October 2014 | Page 32

by Frank Beeton auto alert A probing review of significant global motor industry news Are Rear Engines Coming Back? Back in the 1950’s and 60’s, rearengined cars were commonplace. The trend was given tremendous early impetus by the huge success of Volkswagen’s original Beetle, and supported by rear-engined models from the likes of Renault, Simca, Fiat, Porsche, Hillman, BMW and even Chevrolet, with its highly controversial Corvair. The latter controversy centred mainly on the car’s roadholding (remember Ralph Nader?), and there was a body of opinion that rear-engined cars, in general, were prone to oversteer and frontwheel brake lockup on slippery surfaces. The main benefits of the rear-engine layout were the lack of transmission intrusion into the passenger space in compact cars, and good traction in slippery conditions with the engine and transmission masses concentrated around the rear driving axle. This configuration did have many enthusiastic protagonists who argued long and passionately about its benefits, but eventually, opinion and fashion swung in favour of the transverse-engined frontwheel-drive layout still common today. Finally, even Volkswagen capitulated, and, after first testing the water with the Passat one year earlier, the Golf went the FWD route in 1974. Since then, rear-engined cars have been quite rare. In recent times, there have been a few examples, such as the Smart Fortwo and Tata Nano, both of which were at the extreme lower end of the size spectrum. However, the recent emergence of a new class of “City Cars” in Europe, intended primarily for urban usage, seems to have opened up a fresh opportunity for rear-engined designs. Renault introduced its first Twingo city car in 1993 with a conventional front engine, front drive layout, and followed up with a second generation, using the Although appearing as a twodoor design, the latest Twingo does, in fact, have five doors, with concealed rear door handles. Other features include a comprehensive in-car entertainment and communication system, LED daytime running lights, electric power steering, electric front windows, remote central locking, speed limiter, trip computer, and automatic rear wiper activation. Safety features include Electronic ➲ Renault’s latest Twingo urban car – with its engine Stability Control, Hill Start Assist, at the rear Emergency Brake Assist, four airbags and tyre pressure monitoring. same driveline configuration, in 2007. In August, 2014, however, the third generation Undoubtedly, modern electronic Twingo made its appearance, with engine management interventions and lightweight, located at the rear. The advantages of this small displacement engines will have layout, according to Renault, are a shorter helped to cancel out the perceived historic overall length, and increased parking and disadvantages of rear-engined cars, and it traffic agility. The Twingo’s transverse is notable that the Twingo’s rear-engined engine has been tilted at an angle of 49° platform will be shared by the next iteration to reduce intrusion into the rear luggage of Smart’s Forfour model, in terms of compartment, and the application of Daimler’s expanding co-operation with Electronic Stability Control has eliminated Renault-Nissan. The fact that these two any concerns that the historic oversteering major manufacturers have adopted this tendency of rear-engined cars might have configuration will not go unnoticed by the persisted. The front wheels, unencumbered buying public, or their competitors, and by drive shafts or universal joints, have a if the claimed advantages are proven, cut angle of 45°, enabling a best-in-class there could be a serious rethink of design turning circle of 8,59 metres. The overall philosophies higher up the size scale. package is shorter than its predecessor Historically, rear engines were, with the by 10 cm, but has more room for its four exception of the six-cylinder Corvair, to be occupants. found in smaller cars, but in the modern The new Twingo’s rear seats can be set in an upright position to increase luggage accommodation, and the front passenger seat can be folded flat for more carrying capability. Power for most models is provided by a 3-cylinder, naturallyaspirated, one litre, 12-valve SCe 70 engine developing 70 hp, but the Dynamique TCe 90 version is equipped with 0,9 litre turbocharged unit developing 90 hp. Front suspension is by MacPherson struts, while there is a De Dion torsion beam axle at the rear. | words in action 30 scenario, there is no good reason why this should be the case, and designers of larger vehicles may also be tempted into exploring the benefits in considerably larger packages. We will be watching future developments with interest. Audi Goes for 48 Volts Audi has revealed plans to upgrade part of its vehicle electrical systems from twelve to 48 volts. october 2014