Currently reading: 90 years of the Autocar road test: Design and engineering
The mechanical evolution of the automobile, as seen through our testers’ eyes over the years
4 mins read
22 October 2018

The four-valve cylinder head was seen as a powerful marketing tool in the 1980s, when a ‘16v’ badge on the back of a Mk2 Volkswagen Golf GTI added sexiness to the car.

Yet multi-valve heads were old hat by the time Autocar started testing cars in 1928. The Stutz Bearcat used a multi-valve head in 1916 and both Bentley and Bugatti had four-valve heads.

Fuel injection is another technology that gained glamour status at the hands of marketeers in the 1980s, but it had been around for decades. Like many advances, fuel injection was pioneered in aviation, where mixture control is more complicated due to extreme altitude changes. The first petrol injection system appeared on a Léon Levavasseur-designed aero engine – the first V8, no less – in 1902. Bit of an unsung hero, Monsieur Levavasseur.

The Mercedes-Benz 300SL (road test 1560) is often credited with being the car that introduced fuel injection to the public highway, but the two-stroke Goliath GP700 that arrived in 1952 got there three years earlier using a system developed by Bosch.

Nothing quickened the pulse of the 1980s road tester more dramatically than a dose of forced induction, more specifically turbocharging. But the use of engine-driven superchargers goes back to the beginning of the internal combustion engine’s life in the 1880s. Our 1928 road testers got their first taste of supercharged horsepower with the Mercedes-Benz Model K, which used a blown 6.3-litre straight six making 160bhp.

Turbochargers are almost ubiquitous today but the technology took longer to take off – and an aviation analogy is apt, because turbochargers were first used on aero engines in the 1930s. The development of turbochargers carried on through World War II, with the first appearing on a production car on the Oldsmobile Cutlass Jetfire in 1962, although Europe had to wait until 1973 for BMW’s 2002 Turbo.

Cool as it was, the 2002 didn’t quite have the impact on the schoolboy senses as Porsche’s 911 Turbo, which was launched a year later at the Paris show. The words ‘Porsche’ and ‘Turbo’ pretty much defined high- performance motoring in the 1970s.

What about diesels? Our forebears would have found their first production diesel car at the 1933 Paris show. Citroën was displaying its charmingly named Rosalie, which was available with an optional 1.7-litre diesel engine. Then in 1936 Mercedes launched a diesel saloon, called the 260D.


Find an Autocar review

Back to top

There’s a case for saying that of all automotive developments, it’s the diesel engine that took longest to perfect. I’ve never driven a 260D but I suspect it was a bit of an old rattler, and early 1980s diesels were certainly harsh on the ears and joints. Things looked up in 1978 when Mercedes launched the turbocharged 300SD, and Peugeot followed the year after with the 604. Unfortunately, and as has so often been the case, us Brits were fiddling with the technology far earlier but failed to get it into production. Rover had been experimenting with intercooled turbodiesels as early as 1963.

A far more exotic Rover project was its jet turbine programme. The most famous car, ogled at by generations in London’s Science Museum, was the JET1. This convertible concept was built in 1949/50 and looks like it could just about crack 70mph but actually managed more than 150mph. Chrysler got nearest to productionising a gas turbine road car with its 1963 Turbine, but in the end only 50 were built.

Chrysler and Rover aren’t the only firms to work slavishly at powerplant concepts others have shied away from. At the 1964 Frankfurt show, NSU unveiled the Wankel Spider (road test 2043), the first production car to use a rotary engine. NSU went on to make the stunning RO80 which, when it went out of production in 1977, was the last car to wear the marque’s badge. Mazda produced its rotary-engined Cosmo 110S in 1967 and went on to iron out most of the Wankel’s inherent problems, in particular sealing of the rotor tips.

Back to top

The RX-8 was Mazda’s last rotary-engined car, but there are persistent rumours that we haven’t seen the end of this intriguing powerplant.

In 1988, I set out to test a Lancia Integrale and Toyota Celica GT-Four. In my pocket was a pamphlet, given by Toyota, telling me where to find the small number of petrol stations that stocked unleaded. The GT-Four was the first car to go on sale in the UK that required it, and in 1988 only 11% of filling stations sold it.

Throughout the 90 years of Autocar road tests, our testers have seen many technologies arrive and then disappear. Ford fitting a starter motor to the Model T in 1919 pretty much put paid to the electric car because no longer did you risk snapping your thumbs when hand- starting an engine. Yet today the electric car is now a regular subject for our testers’ critical eyes. Other technologies we’ve sampled over the past few decades as concepts are now joining the mainstream – hydrogen fuel cell cars, for example. And who’d have thought that our test of the first Toyota Prius back in 1997 would be the start of something so big?

Read more

Volkswagen Golf GTI review

Porsche 911 Turbo review

Paris motor show 2018: full report

Join the debate

Add a comment…
jason_recliner 22 October 2018

A few other big changes

Materials. Steel still dominates, but wood has all but disappeared. Aluminium and magnesium is used where appropriate and affordable. Carbon fibre is becoming more common.

Construction. Separate chassis is limited to off road and commercial vehicles now.

Computers have more or less completely replaced mechanical control.

Find an Autocar car review