Mid-engine design

The mid-engine, rear-wheel-drive format can be considered the original layout of automobiles. A 1901 Autocar was the first gasoline-powered automobile to use a drive shaft and placed the engine under the seat. This pioneering vehicle is now in the collection of the Smithsonian Institution.^[1]

The Lotus Europa S1 was based on a prototype built to compete for Henry Ford II's contract to build a Le Mans race car in the early 1960s.

Mounting the engine in the middle instead of the front of the vehicle puts more weight over the rear tires, so they have more traction and provide more assistance to the front tires in braking the vehicle, with less chance of rear-wheel lockup and less chance of a skid or spin out. If the mid-engine vehicle is also rear-drive the added weight on the rear tires can also improve acceleration on slippery surfaces, providing much of the benefit of all-wheel-drive without the added weight and expense of all-wheel-drive components. The mid-engine layout makes ABS brakes and traction control systems work better, by providing them more traction to control. The mid-engine layout may make a vehicle safer since an accident can occur if a vehicle cannot stay in its own lane around a curve or is unable to stop quickly enough. Mid-engine design is also a way to provide additional empty crush space in the front of the automobile between the bumper and the windshield, which can then be designed to absorb more of the impact force in a frontal collision in order to minimize penetration into the passenger compartment of the vehicle.

In most automobiles, and in sports cars especially, ideal car handling requires balanced traction between the front and rear wheels when cornering, in order to maximize the possible speed around curves without sliding out. This balance is harder to achieve when the heavy weight of the engine is located far to the front or far to the rear of the vehicle. Some automobile designs strive to balance the fore and aft weight distribution by other means, such as putting the engine in the front and the gearbox and battery in the rear of the vehicle.

Another benefit comes when the heavy mass of the engine is located close to the back of the seats. It makes it easier for the suspension to absorb the force of bumps so the riders feel a smoother ride. But in sports cars, the engine position is once again used to increase performance and the potentially smoother ride is usually more than offset by stiffer shock absorbers.

This layout also allows the motor, gearbox, and differential to be bolted together as a single unit. Together with independent suspension on the driven wheels, this removes the need for the chassis to transfer engine torque reaction.

Underfloor mid-engine in a historical Hanomag truck chassis.

The largest drawback of mid-engine cars is restricted rear passenger space; consequently, most mid-engine vehicles are two-seat vehicles. The engine in effect pushes the rear passenger seats forward towards the front axle (if the engine is behind the driver). Exceptions typically involve larger vehicles of unusual length or height in which the passengers can share space between the axles with the engine, which can be between them or below them, as in some vans, large trucks, and buses. The mid-engine layout (with a horizontal engine) was common in single-decker buses in the 1950s and 1960s, e.g. the AEC Reliance. The Ferrari Mondial is to date the only successful example of a true mid-engined convertible with seating for 4 and sports car/supercar performance. A version of the Lotus Evora with a removable roof panel is anticipated but no definite date is known.

Like any layout where the engine is not front-mounted and facing the wind, the traditional "engine-behind-the-passengers" layout makes engine cooling more difficult. This has been a problem in some cars, but this issue seems to have been largely solved in newer designs. For example, the Saleen S7 employs large engine-compartment vents on the sides and rear of the bodywork to help dissipate heat from its very high-output engine.

Mid-engined cars are more dangerous than front-engined cars if the driver loses control - although this may be initially harder to provoke due to the superior balance - and the car begins to spin. The moment of inertia about the center of gravity is low due to the concentration of mass between the axles (similar to standing in the middle of a playground roundabout, rather than at the edge) and the spin will occur suddenly, the car will rotate faster and it will be harder to recover from. Conversely, a front-engined car is more likely to break away in a progressive and controllable manner as the tires lose traction.

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Hanomag

Hanomag

Hanomag was a German producer of steam locomotives, tractors, trucks and military vehicles in Hanover. Hanomag first achieved international fame by delivering numerous steam locomotives to Finland, Romania and Bulgaria before World War I and making of first tractor Hanomag R26 in 1924 in Germany. In 1925, they added automobiles to their line, additionally moving in 1931 into the production of construction machinery. Since 1989, the company has been part of the Komatsu company.

Axle

Axle

An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.

AEC Reliance

AEC Reliance

The AEC Reliance was a mid-underfloor mounted engined single-decker bus and coach chassis manufactured by AEC between 1953 and 1979. The name had previously been used between 1928 and 1931 for another single-decker bus chassis.

