion times over its life. If you’re that goose who drives hard up to a set of lights and stationary traffic, or you like to creep forward waiting impatiently for the lights to change, or you love big hard throttle inputs when they do change, or even if you are constantly doing the go-stop-go-stop concertina driving (rather than just leaving enough gap to the car in front to coast slowly forward), then you’re going to prematurely wear out that steel drive pulley belt.
This isn’t a design flaw of the CVT, it’s simply an operational characteristic of this technology. CVTs are very hard to abuse, which is what makes them so good; they’re simple, strong, uncomplex - but all machines can be abused and they all have limits. If you prematurely break a CVT belt, that can be very expensive. So you need to 1) Keep it serviced on time, 2) Drive conservatively and 3) Don’t slam the transmission from Reverse into Drive while you’re still moving, because that steel pulley drive belt needs a split second to change direction; be stationary before clunking into D.
Therefore, assess what kind of driving style you fit into. Do you drive aggressively everywhere? Or are you a conservative, patient driver who isn’t trying to set a new lap time down Burke St during peak hour? Can you tweak your driving ever-so-slightly to take advantage of the CVT’s inherent design genius?
If you’re approaching an intersection and the lights change to amber, do you floor it hoping to make it, or do you let off and ease the car to a civilised halt? CVTs are very good at what they do. They’re great on the freeway, where they’re also excellent for using with adaptive cruise control when you need to set your distance marker to the vehicle in front (during peak hour I set mine at 3-4 bars/seconds) and keep a constant, low speed.
Lastly, don’t think this doesn’t mean a CVT cannot to performance driving. It definitely, definitely can. Test drive a WRX. I personally put a WRX through hell during a John Bowe Performance driving course many years ago, sharing Sandown Raceway with big V8 Clubsports and various sports cars, and that CVT was phenomenal. Lap after lap it took upshifts and, more importantly, downshifts (especially into turn 1) like a champion. It was only the standard brakes which couldn’t handle the heat.
Don’t ever let anybody convince you a CVT transmission is shit, because A) CVTs are brilliant, and B) They probably don’t understand how to drive a CVT or, more likely, how to drive. Period.
My Tip: Smile and nod, because you might lose them as friends if you try to school them on CVT awesomeness.
DCT: Dual Clutch Transmission
The DCT is widely considered the new benchmark in performance transmissions. Why? Because they’re fast.
A good DCT will offer you lightning quick gear changes, which is what you want in the modern world of incremental fuel economy improvements and for belting up your favourite twisty backroad.
But you also need the DCT to be durable, because it’s going to go through utter torture driving in congested, stop-start city traffic (as are any other transmission, to be fair). Fortunately, you can have the best of both worlds.
Like the early CVTs, dual-clutch transmissions had a difficult birth due to poor reliability (and subsequent customer support failures) for multiple brands some 10 years or so ago. But today, they’re much improved and brands like Hyundai and Kia have got an eight-speed dual-clutch transmission which has proven very efficient, slick-changing and - importantly - quite durable.
Why is durability so important? Well, not to state the obvious but, there’s a great deal of hard work going on downstairs for a dual-clutch transmission, and they are much more complicated than the super-simple CVT or the venerable epicyclic automatic.
Put simply, there’s actually two small sets of gears (making up the total number for that transmission) and they rely on two clutches to decide which gear is in use. Again, simply, the clutch is a plate that connects the back of the engine to the gearbox. IN a dual-clutch, there are two clutches, obviously, and while you’re using one set of gears, say first gear, the secondary clutch pre-selects second gear, then it’s simply a matter of engaging Clutch 2 when the computer tells it to. While you’re in second gear (clutch 2), third gear is being selected by Clutch 1. When third gear (Clutch 1) is engaged by the computer, Clutch 2 prepares fourth gear. And so on.
However, DCTs have in the past gotten a little confused when it came to anticipating the next gear the driver (and computer) was going to select. Like the CVT, the DCT needs historical data inputs (from you) in order to predict and determine which gear you’re gonna need next. But this can get confusing if you’re changing up and up, but suddenly need to change back down again, because the computer has been predicting you would need higher gears based on your throttle input. Suddenly having to disengage future-fourth gear and get back into preparing second gear has seen these transmissions take a long time to respond and getting confused.
So it’s important to know if you’re interested in a vehicle that has a DCT, and ensure you test drive it accordingly. That doesn’t mean aggressively, because that’s dangerous. But trying to trick it with sudden changes is how to figure out if it’s a well-sorted transmission. You want to tell it you’re accelerating and needing higher gears, then suddenly slow down and require lower gears. This isn’t always easy to do on a test drive from the dealership.
Having said that, generally the DCT is now pretty bloody good. Especially if you love driving and pulling paddle-shifters up and down a twisty mountain road.
What you should definitely not do in a DCT is creep in slow or stationary traffic. Either stop, or get going. Otherwise you’re going to prematurely wear out your clutch.
Looks like a regular auto - definitely isn’t.
