Wondering how to rev match? This is your ultimate guide! If you don’t know what rev-matching is, don’t worry, we’ll delve deeper into what it is, how to rev match, and whether or not you actually need to do it.
What Is Rev-Matching?
Rev-matching is simply the act of raising the engine speed (the RPM) to match the speed of the lower gear (transmission speed) when you shift down. This way, the rev will match the speed of the lower gear, hence why they call it rev-matching. Some people may refer to it as “throttle blipping”.
Also, some people may refer to it as “heel and toe”. But heel and toe is a specific method of rev-matching, which we will also discuss on how to do it.
Keep in mind that only cars with a manual transmission can rev-match. This is because raising the RPM – also known as blipping the throttle – requires you to do it while the clutch is disengaged (when you press the clutch pedal). Since automatic transmissions don’t have a clutch pedal, you can’t rev match in one.
Is It The Same As Double Clutching?
No, that’s an entirely different technique. The purpose of double-clutching is to match the engine’s input shaft to the transmission output shaft. If the speeds don’t match, the gear won’t engage. This method is used in older cars without a synchromesh in the transmission.
Modern cars now all have a synchromesh, which matches the shaft speeds for you. So, there’s no need for you to do this if you drive a modern car. However, commercial trucks and specialty vehicles still often require the driver to double clutch. This is because they don’t have a synchromesh, which is susceptible to breakdowns in heavy vehicles.
Why Should I Rev Match?
So, that’s what rev-matching is, but why do you need to do it? If you drive a stickshift, you may notice that when you shift down the car will bog down and lurch forward. Specifically, when you lift your foot off the clutch to engage it once again. This is because the engine speed wasn’t matching the speed of the lower gear.
Lower gears are larger in diameter, which brings the RPM higher since the engine needs to work harder to spin it. As mentioned, rev-matching brings the engine speed higher. This results in the engine already matching the speed, leading to a smoother downshift.
As an example, let’s say you were at 3,500rpm in fourth gear. As you press the clutch and shift down to third gear, the RPM will drop completely. Then as you release the clutch pedal, the RPM will climb back up to the lower gear’s speed, let’s say at 4,500rpm as an example. At this point, the transmission will bog down and the car will lurch forward making the change feel rough.
With rev-matching, you “blip” the throttle to bring the engine to 4,500rpm, which is the lower gear’s speed. So, once you release the clutch, the engine will already be doing the gear’s speed and the transmission won’t bog down. This video from Engineering Explained will probably better explain how it all works:
To summarize, here are the benefits of rev-matching:
- Smoother downshifts, making the commute feel more comfortable for everyone in the car.
- Reduces stress on the drivetrain, especially the drive shaft.
- Help to produce better lap times during track days or in a race (more on this later).
Is Rev-Matching Necessary?
We’ll get this out of the way: no. Rev-matching will help reduce stress on your transmission and driveline, but there are other – possibly more effective – ways to maintain your transmission. Additionally, rev-matching requires quite a bit of practice. Believe me, even after eight years of driving I still struggle to do it.
If you’re not used to it, rev-matching requires quite a lot of focus and attention – attention that’s better used for paying attention to your surroundings when you’re on a public road.
For this reason, it’s better to practice on a race track or a secluded place. Don’t force yourself to do it unless it already feels natural to you. It’s a bit like left-foot braking; fine if you’re used to it, but if not, you’ll find yourself applying too much force which can be dangerous as someone may rear-end you.
Moreover, some cars are more difficult to rev match, especially if you use the heel and toe method. This is because in some cars the brake pedal sits a bit further away from the throttle. Since you normally rev-match while you brake, reaching both pedals can be difficult in some cars.
It’s normally easier in cars with a throttle pedal that’s planted to the floor and sits close to the brake pedal. Bottom line, no need to do it if you’re not used to it. But if you’re used to it, then, by all means, rev-match when you downshift.
Are There Downsides To Rev Matching?
Rev-matching sounds good, right? It makes driving smoother and helps to reduce stress on your powertrain. But are there any downsides? Not a lot, the main downside of rev-matching is that you’re likely to use more fuel.
There’s no research on how much more fuel you will use by rev-matching, so we can’t tell you an exact figure. However, you will definitely use more fuel since when you tap the throttle during rev-matching, the car will inject fuel into the cylinders to bring the RPM up. That being said, it’s believed that the fuel usage is minimal.
The other downside isn’t a downside per se, but more of a risk. If you over-rev during rev-matching, this can damage the clutch and transmission. For example, let’s say you’re supposed to rev the engine to 4,500rpm. But you accidentally tap the throttle too hard and the RPM climbs to 5,500rpm instead. When you lift off the clutch, this can damage your transmission.
