An enthusiast will choose a RWD over a FWD any-day. Why? Because it can drift, that’s why. And drifting is fun. Who wouldn’t agree right? But does that mean FWDs aren’t fun? Not at all.
The basic difference between FWD & RWD – Understeer and Oversteer
What do understeer and oversteer mean?
Imagine a car approaching a sharp turn on a single lane road, say a right turn. Given the proper speed, the car will successfully enter the turn, hold its line, and exit the turn as desired. No drama here. All completely safe. This is the ideal situation.
Now say that the car approaching the same turn has a FWD setup. And say it is accelerating while approaching the turn. What happens? Since it is a Front-Wheel-Drive car, its engine is connected only to the front wheels. When the car accelerates a little more than it should, the front wheels start losing traction and slip. The front end of the car slides out as a result of centrifugal force. It is not be able to hold its line and starts moving towards the left side of its lane. If not controlled at this time, it goes wide off-track. Since the car is not able to hold the line, or stay in its lane (because of the front end sliding out), it is said to understeer.
A car with a Rear-Wheel-Drive setup instead in the same situation behaves differently. Because the engine is sending all its power to the rear wheels, when over-accelerating, the rear end of the car will lose traction and slide towards the left side. In this case, the front end becomes a pivot point and the car ends up turning more than it should towards the right of the line. Hence the term oversteer.
Understeer vs Oversteer
What is drifting then?
Drifting is a controlled motion of oversteer in which the car is made to slide sideways with its front wheels totally in control with traction and grip. And the rear wheels going gaga with power and helping carry out the slide using excessive power and lack of traction. Most of us have watched movies like “The Fast and The Furious: Tokyo Drift” and we know how fascinating it is to watch a car drift. Hence in theory, only a RWD or a rear biased car has the ability to drift.
Quite frankly, how many times does one drift? Or how many people even try it? A regular person driving say a BMW will enjoy life from the small corner exits where the rear slides out a little bit. And that, isn’t limited to RWD setups.
Fun is totally subjective when it comes to driving. For some, a car needs to only be fast in a straight line. Others, a well handling one. For some, one that can hold its line while travelling down a fast corner. Others, one that can slide out its rear end. For some, it is commanding the raw power that is difficult to tame. For others, easy driveability. Most of these roles, a FWD setup can pull-off.
FWD setups don’t need a differential connecting the 2 rear wheels. Though, to make them more interesting, they are installed with Electronic Limited-Slip differentials. This means the ECU (electronic control unit) on-board can analyse which tyre has more traction out of the 2, the rear left or the rear right. And can add more power to the one with more traction or brake the wheel having lesser traction. This way, either the left or the right tyres will always have traction instead of both tyres losing traction together. Applying calculated amounts of brake force on the inner wheel while turning makes it behave like a pivot point making the manoeuvre a lot easier. This technology is called Torque Vectoring System. Cleverly using this system at high speed corners allows FWD cars to mimic the oversteer that you get from a RWD car. Fun!
Looking at the safety perspective, engineers say that a FWD car is safer compared to RWD. When a FWD understeers, the only option to control it is to let go off the accelerator pedal and apply brakes because the front wheels that manoeuvre the vehicle are already sliding. While in a RWD, the driver thinks that he/she can control the oversteer through steering input because only the rear wheels are sliding here, but ends up losing control of the vehicle. This makes understeer favourable in situations like the one mentioned here (this situation occurs in the real world more often than not).
Both FWD and RWD have their pros & cons. And when it comes to fun, a RWD is still chosen. Yes! But with FWD setups being more common, cheaper, and lighter, they are also getting “funner”. So yes, FWD cars are also really interesting.