Sunday, 13 January 2013
Road testers are sensitive souls. Driving the new Golf I was struck with how refined it was. The 1.4 petrol engine was next to inaudible, wind noise subdued, the new MQB platform, I decided, superbly engineered and of a quality to match VW’s reputation. It was only when I got into a 2 litre diesel - same morning, same roads, but almost at once it went b-r-r-r-r-p. The body drummed. On smooth bits of road it went Ph-o-o-o-o-h but on every patch and joint it thrummed and strummed. It rocked a bit on potholes and tilted on cambers. Tyres, I decided. Why do they put press test cars on low-profiles? Maybe the Golf is quite ordinary after all.
I was being pernickety. Princesses and peas come to mind. Besides the 7J rims and 225/45 R17 tyres, the 2 litre had sports suspension, lowering it by 10mm. The 1.4 on the other hand had perfectly sensible 6½J rims and 205/55 R16 tyres, making it is a model of a modern middle-sized saloon, well balanced and exemplary. No wonder it is Europe’s best seller. At £19,645 my money would be on the petrol 1.4, not the £24,880 diesel, despite being short of some 28PS. There is scant difference in performance (0.7sec to 62mph), none in CO2 emissions and you would be only 9mpg better off. It would need to do a lot of miles to make up £5235.
This is the diesel with the silly tyres.
The Golf has been restyled but not too much. It still looks a bit anonymous but a lot of buyers like that. They don’t want to make a statement. They are conservative, content for neighbours not to notice a new car. Best way to assess a car – assess the buyers.
VW has been clever about weight. Ever since I can remember new cars have put on middle aged spread. Customers always go for de luxe versions, so “improvements” never stop. Legislation and safety features always add bulk and throughout 38 years, 29million cars, and seven generations the Golf grew from 370cm (146in) long and 750kg (1650lb), to 450cm (177in) and 1140kg (2508lb).
At 425cm (167in) the new one is 5.6cm longer than the last (sixth) Golf but VW has saved 100kg (220lb), which brings it back to about the weight of the fourth or fifth generation. The wheelbase has been stretched and the body widened, so there is more room inside, the hatchback is bigger and there is more luggage space. It’s clever the way weight has been reduced; the structure is 37kg lighter, engines 40kg, running gear 26kg and even the electrical system weighs 6kg less. Aluminium engine blocks make a big saving.
Materials are used sparingly. Sheet metal thickness varies within one item. The rolling mill of the steel supplier makes what they call a tailor rolled blank, a sheet strip with variable thicknesses. Delivered to the hot-forming factory it has 11 areas each of a different thickness, with transitions between them so uniform there are no abrupt changes in strength. The saving is just 4 kg in one cross-member. Simples! As Sergei would say.
If cars of the Twenty-first Century are as good as the Volkswagen Golf with the Umwelt Diesel, giving up petrol engines will not be so bad. This is no sprinter, but it is lively enough and like policemen did in less frenzied times, proceeds in a measured way, which is faster than it looks.
The significance of the Umwelt (for Environmental) diesel engine is that it is the world's cleanest liquid-fuel combustion engine. Cleaner than any petrol engine the exhaust does not even have the characteristic diesel smell. VW has equipped it with a turbocharger, not so much to gain power, as pump 40 per cent more air in to make the combustion process more complete.
The result halves particulates to bring them well within strict American standards, and also banishes the discharge of highly suspect polycyclic aromatic hydrocarbons by means of a simple oxidation catalyst.
The engine still has some strong diesel mannerisms. There remains a few seconds' pause between turning the key and starting up. The seat belt can be put on in the time it takes for the pre-heater indicator light to go out. And when the engine does start, it is accompanied by the orthodox diesel-taxi clatter, although not for long. Once under way, the noise is inaudible from inside the car and not obtrusive from outside.
The engine also has a low rev limit. Around 4,500 rpm on the tachometer - if this model had one - the power tails off and the car will accelerate no more. Diesel engines need a heavy flywheel to turn them over from one high-compression stroke to the next, so they do not spin quickly up to speed.
Racing engines are given a light flywheel to achieve the opposite effect - to run up to maximum revs almost the instant the throttle is opened. The corollary is that racing engines tend to be harsh and vibrant, while the Umwelt is smooth and constant, achieving its useful turn of speed with a cultured hum.
VW does not even put a D label on the back of the Umwelt Golf, to distinguish it perhaps from the smoky smelly diesels of old. However like former diesels, it still does not exactly dash up gradients, but reaches 100mph, and cruises serenely for a price of £9,739.93. It is a plain five-door Golf with no frills, not even central locking or electric windows. It is almost an industry cliché that diesel engines are installed in basic models on the grounds, it would seem, that diesel drivers are so consumed with ideas of economy that they are unlikely to pay for frills, even cheap ones.
VW's motives in producing the Umwelt may not have been entirely altruistic. Diesel sales in Germany over the past two years have dropped by a third, but the new cleaner engines being produced by VW and Daimler-Benz can be expected to reverse the trend in Germany, and increase the demand in Europe as a whole, the world's main market for diesel-engined cars.