What Is Tank Slapper?

The automotive community creatively uses phrases and terms to describe their cars and how they behave. These phrases can often be strange or may not entirely make sense to everyone. One such phrase is tank slapper, and many people outside of the motoring community don’t know what it means.

Tank slapper is a term used in the automotive world to refer to a loss of traction. Normally a loss of traction requires the driver to correct the steering in order to regain control of the car or motorcycle. Tank slappers can happen under harsh acceleration or at high speeds.

The term tank slapper technically does not make sense in car terms though. The phrase actually originated from motorbikes and has been adopted into the automotive dictionary as a whole, so let’s dig a little deeper to find out where the term tank slapper comes from.

Where Did The Term Tank Slapper Come From?

Losing Traction

The term tank slapper originated in the world of motorcycles. It refers to a ‘speed wobble’ that you would get either while accelerating or even at high speeds on the bike. You may even have experienced it on a bicycle before, but to a much lesser extent.

When a bike gets a speed wobble the steering tends to swing left and right as the bike struggles to find traction and grip with the front tire. This swinging effect on the steering can sometimes be so extreme that the handlebars actually hit the side of the fuel tank. This was then coined a ‘tank slapper’.

So, in terms of cars, this doesn’t make sense, yet it’s still used very often. It’s often used to describe losing traction in a car, in other words if you accelerate heavily and need to counter steer in order to keep the car going in a straight line.

Counter Steering

The correct term for this is counter steering or corrective steering. With inexperienced drivers, or under difficult driving conditions, it is possible to over-correct. This is where the driver or rider counter steers against the slide in order to correct the car back into a straight line, but they apply too much steering angle and end up spinning in the other direction.

Is Tank Slapper A Common Occurrence?

In terms of bikes a tank slapper is a relatively common occurrence. It can be an extremely dangerous situation. It’s also referred to as a ‘death wobble’ as it can be extremely difficult to recover from, especially at high speeds.

In cars it’s not such a common occurrence. Unless you are driving the car extremely aggressively or trying to drift the car, you shouldn’t ever lose traction in this way. In normal driving on public roads, you will never experience a tank slapper. If you watch any motorsports however, you will see it more often.

In Motorsport

It’s rather common in Formula 1 where drivers are really pushing their cars to the limit. It’s much easier to see how they control and recover from a tank slapper from the onboard camera. It’s not only common in Formula 1 though, as you can also see it happen in IndyCar, NASCAR, WEC and most other motorsports.

You can clearly see a tank slapper in motorsport from all the different camera angles. A tell-tale sign of it is when a car’s front wheels are pointing in one direction, and the driver’s steering wheel is pointing the other direction.

What Causes Tank Slapper?

In a car, a tank slapper can be caused by a variety of factors. The end result is always a loss of traction. In other words, the tires lose grip or even contact with the tarmac. It usually only happens when the car is being driven very fast or very aggressively.

Bad Weather

Adverse weather conditions can really affect the traction that the car gets on the tarmac, not only under acceleration, but also at high speeds. For example, rain and snow can heavily affect grip levels. A tank slapper at high speeds in the rain would be called aquaplaning.

Aquaplaning is essentially when water comes between tires and the surface of the road, causing the tire to lose contact with the tarmac resulting in a loss of control. The same goes for mud, dust and sand on road surfaces.

Harsh Acceleration

Heavy acceleration is the most likely factor to cause a tank slapper in a car. However, this is only likely to happen if you have the traction control turned off . Without traction control there is no electronic throttle control, and if you accelerate slightly too hard out of a corner the driven wheels can easily lose traction resulting in a tank slapper.

Bumpy Roads

Bumps in the road can easily cause a quick loss in traction at any speed. The bumps cause the tires to lift off the ground which will result in them spinning up for the fraction of a second that they are in mid-air. When the tires contact the ground again, their rotating speed will be much faster than the traveling speed resulting in a similar situation as heavy acceleration.

Bumps can also easily destabilize the car and cause a tank slapper if the driver is unable to control the speed and angle of the car over bumps.

Worn Tires

Tire wear can also cause tank slappers. Heavily worn tires lose their grip very easily because they don’t have enough tread left. The tread on the tire is what allows the tire to stick to the tarmac and to push water out of the way of the wheels in bad weather, and once that tread is running low or even gone it can result is a massive loss of grip.

Road Surfaces

Road surface conditions will affect the grip of the car as well. If the surface of the tarmac is in poor condition it means that the grip levels will also be lower. This can be anything from worn out tarmac to potholes in the road. These can easily cause an unexpected tank slapper.

How To Control A Tank Slapper

A tank slapper can be an extremely scary moment for an inexperienced driver. Knowing how to control your car in a situation like this is crucial to saving your car and possibly even your life. Luckily, these situations can be practiced, and you can learn how to prevent and get out of a tank slapper.

Catch The Drift

The correct way to control a tank slapper is to firstly lift off the throttle. The amount you lift depends on the severity of the traction loss. In some cases, a small lift of around 20% will work to stop the driven wheels from spinning. In more severe cases you may have to lift off the throttle entirely.

The next step is to counter steer in the opposite direction to which the car is sliding. The idea here is to get the front wheels to direct the car back into a straight line. Again, the amount of counter steering angle required to correct the car depends on the severity of the slide. In most cases, the front wheels will have enough grip to redirect the car without too much counter steering.

Gentle Braking

In more severe cases, it can help to apply a small dab of brakes along with counter steering. F1 driver Max Verstappen does this very well, and there are some great examples of how he uses counter steering along with the brakes in order to get the car back into a straight line in the middle of F1 races, where the speeds far exceed those experienced by anyone on the road.

Applying the brakes while steering in the opposite direction helps the front tires to grip back on to the tarmac by slowing them down and allowing them to regain traction.

Practice Makes Perfect

The first way you can practice this is to purposefully put yourself in this kind of situation (in a safe environment of course).Think of it as exposure therapy. If you are able to recreate a tank slapper and practice correcting it, it will be less of a surprise when it actually does happen, and you will know how to control your car.

Advanced Driving Classes

Various manufacturers such as Audi, BMW and Mercedes-Benz offer advanced driving courses. The courses themselves will improve your driving skills overall, but there is one particular test that helps you to perfect your car control.

This test involves what is called a skid pan. You will essentially be put on a large open piece of tarmac (like a car park). Sprinklers will then be used to wet the surface of the road making it extremely slippery. You will then be sent out in a powerful car with traction control disabled.

The idea is to try and drift the car or power slide in order for the driver to experience what it’s like being in a car that is on the limit of control. Most drivers will spin and lose control of the car right away. However, the instructor is there to guide you through the entire process and teach you how to keep the car under control.

Safety Is Key

I would like to stress how crucial it is to practice these skills in a safe environment (like an empty racetrack or on private land) with a trained professional. Attempting this on your own or on public roads is extremely dangerous, and you could not only put your own life in danger, but other lives as well.

Final Thoughts

A tank slapper is a term that has been ‘stolen’ from the motorcycle community. The phrase is used when a car loses traction or grip either during hard acceleration or at high speeds and requires the driver to correct the car. It can be a dangerous situation to be in if the driver is inexperienced, but luckily these are not a common occurrence in road cars.