Road car news

Diesels set to disappear?

New tests could change face of European motoring | By Andrew Frankel

The long-predicted death of diesel as a fuel for production cars appears to have been hastened by the Volkswagen emissions scandal, according to a report published by Reuters. One year on from ‘dieselgate’, Renault – one of Europe’s major investors in the fuel – ‘now expects diesel to disappear from most of its European cars’.

The move follows comments made this summer by VW chief executive Matthias Müller, who said his company would have to see “whether it still makes sense to invest a lot of money in further developing diesel”.

The death of diesel will likely be hastened by new emissions procedures, due for introduction in 2019, based on so called ‘real-world’ testing, rather than widely derided laboratory-based tests conducted at present. The exact nature of these tests is not yet known, but they are likely to highlight the fact that NOx emissions of diesel engines are many times higher in normal driving than in closely controlled laboratory conditions. NOx is known to be a major cause of respiratory disease and has been linked to hundreds of thousands of deaths around the world.

Manufacturers now fear that the vast cost of engineering clean diesels will far outstrip the returns they are likely to make, so they’re beginning to refocus their efforts on petrol-electric hybrids and pure electric vehicles. This issue is compounded by the fact that petrol-engined cars are sold in vast numbers around the world, but their diesel equivalents are virtually unknown in the large markets of North America, China and Japan and now seem less likely than ever to gain local footholds. Bizarre though it may seem in Europe where, despite falling sales, more than half the cars sold continue to be powered by diesel, in the global passenger car market the fuel is actually something
of a niche product.

Simply deleting diesels from their ranges is likely to create as many problems for manufacturers as it solves. On average diesels produce a fifth less CO2 than petrol engines. Were petrol simply to replace diesel, manufacturers selling cars in Europe would be unlikely to meet the existing CO2 targets. The answer appears therefore to lie in hybrid power, at least in the short and medium term and until electric cars gain the range and charging times to suit the lifestyles of mainstream car buyers. 

Many still question the true efficiency and cleanliness of hybrid powertrains, citing the variance between claimed and real-world fuel consumption. With the extra weight penalty of hybrid systems, the inefficiency of carrying two powertrains when often only one or the other is active, and ongoing questions surrounding the true environmental impact of manufacturing and disposing of batteries, the case for hybrids is far from proven and their performance in the new testing regime simply unknown. But it seems probable that the reduction in NOx emissions that would undoubtedly result from the death of diesel would come only at the cost of increased CO2 emissions. The question governments need to ask is whether that is a price worth paying.

Ariel studies aero options

Remember the Chaparral 2J and Brabham BT46B sucker cars? Ariel does. The innovative low-volume British sports car manufacturer has unveiled its own concept (below), based on its successful Atom design and featuring fan-assisted underbody aerodynamics.

The so-called Atom Aero-P (Aerodynamic Efficiency & Optimisation Project) uses two small, battery-operated high-speed fans to suck air from under the car, the system being sealed by rubber skirts. The idea is to produce downforce from rest, rather than merely at high speeds as would a conventional wing, but also to reduce drag by removing the need for said wings, thereby improving performance, fuel consumption and emissions. Ariel boss Simon Saunders says the system is already providing more than three times the downforce seen using aerofoils, but that the project is at an early stage and much progress is still required.

The advantage of providing downforce across all speed ranges is clear. Cars like the Atom are finding their performance potential limited not by power but traction, an area in which current aerodynamic thinking has little to contribute. But there are challenges: the more downforce a car generates, the stiffer its springs must be to support its body weight, which might be fine on a racing car but presents obstacles in the road-car arena.

Also, the skirt system must provide a reliable seal in all conditions if downforce levels are not to vary mid-corner to the detriment of handling – and this is easier to achieve on a smooth track than a bumpy road.

But the potential is there: the BT46B won the only Grand Prix it contested – Sweden in 1978 – before being withdrawn by then-Brabham boss Bernie Ecclestone (the authorities hadn’t at that stage had the chance to ban it). Back in 1998 its designer Gordon Murray told Motor Sport, “Getting rid of it was the right thing to do. The BT47 I had on the drawing board would have pulled the driver’s head off…”

Original Cobra reborn

AC Cars is to produce a run
of nine brand-new Cobras to the exact specification of the first car, built back in 1962. The cars will be assembled at AC’s Brooklands premises and will feature the same 4.2-litre Ford V8 engine as early Cobras, rather than the far more common 4.7 with which the cars are most associated.

All cars will be left-hand drive and will be priced above £500,000.

The new Cobras might well prove popular among wealthy historic racers. Most Cobras are ineligible for the prestigious Pre-63 GT series and, indeed, the recently inaugurated Kinrara Trophy at Goodwood. Moreover, FIA Appendix K regulations state only that cars must be built to original specification to take part in its events, they do not need to be original themselves. Finally, while the earlier engine may be smaller, it revs higher and ultimately yields only a little less power than the 4.7-litre motor.

More power for Audi TT

Audi has unveiled the most potent TT yet, the 394bhp TT RS. Featuring an engine based on the five-cylinder motor seen in the current RS3, but with an aluminium crankcase that reduces weight by 25kg and increases power by 32bhp, the 2.5-litre TT now develops almost twice as much power as the original 2.1-litre 200bhp Audi Quattro managed with Audi’s first five-cylinder turbo back in 1980.

Audi claims a 0-62mph time of just 3.7sec for the TT RS coupé, and 3.9sec for the convertible.

The company has boldly priced the TT RS coupé at £51,800, making it more expensive than the Porsche 718 Cayman S that’s likely to be considered its most able rival. Audi will be able to point to the fact that its five-cylinder engine not only produces more power from the same capacity than Porsche manages with four, but also that its engine is likely to sound substantially better. The TT is faster on paper, too, the Cayman needing 4.2sec to hit 62mph even using launch control, though that is likely to speak more of the TT’s all-drive traction than a real performance advantage. Matching the Porsche’s handling prowess is likely to be a somewhat greater challenge.