With only a few exceptions, most normal cars have four wheels. Over the past couple weeks, we’ve seen exactly how an engine makes power, sends it through the drivetrain, and translates it to the wheels of a car, truck, or SUV. But, every car is a little different.
Some cars are driven by the front wheels, some are driven by the rear-wheels, and some are driven by all the wheels, whether all the time or only some of the time. The engine also has to be placed somewhere to drive those wheels. Engine placement means a lot, and the setup varies by vehicle.
Which is best though? There has to be a reason that each car is set up differently. Why are most everyday family sedans driven by the front wheels? Why are so many pickup trucks rear-wheel drive with the option of four-wheel drive? Why do many supercars have the engine behind the driver?
These are the questions we are going to answer for you. Every setup has its advantages and disadvantages, and we are going to look at a few of those right here, right now. Let’s get into it:
Front-Engine Layouts:
Technically speaking, a front engine car is a car whose engine is located in front of the front axle. One of the heaviest parts of the car is its engine, and the center of its mass determines the vehicle’s layout.
Some “front engine” cars actually cheat a little bit, though. People tend to classify the engine layout of a car by its relation to the occupants rather than in relation to the axles. As a result, some “front engine” cars are technically mid-engine cars, with the engine being just slightly behind the front axle.
For our own purposes, and for most everybody else, this setup is still considered a front-engine layout.
Many front-wheel drive cars have engines that are mounted transversely – sideways – so there is room for the passenger. The farther back the engine is placed, the less room there is for occupants.
Front Engine/Front-Wheel Drive:
Most modern everyday sedans, many SUVs, and most minivans have this type of setup. Components don’t have to be as long or as many, because the engine, transmission, and driveshafts are all there in the same place. This means that the layout is compact and simple.
The layout saves space for the occupants, because the transmission is beside the engine, not behind it. Front wheel drive cars also have an advantage over rear-wheel drive cars in bad weather. The engine’s weight provides added traction to the front tires.
A disadvantage of front engine layouts and front wheel drive comes in the performance department. Asking the front two wheels of car to drive and turn it at the same time is quite a lot. Accelerating quickly also comes with a price as traction is decreased when weight shifts toward the back of the car.
Front Engine/Rear-Wheel Drive:
This was the traditional layout in cars for decades. It’s simple and durable. It also provides a bit more weight balance to the car, because components are more spread out over the car’s entire length.
Sports cars and pickup trucks favor this setup today. For sports cars, it’s the ideal layout. The rear wheels are pushed against the pavement under hard acceleration as the weight of the car moves backwards. Rear-wheel drive also allows for better handling through a corner… More on that later.
Pickup trucks are rear-wheel drive because they need some amount of weight in the back to keep them stable when driving. Sure, the wheels and tires provide some weight, but in a vehicle that size, the weight of just the wheels and tires don’t do much by themselves.
Even with rear-wheel drive, pickups often need items added to the bed during bad weather to give better traction.
Front Engine/All-Wheel Drive:
This layout comes with just about all the advantages and disadvantages of everything we’ve already mentioned.
Many modern SUVs make do with this setup, but many also have part-time all-wheel drive systems. Most Subarus, the Volkswagen Alltrack, and most Audi models have full-time all-wheel drive. Even then, most all-wheel drive systems are biased toward a front-wheel drive setup.
Some high performance cars also take advantage of this setup. The Nissan GT-R, BMW M5, and Jaguar F Type SVR are all-wheel drive and take full advantage of the ferocious acceleration times that all-wheel drive traction provides. Top speed reduction, overall handling, and weight are the disadvantages that come with an all-wheel drive performance car.
For most other cars, inclement weather is easily overcome with an all-wheel drive system, however, weight also reduces overall efficiency.
Mid-Engine Layouts:
Mid-Engine layouts are most popularly found in supercars and hypercars. Lamborghini, Ferrari, and McLaren supercars all utilize this setup, mainly for balance.
Because the engine is situated between the driver and the rear axle, the weight of the engine moves the center of gravity toward the inside of the vehicle, and it creates a car with supreme handling capabilities.
Mid-Engine/Rear-Wheel Drive:
Photo: Courtesy of Supercars.net
The traditional supercar has a mid-engine, rear-wheel drive setup. Again, most supercars that you can think of including Lamborghini, Ferrari, and others have this setup. Being rear-wheel drive allows some oversteer and better handling than even an all-wheel drive car that is also mid-engined.