Ferrari Mondial

Ferrari Mondial

The Ferrari Mondial is a mid-engined, V8, grand tourer manufactured and marketed by Ferrari between 1980 and 1993 – with styling by Pininfarina and bodywork by Carrozzeria Scaglietti.

Lotus Evora

Lotus Evora

The Lotus Evora is a sports car produced by British car manufacturer Lotus. The car, which was developed under the project name Project Eagle, was launched on 22 July 2008 at the British International Motor Show. The Evora S was launched in 2010 with a supercharged 3.5-litre V6. A facelifted and more powerful Evora 400 model was unveiled at the 2015 Geneva Motor Show, followed by another more powerful variant, the Evora GT430, which was unveiled in 2017.

Saleen S7

Saleen S7

The Saleen S7 is an American hand-built, high-performance sports car designed and built by American automobile manufacturer Saleen Automotive Inc. Developed jointly by Steve Saleen for the initial concept, direction and engine, Hidden Creek Industries for resources and initial funding, Ray Mallock Ltd. (RML) for chassis, suspension and aerodynamics, and Phil Frank for the body and interior CAD design and development.

Super, sport, and race cars frequently have a mid-engined layout, as these vehicles' handling characteristics are more important than other requirements, such as usable space. In dedicated sports cars, a weight distribution of about 50% front and rear is frequently pursued, to optimise the vehicle's driving dynamics – a target that is typically only achievable by placing the engine somewhere between the front and rear axles. Usually, the term "mid-engine" has been primarily applied to cars having the engine located between the driver and the rear drive axles. This layout is referred to as rear mid-engine, rear-wheel drive, (or RMR) layout. The mechanical layout and packaging of an RMR car are substantially different from that of a front-engine or rear-engine car.

When the engine is in front of the driver, but fully behind the front axle line, the layout is sometimes called a front mid-engine, rear-wheel-drive, or FMR layout instead of the less-specific term front-engine; and can be considered a subset of the latter. In-vehicle layout, FMR is substantially the same as FR, but handling differs as a result of the difference in weight distribution.

Some vehicles could be classified as FR or FMR depending on the factory-installed engine (I4 vs I6). Historically most classical FR cars such as the Ford Models T and A would qualify as an FMR engine car. Additionally, the distinction between FR and FMR is a fluid one, depending on the degree of engine protrusion in front of the front axle line, as manufacturers mount engines as far back in the chassis as possible. Not all manufacturers use the Front-Mid designation.

FMR layout – Front Mid-engine / Rear-wheel drive

Front mid-engine position / Rear-wheel drive

Front mid-engine position / Rear-wheel drive

These cars are RWD cars with the engine placed between the driver and the front axle.

• Alfa Romeo 8C Competizione
• AC Cobra
• Aston Martin Vantage (2005), (2018), Vanquish, DB7, DB9, DB11, DBS V12, DBS Superleggera, One-77, and Rapide
• BMW Z1, Z8
• Cadillac XLR, Sixteen
• Chevrolet Corvette (second through seventh generations)
• Chrysler Firepower
• Bill Thomas Cheetah (used only one universal joint between transmission tailshaft housing and differential housing)
• Dodge A100 and Viper
• Ferrari 599 GTB Fiorano, 612 Scaglietti, F12 Berlinetta, 812 Superfast, GTC4Lusso T, California, Portofino, and Roma
• Ford Econoline (first generation)
• Honda S2000
• Jaguar E-Type, XK, and F-Type
• Lexus LFA
• Maserati Quattroporte V, GranTurismo/GranCabrio
• Mazda Bongo (second generation), RX-7, MX-5 and RX-8
• Mercedes-Benz SLR McLaren, SLS AMG and AMG GT
• Morgan +4, 4/4, Aero 8, Plus Four, Plus Six and Plus 8
• Nissan 350Z, 370Z, and Z
• Opel GT (original)
• Porsche 924, 944 and 968
• Shelby Daytona
• Toyota Previa (first generation) and 2000GT

• Most pre–World War II front-engine rear-wheel-drive cars

FM4 layout – Front Mid-engine / Four-wheel drive

Front mid-engine position / Four-wheel drive

This layout, similar to the above FMR layout, with the engine between driver and behind the front axle, adds front-wheel drive to become a four-wheel drive. An engineering challenge with this layout is getting the power to the front wheels past the engine - this would normally involve raising the engine to allow a propshaft to pass under the engine, or in the case of the Ferrari FF taking power from both ends of the crankshaft with two separate gearboxes.

