Rear-wheel drive
From WOI Encyclopedia Italia
Rear-wheel drive (or RWD for short) was a common engine/transmission layout used in automobiles throughout the 20th century. RWD typically places the engine in the front of the vehicle, but the mid engine and rear engine layouts are also used.
The vast majority of rear wheel drive vehicles use a longitudinally-mounted engine in the front of the vehicle, driving the rear wheels via a driveshaft linked via a differential between the rear axles. Some FR layout vehicles place the transmission at the rear, though most attach it to the engine at the front.
Rear wheel drive has fallen out of favor in passenger cars since the 1980s, due in part to higher manufacturing costs, and a perception by many car buyers that front wheel drive is safer, and that it performs better on slippery roads.
It still sees heavy use in taxi and police fleets, due to cheaper maintenance, and in the case of police fleets, better performance.
Contents |
Advantages
- Better handling in dry conditions - accelerating force is applied to the rear wheels, on which the down force increases, due to load transfer in acceleration, making the rear tires better able to take simultaneous acceleration and curving than the front tires.
- Less costly and easier maintenance - Rear wheel drive is mechanically simpler and typically does not involve packing as many parts into as small a space as does front wheel drive, thus requiring less disassembly or specialized tools in order to replace parts.
- No torque steer.
- Even weight distribution - The division of weight between the front and rear wheels has a significant impact on a car's handling, and it is much easier to get a 50/50 weight distribution in a rear wheel drive car than in a front wheel drive car, as more of the engine can lie between the front and rear wheels (in the case of a mid engine layout, the entire engine), and the transmission is moved much farther back.
- Towing - Rear wheel drive puts the wheels which are pulling the load closer to the point where a trailer articulates, helping steering, especially for large loads.
- Weight transfer during acceleration. (During heavy acceleration, the front end rises, and more weight is placed on the rear, or driving wheels).
- Drifting - Drifting is a controlled skid, where the rear wheels break free from the pavement as they spin, allowing the rear end of the car to move freely left and right. This is of course easier to do on slippery surfaces. Severe damage and wear to tires and mechanical components can result from drifting on dry asphalt. Drifting can be used to help in cornering quickly, or in turning the car around in a very small space. Many enthusiasts make a sport of drifting, and will drift just for the sake of drifting. Drifting requires a great deal of skill, and is not recommended for most drivers. It should be mentioned that front wheel drive and four wheel drive cars may also drift, but only with much more difficulty. When front wheel drive cars drift, the driver usually pulls on the emergency brake in order for the back wheels to stop and thus skid. This technique is also used for 'long' drifts, where the turn is accomplished by pulling the e-brake while turning the steering wheel to the direction the driver desires. With drifting, there is also the importance of 'counter-steering' - where while temporarily out of control, the driver regains it by turning the wheel in the opposite direction and thus preparing for the next turn or straight-away.
Disadvantages
- More difficult to master - While the handling characteristics of rear-wheel drive may be useful or fun in the hands of some drivers, for others, having the rear wheels move about is unintuitive and dangerous. Rear wheel drive rewards skill, and punishes the lack of it. Other layouts are much more forgiving, but don't offer the same rewards in handling.
- Decreased interior space - This isn't an issue in a vehicle with a ladder frame like a pickup truck, where the space used by the drive line is unusable for passengers or cargo. But in a passenger car, rear wheel drive means: Less front leg room (the transmission tunnel takes up a lot of space between the driver and front passenger), less leg room for center rear passengers (due to the tunnel needed for the drive shaft), and sometimes less trunk space (since there is also more hardware that must be placed underneath the trunk).
- Increased weight - The components of your typical rear wheel drive vehicle's power train may be less complex, but there are more of them. The driveshaft adds weight. The transmission is probably heavier. There is extra sheet metal to form the transmission tunnel. There is a rear axle or rear half-shafts. A rear wheel drive car will weigh slightly more than a comparable front wheel drive car (but less than four wheel drive).
- Higher purchase price - Probably due to more complicated assembly (the powertrain is not one compact unit) and added cost of materials, rear wheel drive is typically slightly more expensive to purchase than a comparable front wheel drive vehicle. This might also be explained by production volumes, however.
- More difficult handling on low grip surfaces (wet road, ice, snow, gravel...) as the car is pushed rather than pulled. This can make driving up a hill difficult. It can also lead to accidents in light rain. The decline in popularity of rear wheel drive cars can be attributed to these factors.
- Oversteer and the related problem of fishtailing.
Current or recent rear wheel drive cars to 2006
While the popularity of rear wheel drive has declined, it is still relatively prevalent, and has been making something of a resurgence. Here is list of current or recent rear wheel drive vehicles. See also Category:Rear wheel drive vehicles.
- Almost all non-4WD trucks and most SUVs are rear wheel drive.
- The overwhelming majority of sports cars are rear wheel drive, although some also have four wheel drive options. It would be redundant to list them all here.
- BMW - All cars except the MINI, and all wheel drive variants.