The DCT looks like a normal auto, much like the CVT, but it definitely is not an conventional epicyclic automatic. So don’t drive it like this. Be responsible with what information your right foot is telling the computer and what gears the clutches need to be preselected to. Again, these are brilliant automotive technologies, but they can be punished if you don’t treat them with mechanical sympathy. I mean, you’re welcome to, but you’ll pay for it. DCTs are not cheap to replace and clutch packs are expensive, especially in a DCT because this transmission does not have a torque converter like the normal auto, so the clutch will slip if you creep along at the lights or doing constant low-speed manoeuvring.
Decide what you’re doing, what speed you need to do and get the task done. Don’t dither about up steep driveways or inch closer to the stationary car in front. Just sit still.
When parking, try to be as efficient as possible. Get your angle right on approach to the parking space. Don’t have 400 stabs at squeezing between two ill-parked Range Rovers.
And if you do frequent, moderately heavy towing, that’s okay, just don’t spend 10 minutes trying to reverse it up the driveway.
Apart from these few conditions, DCTs are so breathtakingly sweet to use in their element - that mountain road or that blistering overtake (without being an idiot, of course). DCTs change gear quicker than conventional epicyclic automatics, and you still get to bask in the adrenaline rush of building revs, cracking the peak power band, and then instantly swapping gears.
Done well, the dual-clutch transmission is, in many respects, even better than doing it yourself.
Manual: DIY gear shift
You never forget your first. First best friend, first dog, first love, first time. First car.
Your kids will probably never understand, but there was once a time where we used to have three pedals divided by two feet, and two hands each doing a task of its own.
The mechanical conducting of your first car’s row boat symphony is something you’ll never forget, Alzeimers’s pending of course. Actually, if you loved driving manual as much as I did growing up and learning to drive, then you’ll probably forget everything else should you be hit by such an ruthless and wicked disease, except the feeling of changing gear in an old car.
Mine was a Torana.
Fortunately, in many respects the manual gearbox has all but disappeared for good reason. It’s slow, it’s laborious, it’s inefficient, and for many it was a barricade to getting their license and learning to drive. Some people struggle with the cognitive juggling act that is driving a manual car in real-world traffic.
So today, there are very few new cars you’ll find, especially in the family car categories, which offer a manual transmission.
There’s the Hyundai i30 N and Fastback N, which are especially great to drive and change gears yourself in, as well as fellow sports cars like the Subaru WRX, pint-sized Mazda MX-5, Toyota BRZ and Subaru 86 (yes, that’s a joke), the BMW Z4, the Kia Picanto GT. You can get some single-cab and dual-cab utes still with a manual gearbox in the base models, and you can have a brand new 4x4 LandCruiser with a floor-mounted tractor lever.
There are a few family cars offering a manual such as the Mitsubishi ASX and Toyota RAV4, Kia Cerato, Toyota Corolla, Mazda 3, Hyundai Venue, Kia Sportage, Suzuki Swift and so forth. But you have to look and typically specify manual if that’s what you really want.
Unfortunately, you’ll notice some changes with the manual today from the one you remember all those years ago. They’re much harder to find, obviously, and they are usually very slick. Meaning they’re actually very efficient, smooth and typically have very short bite points on the clutch and (apart from the LandCruiser, designed alongside the steam locomotive, I think) with very short throws for the gear stick.
If you’re a carmaker and you’re having to keep making a gearbox that’s sold in about 5 per cent of your total vehicle sales, you don’t want to overdo it on materials and the most efficient manual gearbox integration has minimal materials used in manufacturing each unit. So they’re small, light, simple and efficient now.
This might spoilt the romance and nostalgia of those big dramatic gearchanges you remember (I certainly do) back when social media was writing letters or talking on the phone, or when bullying at school was dealt with in either of two ways: you fight the bully or you tolerate the bully - none of this cowardice online bullying where the perpetrator doesn’t even have the balls to show their name or face. (Getting off topic here).
So yes, if you can find a manual new car today, you’re actually, perversely, probably going to enjoy the experience.
Driving a Mazda MX-5 for example is absolutely thrilling, just like flying down the laneways as a kid on your bike, despite being relatively slow, felt utterly exhilarating. Changing gears in an MX-5 is rapid, cogent, repetitive, demanding of your attention, but it works, it’s efficient and it’s enjoyable when you get it right. You are in control.
The rumbling of a Subaru WRX’s punchy Boxer flat-four in front of your left foot is going to be heart-pounding and engaging like no CVT could ever be, providing you put in the hard work.
This is the flip-side of the manual gearbox’s coin. You are forced to commit to driving that transmission as the car demands it. If you get lazy, you’ll grind a gear or ride the clutch. If you can’t be bothered, you won’t go anywhere. If you’re not paying attention, you’ll stall, be in the wrong gear or both. And if you’re stupid enough to be on your phone when the light goes green, you’ll embarrass yourself trying to get going again as the traffic beeps you from behind.
But, when you do put in the effort, when you give your attention, when you’re focused and undistracted, when you get it right and can go forwards, backwards, parking slow or giving a bootfull en route to your favourite spot, and when you pull in, pump that clutch pedal and give the lever that neutral wriggle and turn everything off, you can get out satisfied.
There’s nothing logical or efficient or rational about choosing a manual transmission in 2020 and beyond. Except when it only makes perfect sense.
If you have any questions about which transmission will suit your driving situations, or you need help choosing your next new car, email me by clicking the red box below.