Science Fair Project Encyclopedia
The MR2's life began in 1976 when Toyota launched a design project with the goal of producing a car which would be both enjoyable to drive, yet still provide decent fuel economy. Initially, the purpose of the project was not a sports car, not to mention a mid-engined one. The actual designwork began in 1979 when Akio Yoshida from Toyota's testing department started to evaluate different alternatives for engine placement and drive method. It was finally decided to place the engine transversely in the middle of the car. The result was the first prototype in 1981, dubbed the SA-X. From its base design, the car began evolving into an actual sportscar, and further prototyes were tested intensely both in Japan and in California. A significant amount of testing was performed on actual race circuits such as Willow Springs, where former Formula One driver Dan Gurney tested the car.
Toyota made its SV-3 concept car public in the Autumn of 1983 at the Tokyo Motorshow, gathering a huge amount of publicity both from the press and the audience. The car, scheduled to be launched in spring 1984 in the Japanese market under the name MR2 (initially standing for "Midship Runabout, 2-seater" but later claimed to be "Mid-engine, Rear-wheel drive, 2-seater") was to become the first mass-produced mid-engined car to come from a Japanese manufacturer.
The small and light MR2, model AW11, was perhaps something no one had expected any of the Japanese car manufacturers, known for their economical and practical cars. The two-seat MR2 was definitely not practical as a family car, but the design criteria were different from that of most previous cars. The most important features of the AW11 were its light bodyshell, superior handling and relatively powerful small-displacement engine. Thanks to these features, the AW11 is very enjoyable to drive - its behavior mimics that of highly expensive supercars, still being both easy to control and nimble in its movements. Toyota's cooperation with Lotus during the prototype phase can be seen in the AW11, and it owes much to Lotus's legendary sportscars of the 1960s and 1970s.
As a powerplant, Toyota chose to use the 4A-GE 1600cc inline-four engine with two overhead camshafts (twincam) which allowed the use of 16 valves for a better gas flow through the combustion chamber. The engine was also equipped with a Bosch L-Jetronic type multi-point fuel injection and a variable intake geometry (T-VIS), giving the engine a maximum power output of 128 hp (95 kW). US-spec engines were rated at 112 hp (84 kW), Euro-spec at 124 hp (93 kW). The engine had already been introduced earlier on the sportier Corolla models (AE86 and AE82), gathering a lot of positive publicity. There was also a JDM model AW10 which used the more economical 1500cc 3A-U engine, but it didn't gain too much popularity.
For the 1986 model year, the AW11 went through several changes which affected both its looks and performance. The most important addition was probably having the option of a removable targa top. The exterior was modified by color-coding the bumpers and side stripes, adding small side skirts and a translucent spoiler to rear of the roof. Other new options included a leather interior and a four-speed automatic transaxle. Some further changes were made to the exterior the following year but more notable were the addition of larger brakes and a heavier C52 transaxle which replaced the older C50.
In 1988, Toyota brought a new choice for an engine for people longing for more power. Based on the same block and head, the 4A-GZE was equipped with a roots-type supercharger and therefore the compression ratio, valve timing and ports were modified. The engine produced a maximum power of 145 hp (108 kW) and accelerated the small car from 0 to 100km/h in 6.7~7.0s. In addition to the new engine, the MR2 SC was also equipped with stiffer stabilizer bars and reinforcements in the bodyshell to improve rigidity. Unfortunately, this model was never sold in European markets, although some cars were privately imported.
The press received the AW11 with open arms and praised its innovation, great feeling, and responsive engine. The American car magazines Road & Track and Car & Driver both chose the AW11 on their lists of ten best cars which included some really tough competition, such as the Ferrari Testarossa. The Australian Wheels magazine chose the 1988 AW11 as its favourite sportscar. The MR2 was Motor Trend's Import Car of the Year for 1985. In 2004, Sports Car International named this car number eight on the list of Top Sports Cars of the 1980s. The MR2 was on Car and Driver magazine's Ten Best list for 1986 and 1987.
The MR2 went through a complete renewal in 1989, when the new mk2 body was produced. The new MR2, model SW20, was longer, wider and heavier than its predecessor and had smoother bodylines. The wild and futuristically styled earlier model, comparable to a big go-kart, had evolved into a more mature and adult look and feel. While the AW11 was a pure sportscar, made in the spirit of Lotus, the SW20, being quite larger, could be classed as a GT-car. Since the resemblance between Ferrari 348tb and the new MR2 is quite striking, the SW20 can sometimes be heard to be referred as a "poor man's Ferrari".
When the SW20 went on sale in spring 1990, it was offered with four different engine choices depending on the market area. All engines were 2000cc four-cylinder inline engines with dual overhead camshafts and 16 valves, excluding the normally aspirated US model which uses the 2200cc 5S-FE engine. The most powerful engine was the turbocharged 3S-GTE , which was again only available in Japan at 220 hp (164 kW) (as the MR2 GT) and the USA at 200 hp (149 kW) (as the MR2 Turbo) so the Europeans had to settle with the normally aspirated 156 hp (116 kW) 3S-GE engine. The Japanese MR2 GT model was able to accelerate from 0-100km/h in a stunning 5.9~6.2s.