- Cadillac - CTS, SRX, STS, Catera
- Chevrolet - Camaro, Caprice, Corvette
- Dodge Charger/Dodge Magnum/Chrysler 300
- Ferrari
- Ford - Crown Victoria, Falcon (Australia), Mustang, Scorpio, Sierra, Thunderbird
- Holden - Holden Monaro (Australia) and versions sold overseas: Pontiac GTO (USA) and Vauxhall Monaro (United Kingdom), Holden Commodore (Australia)
- Honda - S2000, NSX (Acura NSX in North America)
- Hyundai - Hyundai Pony, Hyundai Stellar
- Infiniti - G35,M45,M35,Q45,M30,J30
- Jaguar - All except FWD and AWD X-Type
- Lexus - IS, GS, LS, SC
- Lincoln - Town Car and LS
- Lotus - All except Elan-M100
- Maserati - All models
- Mazda - MX-5 Miata, RX-7, RX-8
- Mercedes-Benz - All cars except A-Class, B-Class and all wheel drive models
- Mercury - Grand Marquis, Marauder
- Nissan - 350Z, Z Cars, Skyline (except 4WD models), Silvia (200SX in Europe/Oceania, 240SX in USA), 180SX
- Pontiac - Firebird, Solstice
- Porsche - All cars except the AWD Carrera 4, 911 Turbo and Cayenne
- Saturn Sky
- Toyota - Supra, MR2, Altezza (Lexus IS), Crown, Cressida (Mark II, Chaser, and Cresta internationally)
- TVR - All models
- Vauxhall Carlton/Opel Omega - All models
External links
- RearWheelDrive.org - An organization that is devoted to promote RWD
- "Why Front-Wheel Drive Sucks - And Why Rear-Wheel Drive is Coming Back" - A personal opinion
- What's It Like To Drive - Describes a test between two Dodge Daytonas, one FWD and one RWD
| Automobile layouts |
|---|
| Layouts: |
| FF | FMR | FR | MF | RMR | RR | F4 |
| Engine positioning: |
| Front-engine | Mid-engine | Rear-engine |
| Drive: |
| Front-wheel drive | Rear-wheel drive | Four-wheel drive | Six-wheel drive |
| Articles relating to Automobile configurations | |
|---|---|
| Car body style and classification | 2 plus 2 | Antique car | Cabrio coach | Cabriolet | City car | Classic car | Compact car | Compact performance car | Compact SUV | Convertible | Coupé | Coupé convertible | Coupe Utility | Crossover SUV | Custom car | Drophead coupe | Fastback | Full-size car | Grand tourer | Hardtop | Hatchback | Hot hatch | Hot rod | Large family car | Leisure activity vehicle | Liftback | Limousine | Luxury car | Microcar | Mid-size car | Mini SUV | Minivan | Multi-purpose vehicle | Muscle car | Notchback | Personal luxury car | Pickup truck | Retractable hardtop | Roadster | Sedan | Saloon | Small family car | Sport compact | Sports car | Sport utility vehicle | Spyder | Station wagon | Estate car | Supermini | Targa top | Taxicab | Touring car | Town car | T-top | Ute | Van | Voiturette |
| Specialised vehicles | Gyrocar | Flying car. Amphibious vehicle |
| Fuel technologies | Internal combustion engine | Electric vehicle | Neighborhood electric vehicle | Hybrid vehicle | Battery electric vehicle | Hydrogen vehicle | Fuel cell | Plug-in hybrid electric vehicle | Steam car | Alternative fuel cars | Biodiesel | Gasohol | Ethanol | LPG (Propane) | Homogeneous Charge Compression Ignition | Liquid Nitrogen | Gasoline Direct Injection |
| Driven wheels | Four-wheel drive | Front-wheel drive | Rear-wheel drive | All-wheel drive | Two-wheel drive |
| Engine positioning | Front engine | Rear engine | Mid engine |
| Layout | FF layout | FR layout | MR layout | MF layout | RR layout |
| Engine configuration | Internal combustion engine | Straight-6 | V engine | Wankel engine | Reciprocating engine | Inline engine | Flat engine | Flathead engine | Diesel engine | Two-stroke cycle | Four-stroke cycle | Pushrod engine | Straight engine | H engine | Turbodiesel | Hybrid vehicle | Rechargeable energy storage system | Electric vehicle | Hydrogen vehicle |
| Body | Framework | A-pillar | Bumper | Cabrio coach | Chassis | Crumple zone | Body-on-frame | Dagmar bumpers | Fender | Fender skirts | Grille | Hood | Hood scoop | Monocoque construction | Pontoon fenders | Quarter panel | Shaker scoop | Spoiler | Subframe | Tonneau |
| Doors | Butterfly doors | Gull-wing door | Scissor doors | Suicide door | |
| Glass | Sunroof | Greenhouse | Windshield | |
| Other | Antenna ball | Hood ornament | Japan Black paint | Nerf bar | Truck accessory | Bumper sticker | |
| Exterior Equipment | Lighting | Daytime running lamp | Headlamp | Headlight styling | Hidden headlamps | Retroreflector | Sealed beam | Trafficators | High intensity discharge |
| Other | British car number plates | Distance sensor | US and Canadian license plates | Vanity plate | Vehicle registration plate | Windscreen wiper | Windshield washer fluid | |
