Car Advice

Torque steer explained

You’ve probably heard or read something in a car review about torque steer, but what is it and does it actually matter? Torque steer explained…

What is torque steer?

TORQUE STEER is the tendency of a vehicle to pull to either the left or right under acceleration.  You may notice when applying the throttle the steering wheel tug in your hands as the car tries to pull to one side. It is most common in front-drive vehicles, and caused by one side of the drivetrain being easier to turn that the other.

There are a whole of reasons that can cause torque steer, and most car companies spend a lot of money on design and fixes to keep their sporty front-drive cars from torque steering.  While torque steer can be caused or exaggerated by things like unequal inflation in the front tyres, it’s more commonly caused because of the nature of a front-drive car, the transversely mounted engine (as distinct from in line, facing forwards to backwards).

Most front-wheel drive vehicles have the engine, transmission and differential all wrapped up in one package. And because it’s all got to be stuffed in the engine bay with the engine in the middle of the two front wheels, the transmission and differential are pushed to one side, which means the half-shafts to each of the front wheels end up being unequal in length – and so they react to torque loads differently.

In short, this results in drive from the engine being transferred to one wheel more efficiently than the other, which is torque steer.  And because the front wheels are being driven as well as also dealing with the steering, you get the slight tugging at the wheel in some front-drive cars.

Should I care? Probably not. The only people that should worry about torque steer are car enthusiasts who own higher-powered front drive cars that they are intent on driving hard and fast. Everyone else can stop now and read something like this.

Is it dangerous? No. It would be if it was severe, but no modern roadcar has it bad enough to worry, and those with the potential for torque steer get plenty of engineering attention lavished on them with everything from suspension to power delivery tweaks to help keep the steering wheel straight under hard acceleration.

What does it feel like, what do I need to do? You probably don’t even notice it, because you’ll naturally apply the small amount of pressure to keep the car straight without even feeling anything unusual.  But in high-powered front drive cars you may notice, in the first couple of gears, a tugging or a tendency for the car to deviate off line. The more powerful the car and the more quickly you accelerate, the greater the torque steer.

If you’ve never experienced torque steer before, then find yourself a big wide open space where you can test the off-the-line acceleration in first gear without hitting anything or causing an accident, or being considered a hoon. Then, bring the car to a stop, take your hands off the wheel and give the throttle a decent but brief squeeze. If your car is a front driver you’ll have likely seen the steering wheel jerk to either the left or right and the car lurch to the corresponding side. That’s torque steer.

Obviously, depending on the surface you’re on, the effect can be exacerbated by the camber on the road – the road is slightly angled for drainage.

In the video below, you’ll see two instances of torque steer. One at low speed and one at higher speed. 

 
OK, I’m a sporty driver.  Why is torque steer bad? Torque steer is bad because you’re not just wasting power but also not getting all your power to the ground, and because the steering correction you need to make will mask other feedback the car is trying to give you.  It particularly hurts the feel of the car (and your laptimes) when accelerating out of second-gear corners.   Torque steer also means the car is more likely to run wide (power understeer) out of corners, particularly if you’re turning against the torque steer direction.
 
Some people like torque steer because it makes the car feel alive, but generally the view is it’s a Bad Thing.
 
 
How is torque steer fixed? Back in the day you had to do actual mechanical engineering such as reconfigure the engine bay so the driveshafts were equal, and/or tune with the suspension properly. If the driveshafts had to be unequal length you could make them different weights or thicknesses so they reacted to torque in the same way.
 
Today, the typical approach is the lazy fix for all inherent handling issues – electronics. Simply configure the power steering so that it cancels out the torque steer, or limit the torque in lower gears. Or gently apply a fractional bit of brake pressure to compensate on the appropriate wheel. It is tricks like all these which allow front-drive cars to behave more and more like rear-drivers, slowly increasing the amount of power that can reasonably be fed through the front wheels.
 
Can rear or all-wheel-drive cars torque steer? Yes, but that’s far less common as these vehicles tend to not have the unequal length driveshafts common in front-drive vehicles, and the torque steer effect is not directly felt through the steering wheel.   Also, under acceleration there is a rearward weight shift which typically makes steering lighter and twitchier as it reduces camber which in turn reducing the ability of the car to track straight – a problem for front-drive vehicles, less so for rear or all-wheel drive cars.
 
Does torque steer mean front-drive cars can’t be sportscars? No, it does not.  Torque steer is much more of a problem in people’s heads than it is in reality, particularly if you’re not going to take your car to a racetrack. There are many superb front-drive sports cars such as the Renault Megane, quicker Ford Focuses and Fiestas, some older Hondas and several cars from Peugeot. More on that here.
 
This article was originally published in 2015.


Robert Pepper

Robert Pepper

Robert Pepper is a motoring journalist, offroad driver trainer and photographer interested in anything with wings, sails or wheels. He is the author of four books on offroading, and owns a modified Ford Ranger PX which he uses for offroad touring. His other car is a Toyota 86 which exists purely to drive in circles on racetracks, and that's when he isn't racing his Nissan Pulsar. Visit his website: www.l2sfbc.com or follow him on Facebook https://www.facebook.com/RobertPepperJourno/ or buy his new ebook!