Cheating in emissions testing by the Volkswagen Group has been headline news recently and, as I write, the accusations have spread to petrol engines and even to Porsche!
The group, which owns Seat, Škoda, Bentley, Lamborghini and Bugatti, plus Ducati motorcycles and commercial vehicle manufacturers MAN, Scania, Neoplan and VW Commercial Vehicles, is probably too big for the scandal to bring it down, but sales have dropped significantly in many markets across the world.
But cheating is nothing new, and it has come in many guises. MG owners in the 1930s found that their cars were not as quick as those tested by The Autocar and The Motor among others. The factory had apparently tweaked the engines of the press test cars. That backfired on MG because enthusiastic owners were determined to match the performance described in the published road tests, resulting in many warranty claims from owners who had blown up their MG engines.
In 1961, The Autocar was able to attain 150 mph in the road test Jaguar E-type (registered 9600 HP, chassis number 885002, the second prototype coupé). Octane magazine recently attempted to duplicate that speed with a carefully restored to standard condition E-type. They managed 146 mph on a stretch of unrestricted German autobahn and the driver felt that 150 was possible given a little more space. However, on 1960s roads, it is unlikely that even the
nice new motorways (still unrestricted) would provide a long enough clear run for any proud owner to reach 150 mph safely. There was a strong suggestion that 9600 HP had been tweaked by the Jaguar factory, and it certainly wasn’t a normal production car, but Octane’s effort indicates that very little tweaking would have been necessary.
More recently, when I was assessing cars for the RAC of WA magazine Road Patrol in the 1980s and 1990s, I found that it was almost impossible to achieve fuel economy anywhere near the official figures from government approved testing. At one time, I found that the then current Toyota Camry V6, Holden Commodore and Ford Falcon returned very similar real world economy figures, in spite of the Toyota’s superior official figures and the Falcon being clearly third best officially. As all three cars were roughly the same weight, I came to the conclusion that hauling the same weight of metal through traffic needed the same amount of fuel. The differences between official figures could be put down to how well each manufacturer tuned engines and arranged gearing to suit the government approved test, which was conducted on a rolling road with computerised instructions to the operator. While the manufacturers wouldn’t see it as cheating, it does give prospective buyers exaggerated expectations.
On a similar line, how many of you know that the performance figures released by major manufacturers are actually created by computer simulation. If you had visions of jockey-sized test drivers destroying clutches, tyres and transmissions in the quest for the best possible acceleration times, forget them. It’s all done by computer.
Most new cars have at least six forward gears, the latest BMW even has an 8-speed automatic transmission. Why so many gears when for decades motorists made do with only three speeds or four in sporty models? You will find that the higher ratios are too tall for anything but highway cruising on flat roads. The multi-speed automatics are probably designed to keep the engine in its most economical rev range during government specified tests for fuel economy and low emissions.
Cars with manual transmissions tend to have indicators on the dash telling the driver to shift to a higher gear. If the car also has a trip computer, it is interesting to set the display to instantaneous fuel economy. Watch what happens on an uphill stretch of road if you follow the instruction to shift up. You will often find the the fuel economy is poorer in the higher gear. I have performed this exercise in two cars, one a Ford Falcon GT with a 5-litre V8 engine that was more economical in 4th gear than in 5th when climbing the hills behind Perth, Western Australia. The second was a Ford Focus on the motorway between Perth Scotland and Edinburgh with a relatively tiny engine. Shifting up a gear in the Focus as instructed by the dashboard indicator resulted in an immediate reduction in the miles per gallon. While the V8 pulled strongly in either gear, the Focus was labouring in the higher gear.
Others have reached similar conclusions. In his test report on the new Mazda MX-5 in the September 2015 issue of Motor Sport, Andrew Frankel said: “The only reason a car with a top speed of 127 mph will do 85 mph with half its gears still to go is to try to fool the official test from which fuel consumption and CO2 figures are deduced. They have nothing to do with real world consumption and even less with driving.”