When your car is fishtailing you should?
What is trailer sway and how do you stop it?
Trailer sway, or fishtailing, is when a trailer begins to move from side-to-side on its own, eventually resulting in flipping and (sometimes) turning the towing vehicle over, too. You can see an example in the video below.
It doesn’t happen on vehicles with a fifth wheel attachment, such as an articulated truck, only on vehicles where the towing connection (hitch) is well behind the rear axle.
As you can see in the video above, trailer sway is made worse when the load balance causes too much weight over the rear of the trailer and not enough weight over the trailer’s hitch. A minimum of 10-12% of the trailer’s weight should be over the trailer’s hitch. If a lot of weight as at the back, it acts as a pendulum. It’s important not to overload the hitch, though. Check out our guide to towing.
It’s also important not to exceed the maximum towing weight specified by the manufacturer, and for people who have no experience towing to avoid towing a trailer that’s heavier than the towing vehicle.
What causes trailer sway?
Trailer sway is usually set off by a strong gust of wind, either from a side wind in exposed areas or from a passing truck, and quick changes of direction such as on winding mountain roads. It’s made worse by incorrect air pressure in the trailer’s tyres, and the driver trying to correct it but not reacting fast enough.
The risks can be dramatically reduced by:
- Loading your trailer keeping heavy items down low and near the centre of gravity
- Pumping your tyres to the correct pressure
- Anticipating adverse conditions and slowing down in time (large trucks coming towards you or overtaking you, particularly road trains), exposed bridges with strong crosswinds, and coming out of the lee (wind shadow ) of a building or geographical feature.
Stopping trailer sway with trailer sway mitigation
This video shows how trailer sway mitigation works.
Trailer sway mitigation automatically controls the braking of the tow vehicle’s wheels independently to counter the forces of the fishtailing trailer.
Stopping trailer sway without electronic intervention
If you can apply the trailer brakes separately, do this immediately as that will drag the trailer back into line.
Take your foot off the accelerator but do not apply the brakes unless you’re at risk of hitting someone.
Steer gently against the motion of the trailer. As you slow down, the trailer will stop swinging so violently.
The risk of you losing control will depend on the overall weight of the trailer in relation to the towing vehicle. A light trailer will have less impact on how the towing vehicle moves, and vice versa.
There are special towing hitches with more friction that can help reduce the risk of trailer sway.
How should a trailer handle?
Strong crosswinds will push the vehicle sideways, even out of the lane if the driver isn’t quick enough, but they shouldn’t start the trailer swaying, even though up to 1500kg of force could be applied to the side of something like a caravan!
If you are doing everything right but your trailer is still swaying then you need to get it checked out as there may be an underlying problem.
Darren is an expert on driving and transport, and is a member of the Institute of Advanced Motorists
Fishtailing
Fishtailing is a vehicle handling problem which occurs when the rear wheels lose traction, resulting in oversteer. This can be caused by low-friction surfaces (sand, gravel, rain, snow, ice, etc.). Rear-drive vehicles with sufficient power can induce this loss of traction on any surface, which is called power-oversteer.
During fishtailing, [1] the rear end of the car skids to one side, which must be offset by the driver counter-steering, which is turning the front wheels in the same direction as the skid, (e.g. left if the rear swings left) and reducing engine power. Over-correction will result in a skid in the opposite direction; hence the name. Without a proper driver’s reaction, the fishtailing vehicle will spin completely.