SW20's entry to the markets was not quite as smooth as AW11's. Toyota's goal was to make the car's suspension geometry to work the same way that true supercars do. This made the SW20's cornering abilities quite excellent, but it was much too easy for a driver with no experience driving mid-engined cars to make a mistake leading to sudden oversteer (also called "snap oversteer ") which can result in a spin unless the driver reacts both quickly and correctly. This trait was not considered very desirable among the press because the MR2, unlike expensive supercars, was priced so that even "average people" were able to buy one. Some magazines made overstatements where they claimed that the SW20 was downright dangerous to drive.
To respond to the feedback they had received, Toyota changed the 1992 model to include wider rear tyres and changed the rear suspension so that the car would be more prone to understeer, thus making it more difficult to push the car into snap oversteer. These changes also made the cornering abilities a bit worse, so for example autocross drivers prefer the first revision cars. Along with the suspension changes, the SW20 also got new 15" wheels to fit the larger brakes that were also introduced. Some shift problems which plagued the first revisions were remedied with stronger synchronization rings.
The next big change occurred in 1994, when SW20 received all-new engines for each model and some considerable changes to its exterior. For 3S-GTE the use a MAP-sensor , the removal T-VIS in favor of smaller intake ports and the new CT20B turbocharger increased the maximum power to 240 hp (179 kW). The normally aspirated 3S-GE received fewer changes but still improved its maximum power to 172 hp (128.3 kW). Having been an option earlier, limited-slip differential was introduced as standard to all turbocharged models. New round tail lights and a color-coded center panel replaced the old square-shaped lights and the rear grille. The original three-piece rear spoiler was replaced with the lighter one-piece spoiler which attaches only to the bootlid. The side stripes and -skirts were also color coded. In 1996, the front and side signals were changed to use a clear lens but no other modifications were made.
On SW20's last production year in 1998, the car was updated with a few significant changes. While the turbocharged engine remained the same, in JDM models the normally aspirated 3S-GE engine was equipped with Toyota's VVT-i system which allowed the timing of the intake camshafts to be modified according to the engine's rotation speed and load. This, and some other changes improved the engine's power output to a respectable 198 hp (148 kW). All models also received new wheels, sportier Recaro seats as an option and a three-way adjustable rear spoiler.
After having been in the market for almost ten years, SW20 had to move aside as Toyota released the new MR2 mk3, model ZZW30. The new MR2 was, in a way, return to the design concept of AW11 since the weight of the car was once again dropped below a metric tonne and it was significantly smaller than the SW20. The biggest change was, however, the replacement of either the solid or targa top with a convertible soft top, earning the car the 'Spyder' designation. In Japan, the car is called the MR-S, which purportedly is derived from the forementioned designation.
The engine of the ZZW30 was the brand-new all-aluminium 1ZZ-FE, a 1800cc straight-4. Like its predecessors, the engine uses dual overhead camshafts and 16 valves. The intake camshaft's timing is adjustable via the VVT-i system, which was introduced earlier on the 1998 SW20. Unlike its predecessors, however, the engine is now placed onto the car the other way round, making the exhaust manifold point towards the rear of the car. The 140 hp (104 kW) maximum power is quite a drop from the SW20 GT, but thanks to the lightness of the car it can move quite quickly, making the 0-100km/h dash in 7.5~7.9 s. In addition to the 5-speed manual transaxle, a sequential manual transmission controllable from the steering wheel was also available.
The feedback for the new model was somewhat mixed - others liked its return to AW11's design concept, while the fans of the SW20 would've liked it to continue along the path of the previous model. All agreed, however, that the ZZW30 had a nearly perfect handling, allowing one to brake into corners and throw the car through the corner in slight drift. ZZW30 is probably the best-handling MR2 model and for example Tiff Needell, a very experienced race driver and the former host of the BBC TV show Top Gear praised the handling of the ZZW30.
The MR-S was originally introduced in October of 1999 and received a sequential manual gearbox in August of 2000. For model year 2003, ZZW30 received some exterior changes, including a new front bumper, front and rear lights, and a new rear grille. The air intakes on the sides of the car were color coded and the interior was modified with new seats and a gauge cluster. The rear wheels were increased to 16" while the front ones remained 15", and both transaxles received an additional speed. The suspension was uprated with new springs and shock absorbers and a brace was added to the bottom of the car to improve rigidity. For 2004, the body was strengthened, adding 10 kg to the vehicle's weight.
For two decades, the MR2 has been a delight to car enthusiasts around the world, offering an affordable way to experience the marvellous handling of a mid-engine sports car. While Toyota is cutting down its selection of sports cars and replacing them with less aggressive "sports packages" offered on their more sedate cars, the future of the MR2 is somewhat uncertain. Many hope that Toyota will continue MR2 production because the leap along the price-axis to the next alternatives (Lotus Elise and Exige, Honda NSX) is so large that many an enthusiast would have to settle for a front-engined car, should the MR2 be discontinued. There was speculation that the 2005 model could be a hybrid car.
In July 2004 Toyota announced MR2 would be discontinued in US at the end of the 2005 model year because of increasing competition and lack of sales.  The ZZW30 sold just 7,233 units in its debut year, falling to 6,254 (2001), 4,705 (2002), 2,934 (2003), and 2,621 (2004).
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