• Toyota Previa All-Trac variant
• Ferrari FF/GTC4Lusso
• Jensen FF
• Hummer H1
• Willys MB
• Most early front-engine off-road cars

RMR layout – Rear Mid-engine / Rear-wheel drive

Rear mid-engine position / Rear-wheel drive

These cars use a traditional engine layout between driver and rear drive axle. Typically, they're simply called MR; for mid-rear (engined), or mid-engine, rear-wheel-drive layout cars.

• Alfa Romeo 4C
• Alpine A110 (2017)
• Apollo Intensa Emozione
• Ariel Atom
• Arrinera Hussarya
• Artega GT
• Aston Martin Valhalla and Valkyrie
• Autozam AZ-1
• BMW M1
• Chevrolet Corvette (C8)
• Consulier GTP
• DC Avanti
• DeTomaso Vallelunga, Mangusta, Pantera, Guara, P72
• Ferrari 308, 328, 348, F355, 360, F430, 458, 488, F8, 296 GTB, Berlinetta Boxer, Mondial, Testarossa, F40, F50, Enzo, FXX, LaFerrari, FXX-K
• Fiat X1/9
• Ford GT and GT40
• Genty Akylone
• Gordon Murray Automotive T.33, T.50
• Ginetta F400, G60
• Gumpert Apollo
• Hennessey Venom GT, Venom F5
• Honda Beat, NSX (NA1/NA2), and S660
• Jaguar XJR-15 and XJ220
• Koenigsegg CC8S, CCR, CCX, Agera, Regera, Jesko
• Lamborghini Miura, Countach, Diablo SV, Jalpa, Silhouette
• Lancia Stratos HF, Montecarlo
• Lotus Europa, Esprit, Elise, Exige, Evora, Emira
• Maserati Merak, Bora, MC12, MC20
• Mastretta MXT
• Matra Djet, 530, Bagheera, Murena
• Mazzanti Evantra
• McLaren F1, MP4-12C, 570S, 650S, 720S, P1, GT, Artura, Senna, Speedtail, Elva
• Mercedes-Benz CLK GTR
• MG F
• Mitsubishi i and i-MiEV (Rear Mid-engine transversely-mounted / Rear-wheel drive)
• Mosler MT900
• Nissan R390 GT1
• Opel Speedster
• Pagani Huayra, Zonda
• Pontiac Fiero
• Porsche 550, 914, Boxster/Cayman, Carrera GT, 911 GT1
• Prince R380
• Renault 5 Turbo, Clio V6 Renault Sport
• Rezvani Beast
• Ruf CTR3
• Ruf RK Coupe/Spyder
• Saleen S7
• Scuderia Cameron Glickenhaus SCG 003, SCG 004
• SIN R1
• Smart Roadster
• SSC Aero, Tuatara
• Toyota MR2/MR-S
• Vencer Sarthe
• Venturi Atlantique
• Volkswagen XL1
• W Motors Lykan HyperSport, Fenyr SuperSport
• Zenvo ST1, TS1 GT

M4 layout – Rear Mid-engine / Four-wheel drive

These cars use mid-ship, four-wheel-drive, with an engine between the axles.

• Ares Design Project1
• Audi R8
• BMW i8
• Bugatti EB 110, Veyron, Chiron, Divo, Centodieci
• Ford RS200
• Ferrari SF90 Stradale
• Honda Acty (4WD versions only), NSX (NC1), Z (1998-2002)
• Italdesign Zerouno
• Koenigsegg Gemera
• Lancia Delta S4
• Lamborghini Aventador, Centenario, Sián FKP 37, Countach LPI 800-4, Diablo VT series, Gallardo, Murciélago, Reventón, Huracán, Sesto Elemento
• Mercedes-AMG ONE
• MG Metro 6R4
• Panther Solo 2
• Peugeot 205 Turbo 16
• Porsche 918 Spyder
• Volvo L3314
• Unimog UGN/405

MF layout – Mid-engine / Front-wheel drive

Front mid-engine position / Front-wheel drive

These cars are "mid-ship engined" vehicles, but they use front-wheel drive, with the engine in front of the driver. It is still treated as an FF layout, though, due to the engine's placement still being in the front of the car, contrary to the popular belief that the engine is placed in front of the rear axle with power transferred to the front wheels (an RMF layout). In most examples, the engine is longitudinally mounted rather than transversely as is common with FF cars.