Friction is the main reason this action is effective. If a car is moving across a surface in any direction other than the direction it is pointed, it is skidding (or sliding), and a sideways load is being imposed against the tires. This causes a lot of friction, even if the tires are allowed to rotate freely. By turning the front wheels into the direction of the skid, the front wheels will become aligned with the direction of travel. The side load will no longer be imposed against the front tires, and they will then roll freely to match the speed of the vehicle. This reduces the friction between the front tires and the surface. But the rear tires will still be sliding sideways, and the greater friction that exists will cause the back end to trail directly behind the front end, similar to a shuttlecock in flight, thus the car straightens out. As the car straightens, the front wheels must be kept aligned with the direction of travel to keep the friction of the front tires at or below the friction of the rear tires, or a skid in the opposite direction will quickly develop. The key is to keep the front wheels aligned with the direction the vehicle is moving-not the direction it is pointed. [ clarification needed ]
Most modern rear-wheel-drive cars solve this problem by using a form of traction control which limits engine power when fishtailing occurs. The ability of the rear suspension to keep tires in contact with, and perpendicular to the road is also a key factor in the amount of grip available through the rear axle. For example, a live beam axle suspension will have far less grip on a bumpy road than an independent rear suspension, due to its far greater unsprung weight, [ further explanation needed ] and forces from one wheel being transmitted through the axle to the other wheel, leading to the tire being out of contact with the road surface more of the time
Similar behavior is evident during heavy braking in all types of road vehicles, due to weight transfer to the front. This can be mitigated by re-proportioning the braking forces (more to the front, less to the rear) to keep the rear wheels from locking up. Most modern cars use anti-lock brakes (ABS) which addresses this problem. Older cars may have less sophisticated technical systems for lessening this tendency or the driver alone must actively modulate the brakes.
Fishtailing may be the result of the police pursuit technique called the PIT maneuver, in which the driver of a pursuing vehicle deliberately induces directional instability in a pursued vehicle with the intent of spinning it off the road.
See also [ edit ]
- Aquaplaning
- Black ice
- Doughnut (driving)
- Drifting, intentionally invoking a loss of traction as a motorsport maneuver
- Jackknifing
References [ edit ]
- ^«What is Fishtailing? » Oponeo.co.uk». www.oponeo.co.uk . Retrieved 2021-10-18 .
This Secret Trick Corrects Slide on Icy Road to Regain Control of Car
One of the most dangerous driving situations during the winter is a car that slides on a road with ice or snow. In my home state of Wisconsin, it’s not uncommon to see vehicles slide into the ditch. This is especially the case on the first snowstorm of the year — when drivers are a bit “rusty” with their winter driving skills. However, there’s a secret trick to correct a slide on an icy road so that you can regain control of your car. Read more to find out about this special technique.
How to prevent a car from sliding on a road with ice or snow
We’ll get to the secret trick in the next section, but first, let’s cover how you can prevent a car from sliding on a road with ice or snow. You can avoid it happening in the first place.
This mostly comes down to driving more slowly and avoiding any abrupt driving maneuvers. When drivers slide, also known as fishtailing, on an icy road and swerve into the ditch, it’s usually because they are driving too fast and aggressively for the conditions. They operate their car as if it’s a normal everyday driving situation.
However, on icy and snowy roads, you should limit your speed to 45 mph or less. Most slides and fishtails occur when driving at a speed of 45 mph or greater. It’s much more challenging to correct slides at higher speeds, for it requires precise and very quick steering. Furthermore, you should avoid any quick bursts of acceleration, abrupt braking, and sudden turns. All of these things increase the likelihood of sliding on ice and snow. Additionally, leave extra stopping distance behind other vehicles.
To correct fishtailing, ‘turn into a slide’ in the same direction that the rear of the car is sliding
OK, here’s the secret trick to correct a slide on an icy road so that you can regain control of your car. It’s called “turning into a slide.” While two types of slides are oversteer and understeer, the vast majority of cases are oversteer. And for oversteering, turning into the slide is an action that will fix the problem, as detailed by Icy Road Safety.
Turning into the slide means turning the steering wheel in the same direction that the rear of the car is sliding. This technique might sound counterintuitive, but it works. You can view this technique in the Icy Road Safety YouTube video below or in the above screenshot from the video.
If the back of your car slides to the left, then turn the steering wheel to the left. And if it veers to the right, turn it to the right. Once your vehicle straightens out on the road, straighten the steering wheel.