While damage will likely be minimal and won’t immediately destroy your transmission, it will still cause unnecessary strain and wear. The effects are similar to dumping the clutch immediately during a standing start. While not immediately dangerous, be wary of this risk if you want to learn how to rev match.
How To Rev Match: Step By Step Guide
There are two methods on how to rev match. The first method is simply using your right foot to tap the throttle as you shift down. There isn’t any name for this as people simply refer to it as rev-matching, so for this article, we’ll call it the “Standard” method.
Meanwhile, the other method is called “heel and toe”, which is the method you use when you downshift and brake the car simultaneously.
Before we begin, we’d like to remind you it’s a good idea to find a safe space to do this. It’s not quite as dangerous as, say, doing burnouts. But doing something you’re not used to on public roads with other drivers around you isn’t a great idea either. An empty stretch of road or parking would be good. But track driving programs are probably the ideal way to learn to do this – although it’s not free.
Health and safety out of the way, here’s how to rev match:
How To Rev Match: The “Standard” Method
This first method will simply require you to tap the throttle. If you’re simply slowing down without braking, this is the method to use and it’s quite a lot easier than the heel and toe method. You can also use this method if you’ve already brake, and now you’re downshifting before entering a corner or coming to a complete stop.
In any case, here’s how to do it:
- If you’re approaching a corner, brake and slow down to a speed that would be safe to turn into the corner.
- Afterward, press the clutch and engage the lower gear. For example, from third to second gear, or whichever gear is appropriate for the speed you’re going.
- Once the gear is in, use your right foot to tap the throttle and bring the RPM up.
- After the engine reaches an appropriate RPM, release the clutch pedal.
- If done correctly, the change will be smooth and the car won’t lurch forward.
- Repeat steps 2 – 4 if you’re changing down multiple times.
Of course, it will be difficult to know where the RPM will exactly be at. But as long it’s close enough, the downshift will feel much smoother. After a bit of practice, you’ll know where the RPM will exactly be when you change down, and you’ll instinctively know just how hard to tap the throttle.
How To Rev Match: The Heel And Toe Method
As mentioned, the heel and toe method is used when you’re simultaneously braking and downshifting the gears. This is the method used by many racing drivers as it’s more efficient and helps to improve lap times.
This method is unnecessary for road use, but it’s a rite of passage for any car enthusiast that loves driving above all else:
- As you approach a corner, press the brake pedal with your right foot.
- While braking, press the clutch pedal down and shift down to the appropriate gear.
- Before lifting off the clutch pedal, tap the throttle by using the heel of your right foot. As mentioned, this is why it’s called the heel and toe method: your toe presses the brake, and the heel presses the throttle. If the pedals are close enough – or you have large feet – you may be able to blip the throttle by using the side of your foot.
- Once the engine reaches the appropriate RPM, release the clutch pedal.
- Repeat steps 2 – 4 if you’re changing down multiple times. Remember that this should all be done ideally before you start entering the corner.
- If done correctly, the car will feel smooth during the downshift and you’ve successfully done the heel and toe method.
Just like the “standard” method, heel and toe will take a bit of practice until you can instinctively do it. Again, you don’t need to do this when you’re driving on public roads. But it will help you to go faster and shave a few seconds off your lap time when you’re on the track. Speaking of which…
How To Rev Match: How It Helps You Go Faster
So, how exactly does rev-matching helps you to go faster? These are the reasons why rev-matching helps you to go faster while driving on a track:
1. Faster Acceleration
First, it will help the car to accelerate faster. When you downshift without rev-matching, the engine will require time to catch up with the higher RPM of the lower gear. The time required is often milliseconds, but this can add up, and every second counts when you’re driving on a track as fast as possible.
With rev-matching, the engine won’t have to catch up with the RPM – or at least, it won’t require as much time. Instead, you’re immediately in the power band and can accelerate much faster out of a corner.
2. It Helps To Keep The Car In Balance
The second way it helps is with the car’s balance. As mentioned, the car will lurch or jolt forward when you downshift without rev-matching. When the car jolts forward, this transfers weight and force to the front of the car. This sudden transfer of weight can upset the car’s balance, possibly causing it to lose traction.
When this happens, the car may either understeer as it’s now front-heavy. Or the rear-end may break traction, causing the rear tires to let go. This will upset the rear-end balance and cause the car to oversteer. If either of these happens, the driver will need to correct the car, likely losing speed in the process thus slowing the lap time.
By using rev-matching, the shift will be smoother hence keeping the car in balance. With the balance in check, the car will have traction which again helps with cornering speed and acceleration out of the corner. This is why racing drivers rev-match (if the car has a manual transmission) as every racing discipline requires complete control of the car. Take a look at how Nick Galante does it:
3. It Prevents The Wheels From Locking Up
This only happens in extreme cases. Specifically, when you shift down to a gear too low for the speed you’re going, it will lock up the driven wheels. For example, let’s say the maximum top speed of 2nd gear is 50mph. However, at the time of shifting down to 2nd, you’re going 70mph.