• BSA Scout
• Citroën Traction Avant, DS, SM
• Nissan GT-R LM Nismo
• Renault 4, 5, 16
• Saab Sonett Mk1
• Honda Vigor/Inspire 1989–1995
• Maserati Quattroporte II

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Alfa Romeo 8C Competizione

Alfa Romeo 8C Competizione

The Alfa Romeo 8C Competizione is a sports car produced by Italian automotive manufacturer Alfa Romeo between 2007 and 2010. It was first presented as a concept car at the 2003 Frankfurt Motor Show and later offered for sale for the 2007 model year. The name refers to the eight-cylinder engine (8C) and Alfa Romeo's racing pedigree. The company received over 1,400 orders for the 8C after the official announcement that the car would enter production. However, only 500 customers ended up with the 8C Competizione and another 329 with the 8C Spider, bringing the production total to 829 cars.

AC Cobra

AC Cobra

The AC Cobra, sold in the United States as the Shelby Cobra and AC Shelby Cobra, is a sports car manufactured by British company AC Cars, with a Ford V8 engine. It was produced intermittently in both the United Kingdom and later the United States since 1962.

Aston Martin Vantage (2005)

Aston Martin Vantage (2005)

The Aston Martin Vantage is a series of hand-built sports cars from the British automotive manufacturer Aston Martin. Aston Martin has previously used the "Vantage" name on high-performance variants of their existing GT models, notably on the Virage-based car of the 1990s. The modern car, in contrast, is the leanest and most agile car in Aston's lineup. As such, it is intended as a more focused model to reach out to potential buyers of cars such as the Porsche 911 as well as the exotic sports and GT cars with which Aston Martins traditionally compete.

Aston Martin Vantage (2018)

Aston Martin Vantage (2018)

The Aston Martin Vantage is a two-seater sports car built by British manufacturer Aston Martin since 2018. It replaces the previous model which had been in production for 12 years.

Aston Martin Vanquish

Aston Martin Vanquish

The Aston Martin Vanquish is a high-performance grand tourer introduced by British luxury automobile manufacturer Aston Martin in 2001 as a successor to the Aston Martin Vantage (1993).

Aston Martin DB7

Aston Martin DB7

The Aston Martin DB7 is a car which was produced by British marque Aston Martin from September 1994 to December 2004. It was designed by Ian Callum and Keith Helfet as a grand tourer in coupé and convertible bodystyles. The prototype was complete by November 1992 and debuted at the Geneva Motor Show in March, 1993. The six-cylinder DB7 was positioned as an "entry-level" model below the hand-built V8 Virage introduced a few years earlier. This model was the most-produced Aston Martin automobile up to that point in time, with more than 7,000 built before it was replaced by the DB9 in 2004.

Aston Martin DB9

Aston Martin DB9

The Aston Martin DB9 is a grand tourer produced by Aston Martin. Available both in coupé and a convertible bodystyles, the latter being known as the Volante, the DB9 was the successor to the DB7. It was first shown at the 2003 Frankfurt Auto Show, and was the first model built at Aston Martin's Gaydon facility.

Aston Martin DB11

Aston Martin DB11

The Aston Martin DB11 is a grand tourer produced by British luxury car manufacturer Aston Martin since 2016. It debuted at the Geneva Motor Show in March 2016 as a replacement to the DB9. It is the first model launched in Aston Martin's 'second century' plan and the company's tie-up with Daimler AG.

Aston Martin DBS V12

Aston Martin DBS V12

The Aston Martin DBS is a high-performance grand tourer based on the DB9 and manufactured by the British luxury automobile manufacturer Aston Martin.

Aston Martin DBS Superleggera

Aston Martin DBS Superleggera

The Aston Martin DBS Superleggera, also sold as the Aston Martin DBS, is a grand touring car produced by British manufacturer Aston Martin since 2018. In June 2018, Aston Martin unveiled the car as a replacement to the Vanquish that is based on the DB11 V12 but featuring modifications that differentiate it from the DB11 lineage. The DBS name was previously used for a model built from 1967 to 1972 and for the DB9-based DBS V12 between 2007 and 2012. In addition, the car also uses the Superleggera name which is a reference to Carrozzeria Touring Superleggera, who helped Aston Martin develop their lightest grand tourers in the 1960s and 1970s.

Aston Martin One-77

Aston Martin One-77

The Aston Martin One-77 is a two-door, two-seater flagship sports car built by the British car manufacturer Aston Martin. The car was first shown at the 2008 Paris Motor Show, although it remained mostly covered by a "Savile Row tailored skirt" throughout the show. It was revealed in full at the 2009 Geneva Motor Show, and deliveries began in 2011.

Aston Martin Rapide

Aston Martin Rapide

The Aston Martin Rapide is a sports saloon car, built by the British marque Aston Martin from 2010 to 2020. It has four doors and four seats. It was first presented as a concept car at the North American International Auto Show in 2006 and the production version was shown at the 2009 Frankfurt Motor Show.