Mid-Engine/All-Wheel Drive:
Some manufacturers add all-wheel drive systems to their supercars. The Audi R8 is a great example. Not too much is lost in the handling department because of the engine placement, but acceleration is improved over a traditional rear-wheel drive car.
Cars with a mid-engine, all-wheel drive setup add the acceleration that any all-wheel drive cars would also have, but they also don’t compromise in terms of handling. The Lamborghini Huracan, Honda NSX, and Bugatti Chiron are some other cars with this type of layout.
Rear-Engine Layouts:
I’m sure you’ve seen drag races before. Cars have wheelie bars attached to the back in order to keep the nose of the car from popping up during acceleration. Some cars still do wheelies because of the power they produce! Not only that, but most drag cars have their heavy engines in front of the driver!
Now, picture a car that’s rear-wheel drive, with the engine behind the rear axle. It would be like putting an engine as far back in your family’s trunk as it could possibly go. You’d think the layout wouldn’t be ideal for too many things, including performing on the track and the street. Porsche thinks otherwise.
Rear Engine/Rear Wheel Drive:
The Porsche 911 is the most famous car to utilize this setup. As you’d guess, it wasn’t the best in terms of its handling characteristics. With all the weight in the back of the car, I don’t have to explain too much further what could and did happen if you didn’t know how to drive one.
Or, you could think about the Chevy Corvair, a car famous for being one of the most dangerous cars ever made because its engine was in the rear, causing the car to randomly spin out and crash. That wasn’t the case all the time, but that’s the stigma that remains today.
You may also have heard of the Volkswagen Beetle – the classic Beetle, of course. It too had a rear-engine, rear-wheel drive setup.
Rear Engine/All-Wheel Drive:
Times have changed, and Porsche has changed. The addition of all-wheel drive to many of their rear-engined cars has proven to vastly improve handling. Think of it as a pickup truck, but the other way around.
The all-wheel drive system components are spread out over the entire length of the car, providing a little more weight over the front wheels, and thus, providing better handling. Of course the weight of the engine, along with the traction of all wheel drive, improves acceleration.
The Bottom Line:
Front-engine, front-wheel drive cars are cost effective and easy to drive. They are mostly used in minivans, family sedans, and some SUVs.
Front-engine, rear-wheel drive is the best setup for pickup trucks and sports cars. Pickup trucks need some weight in the rear of the vehicle to keep them stable. Sports cars favor rear wheel drive for acceleration and handling purposes.
All-wheel drive delivers added bad weather usability for SUVs and cars, and it adds acceleration and grip in high performance cars. Weight and a reduced top speed are enemies of all-wheel drive. All-wheel drive is compatible with any engine position.
Mid-engine, rear wheel drive is the most suitable for the highest performing cars. It provides stability, balance, and the capability for high speeds.
But wait… there are two more things we need to discuss really quickly. We’ve already mentioned oversteer, but what is it? Let’s find out:
What is Oversteer?
Oversteer occurs when a vehicle is going around a corner and the rear tires of the vehicle lose traction, causing it to “drift”. Rear-wheel drive vehicles can accomplish this fairly easily under enough speed, power or both.
With the tires already under stress from taking a corner quickly, additional throttle can be added to further decrease the traction of the rear wheels in a rear-wheel drive car. A good driver can control this slippage and cause the car to “drift.” The front wheels of a rear-wheel drive car can still steer the vehicle in whatever direction the driver intends, therefore creating a controlled turn.
Even front-wheel drive cars can achieve oversteer if the car is well-balanced. The back end usually has to be intentionally “thrown out” by the driver because the rear wheels are simply guiding the car rather than driving it forward. “Drifting” a front-wheel drive car can be achieved by an expert driver or in slippery conditions.
What is Understeer?
Understeer occurs most often in front-wheel drive cars. It’s when the front of car is pushed forward through a corner rather than easily turning.
This occurs because the front wheels of a car are both steering and driving the vehicle. Additionally, the weight of the engine places even more burden on the front wheels. This makes a vehicle resist turning through a corner easily under speed.
So which wheels are best to drive a car? There are quite a few answers to that. Each layout has its pros and cons. Most high performance cars favor a rear-wheel drive setup with the engine in the front or the middle. Most average cars have a front-engine layout with either front or all-wheel drive.
No matter your preference or needs, there is going to be a layout that is right for you. Just remember: Each layout provides different driving dynamics.
Chances are that you won’t notice any if you just use your car for a daily commute, but if you like to have fun every once in a while, be mindful of the differences.