Once you let go of the clutch, the engine will overrev. Your clutch will have to work hard trying to match the speeds, and this will cause the wheels to lock up as the engine’s RPM is too high.
Needless to say, wheel lockups are not something you want to be happening. Wheel lockups will increase stopping distances, meaning you may go in too deep into a corner. This results in slower speeds through the corner, and possibly slower acceleration out of it as well. And of course, wheel lockups can upset the car’s balance.
4. Reduces Stress On The Drivetrain
Last but not least, rev-matching helps to reduce stress on the drivetrain. While racing cars have their components serviced or even replaced every few races (or sometimes even in-between every race), they will still need to last the entire race. This has nothing to do with going faster, but it does help to ensure that the car’s drivetrain can last the entire race.
After all, what’s the point of being faster than everyone else if the car breaks down before you reach the chequered flag? As ex-McLaren F1 team boss Ron Dennis says: “To finish first, first you have to finish.”
Automatic Rev Matching
Want to rev match without actually learning how to rev match? Don’t worry, there’s no shame in that. Some carmakers program automatic rev-matching into some of their cars as a means to help the driver get more performance out of the car without the hassle.
Automatic rev-matching is basically software that’s been programmed into the car. When the driver downshifts and lifts off the clutch, the ECU will automatically blip the throttle and bring the engine speed up. Negating the need for the driver to blip the throttle pedal. Here are some cars that have automatic rev-matching:
- Nissan 370Z
- Hyundai i30 N
- MINI Cooper S
- Ford Mustang GT (standard in 2019 model onwards)
- Porsche 911 (991 generation onwards), and Porsche 718 Boxster/Cayman. Both have auto rev-matching if equipped with the manual transmission and optional Sport Chrono Package
More cars come with auto rev-match, and we can’t possibly list them all. But those are some of the cars, and many more sports cars with a manual transmission come with auto rev-match nowadays. Check their website if you’re curious that a sports car you’re planning to buy has an auto rev-match feature.
There’s a lot of argument going on about rev-matching. Some like it because it helps to reduce strain on the drivetrain automatically. While others hate it because it takes the fun out of driving and sometimes there’s no option to turn it off. For example, you can’t turn it off in the MINI Cooper without turning off the Dynamic Stability Control system entirely.
Is It The Same As “Rev-Hang”?
This is an entirely different thing to rev-matching. Rev-hang is when the engine’s RPM stays elevated when you press the clutch, rather than dropping to the idle RPM as it should.
Then when you lift off the clutch, the RPM will suddenly drop to catch up (or down), causing a jolt and making driving feel rougher. It’s kind of like the opposite of what happens when you downshift without rev-matching.
This problem is present mostly in modern cars, and it has to do with the electronic throttle body and ECU programming in modern cars. The throttle body is what controls the fuel and airflow into your engine. When you press the gas pedal, the throttle body opens to allow fuel to enter the engine, giving you the desired power.
Modern cars use electronic throttle bodies because they’re more linear and can give better throttle feel than mechanical ones. However, many carmakers program the ECU to prevent the RPM from dropping down immediately to produce better emissions.
In a nutshell, after you lift off the throttle, there’s still some fuel remaining in the intake manifold that can get sucked into the engine. If this extra fuel gets into the engine while off-throttle, it creates a rich air-fuel mixture ratio. This will worsen the emissions.
With the ECU delaying the throttle, this allows air to mix with the remaining fuel. Resulting in a more balanced ratio, thus keeping emissions to an acceptable level. Jason Fenske perhaps can better explain this:
Most people probably wouldn’t notice this. But car enthusiasts are likely to notice and will find this annoying. Cars with direct injection are less likely to have rev-hang, or at least, it won’t be as noticeable. Port injection engines meanwhile inherently need rev-hang to better control emissions.
How To Rev Match: Wrap Up
That is our ultimate guide to rev-matching! To summarize, rev-matching is the act of blipping the throttle as you downshift. This matches the RPM that the engine would be at once it engages the lower gear, resulting in a smoother gear change which will reduce stress on the drivetrain.
Meanwhile, heel and toe is a method of rev-matching that allows you to shift down, rev-match, and brake the car all at the same time. This is a very popular method used by racing drivers in racing leagues where they still drive race cars with a manual transmission. This method helps them to control the car, thus improving lap times.
Rev-matching isn’t necessary, but it can make driving on the road feel smoother. Find a safe space to practice it for the first time and good luck!