Limited slip differential vs an open diff

Limited slip differential vs an open diff

What is a limited slip differential - McLaren

Those who crave performance from their car won’t always need a helping hand from the engine – perhaps they’re after more control and traction in the corners.

This is exactly where something like a Limited Slip Differential (LSD) will come into the fray.

Versus an open differential, a limited slip diff is often a key factor in ensuring a car can make the most out of its potential.

What is a limited slip differential?

An LSD effectively does what it says on the tin, in so much that it limits slip through the distribution of torque throughout the drivetrain.

In doing so, it can effectively improve traction and vehicle stability in the corners, but also help out in tricky conditions such as in heavy rain or mud.

Through the likes of the gears, clutch and other such components, the LSD can limit the speed difference between the wheels that power is sent to. This can also be achieved electronically.

A limited slip differential is very particular as to where it will send the power and, most notably, will look to give the most power to the wheel with the most traction available.

What makes an LSD better than an open differential?

While a limited slip differential is clever in the way it distributes torque, an open differential is a little more free spirited with this process.

Torque is split evenly between the wheels when it comes to an open differential – if your car with an open diff starts to struggle in tough conditions, instead of looking for which wheel has the most traction, it will send the majority of power to the wheel with the least resistance.

In such circumstances, this will only lead to spinning wheels and further reduced traction.

With a limited slip differential, traction is optimised by offering the most torque to the wheel(s) with the most grip available.

Other benefits of a limited slip differential

While enhanced traction is typically the first call for adding an LSD to a car, a limited slip differential comes with additional benefits:

  • Increased stability

Traction is one thing, but having a car that can be more stable during high speed or entering into a corner is also vitally important if piloting a performance vehicle.

Having an LSD on board means you expect to find your car much more predictable under a range of conditions.

  • Better overall performance

Especially when it comes to acceleration, a limited slip diff can be very handy to ensure the power gets put into the tarmac and not any spinning wheels, as your tyres burn away, which leads nicely onto…

  • Reduced tyre wear

Preventing wheel spin in general is very useful for the preservation of your tyres – an LSD will go a long way to helping keep costs down on rubber when keeping wheel spin to minimum.

  • Off-road capability

It’s not just about sports and supercars when we discuss limited slip diffs – LSDs can be found in a huge range of off-road vehicles that offer (proper) four-wheel drive to help distribute torque intelligently.

Types of limited slip differentials

You may come across different setups when it comes to limited slip diffs, typically coming with their own set of pros and cons.

  • Mechanical limited slip differential

This is the type of LSD you may find further down the pecking order in the automotive hierarchy.

A mechanical limited slip differential uses gears and clutches to limit slip through the drivetrain. While typically reliable and a great addition to the likes of a hot hatch, a mechanical LSD can wear out over time.

  • Electronic limited slip differential

On higher end cars, you may find yourself an electronic LSD is on offer. Using electronic sensors to manage power distribution, this set up is incredibly efficient at ensuring slip is minimised.

What makes an electronic limited slip diff so effective is its ability to adapt and offer quick-witted tweaks during changeable conditions.

  • Viscous limited slip differential

Perhaps not seen in many vehicles, a viscous limited slip diff makes use of fluid to transfer torque between the wheels.

This type of limited slip differential is quite reliable, but watch out for overheating.

  • Torsen limited slip differential

A Torsen limited slip diff is serious business, and stands for torque-sensing limited slip differential.

They offer an advanced and robust design to very effectively transfer torque throughout the drivetrain, with a Torsen limited slip differential making use of a unique worm gear design.

This set of helical worm gears are positioned between the drive wheels of an axle – when a wheel begins to lose traction and starts to slip, these worm gears engage to redistribute the torque appropriately.

Made out of sterner stuff, a Torsen limited slip differential is highly durable and requires next to no maintenance. However, it’s not advised to utilise this style of LSD for any sort of extreme off-roading.