| Car engine | Air/Fuel | Air filter | Automatic Performance Control | Blowoff valve | Boost | Boost controller | Butterfly valve | Carburetor | Charge cooler | Centrifugal type supercharger | Cold air intake | Engine management system | Engine Control Unit | Forced induction | Front mounted intercooler | Fuel filter | Fuel injection | Fuel pump | Fuel tank | Gasoline direct injection | Indirect injection | Intake | Intercooler | Manifold | Manifold vacuum | Mass flow sensor | Naturally-aspirated engine | Ram-air intake | Scroll-type supercharger | Short ram air intake | Supercharger | Throttle body | Top mounted intercooler | Turbocharger | Turbocharged Direct Injection | Twin-turbo | Variable Length Intake Manifold | Variable geometry turbocharger. Warm air intake |
| Exhaust | Catalytic converter | Emissions control devices | Exhaust pipe | Exhaust system | Glasspack | Muffler | Oxygen sensor | |
| Cooling | Aircooling | Antifreeze | Ethylene glycol | Radiator | Thermostat | |
| Ignition system | Starter | Car battery | Contact breaker | Distributor | Electrical ballast | Ignition coil | Lead-acid battery | Magneto | Spark-ignition | Spark plug | |
| Other | Balance shaft | Block heater | Crank. Cam | Camshaft | Connecting rod | Combustion chamber | Crank pin | Crankshaft | Crossflow cylinder head | Crossplane | Desmodromic valve | Engine knocking | Compression ratio | Crank sensor | Cylinder | Cylinder bank | Cylinder block | Cylinder head | Cylinder head porting | Dump valve,Engine balance | Oil filter | Firing order | Freeze plug | Gasket | Head gasket | Hypereutectic piston | Hydrolock | Lean burn | Main bearing | Motor oil | Multi-valve | Oil sludge | Overhead camshaft | Overhead valve | PCV valve | Piston | Piston ring | Pneumatic valve gear | Poppet valve | Power band | Redline | Reverse-flow cylinder head | Rocker arm | Seal | Sleeve valve | Starter ring gear | Synthetic oil | Tappet | Timing belt | Timing mark | Top dead centre | Underdrive pulleys | Valve float | Variable valve timing | |
| Interior equipment | Instruments | Backup camera | Boost gauge | Buzzer | Car computer | Carputer | Check Engine light | Fuel gauge | Global Positioning System | Idiot light | Navigation system | Odometer | Speedometer | Tachometer | Trip computer |
| Controls | Bowden cable | Cruise control | Electronic throttle control | Hand brake | Manettino dial | Steering wheel | Throttle | Gear stick | |
| Motor vehicle theft deterrence | Car alarm | ESITrack | Immobiliser | Klaxon | Vehicle tracking system | VIN etching | |
| Passenger safety & seating | Airbag | Armrest | Automatic seatbelt | Bench seat | Bucket seat | Child safety lock | Dicky seat | Passive safety | Rumble seat | Seat belt | |
| Other | Air conditioning | Ancillary power | Car audio | Car phone | Center console | Dashboard | Motorola connector | Power window | Rear-view mirror | TripSense | |
| Powertrain | Wheels and Tires | All-terrain tyre | Bias-ply tire | Contact patch | Custom wheel | Drive wheel | Hubcap | Magnesium alloy wheel | Mud-terrain tyre | Paddle tires | Radial tire | Rostyle wheel | Run flat tires | Schrader valve | Slick tire | Spinner | Tire code | Tread | Treadwear rating | Whitewall tire | Wire wheels |
| Transmission | Automatic transmission | Clutch | Continuously variable transmission | Differential | Driveshaft | Electrorheological clutch | Epicyclic gearing | Fluid coupling | Fully-automatic transmission | Gear stick | Gearbox | Hydramatic | Limited slip differential | Locking differential | Manual transmission | Roto Hydramatic | Saxomat | Semi-automatic transmission | Semi-automatic transmission | Super Turbine 300 | Tiptronic Torque converter | Transmission (mechanics) | Transmission Control Unit | Turbo-Hydramatic | Universal joint | |
| Steering | Ackermann steering geometry | Anti-lock braking system | Camber angle | Car handling | Caster angle | Oversteer | Power steering | Rack and pinion | Toe angle | Torque steering | Understeer | |
| Suspension | Axle | Beam axle | Coil spring | De Dion tube | Double wishbone | Electronic Stability Control | Hydragas | Hydrolastic | Hydropneumatic suspension | Independent suspension | Kingpin | Leaf spring | Live axle | MacPherson strut | Multi-link suspension | Panhard rod | Semi-trailing arm suspension | Shock absorber | Sway bar | Swing axle | Torsion beam suspension | Transaxle | Trailing arm | Unsprung weight | Watt's linkage | Wishbone suspension | |
| Brakes | Anti-lock braking system | Disc brake | Drum brake | Hand brake | Hydraulic brake | Inboard brake | Brake lining | Brake fade | Brake fluid | Hydraulic fluid | Brake bleeding | Engine braking | Electronic brakeforce distribution | Regenerative brake |
