With petrol engines you can pretty much tell how they will perform, from relatively slow 1.6-litre engines to the high performance 3.0-litre models. But diesel technology has moved on so much in the past few years that size doesn’t have such a direct relationship to performance.
So while a 1.6-litre petrol engine might struggle in an upper-medium car, a 1.6-litre diesel is perfectly adequate, even in an estate such as Peugeot’s 407 SW.
The same is true in the executive car segment, where smaller engines are holding their own against the big boys.
Take the Audi A6, where the petrol engine range starts at 2.4 litres and goes up to 3.2 and 4.2-litres. There are also 3.0 and 2.7-litre diesels, but starting the range is the 2.0 TDI and it is much more than just a bargain-basement model.
Admittedly the engine offers just 138bhp, which may sound inadequate for a car weighing in at nearly 1.6 tonnes, but diesels make up for their lack of outright power with far more mid-range grunt than petrol engines.
Through its six-speed manual gearbox, the 2.0 TDI hits 62mph from rest in 10.3 seconds and goes on to reach 130mph – hardly sports car performance and more than a second slower than all the other models in the range, but its on-the-road performance is better than the figures suggest.
The engine revs quietly and strongly all the way to the red line, with little hint of vibration even though it is a four-cylinder unit. Like so many modern diesels, it just doesn’t feel like one.
Evidence of that extra mid-range comes when you want to overtake another car in third or fourth gear. It may take a second for the engine to respond to your input on the throttle, but once the turbocharger has spooled up it delivers a surge of power which makes dispensing with slower-moving traffic a doddle.
And with a light, smooth gearchange, it can happily keep pace with the 2.4-litre petrol model.
The only downside is the ride – very hard on our test car’s optional 18-inch alloys (a whopping £1,950 extra) and still firm on the standard 17-inch rims, and the steering, which is so over-assisted that it offers virtually no feedback.
Thankfully there are plenty of toys to keep your mind off the ride and steering.
Standard equipment is far from sparse on this entry-level model, and includes cruise control, CD player, electric front and rear windows, climate control and rain sensing wipers.
So what you have is an executive car which is at the bottom end of the engine line-up, with weaker headline performance figures, but otherwise it stands shoulder-to-shoulder with the other offerings in the range.
Delivered price, standard car (P11D value): £24,337
CO2 emissions (g/km): 169
BIK % of P11D in 2005: 20%
Graduated VED rate: £135
Insurance group: 14
Combined mpg: 44.8
CAP Monitor residual value: £9,750/40%
Depreciation 24.31 pence per mile x 60,000: £14,586
Maintenance 3.08 pence per mile x 60,000: £1,848
Fuel 9.58 pence per mile x 60,000: £5,748
Wholelife cost 36.97 pence per mile x 60,000: £22,182
Typical contract hire rate: £484
At a glance
We don’t like
Three rivals to consider
WE’VE taken entry-level diesel models from the big four premium manufacturers to compare, and it’s the Audi which is the cheapest at the front end. The A6 undercuts the new BMW by £1,400, giving it an early advantage when it comes to working out company car tax bills. Both are well ahead of the Jaguar and Mercedes-Benz – the Audi is £3,400 cheaper than the S-type diesel (which comes with a much more powerful engine) and £4,000 less than the E220 CDI.
THE Audi has a clear advantage in service, maintenenace and repair cost terms, with a likely bill of £1,848 over three years/60,000 miles. None of the other three manage to dip below the £2,000 barrier, with the Jaguar leading the way among the runners-up with a bill of £2,250. The BMW runs the S-type close though, with a bill of £2,520 – just £54 ahead of the fourth-placed Mercedes-Benz. Obviously these cost predictions will vary depending on how your drivers look after their cars.
BMW’s 520d is the best for economy, returning a claimed average of 47.9mpg. If drivers can match this figure, then fleets can expect a fuel bill of £5,376 over three years/60,000 miles. Second spot goes to the Audi, which returns 44.8mpg for a bill of £5,748. The E-class is just behind on 42.8mpg for a cost of £5,910. The Jaguar fares the worst, returning 41.5mpg, although it is worth remembering that the S-type’s 2.7-litre twin-turbo V6 produces 206bhp, eclipsing the Audi’s 138bhp, the BMW’s 163bhp and the E220’s 147bhp.
THE Jaguar faces a double whammy, with the highest front-end price and the lowest residual value prediction. CAP estimates the S-type will retain 33% of its cost new after three years/60,000 miles, well behind the standard set by the others. The A6 retains 40%, and thanks to its low front-end price it is the least affected by depreciation. The E-class retains 41%, but its high price counts against it. The 520d has the best RV forecast of 43%, but it costs more to buy than the Audi.
Audi’s A6 is the cheapest car for a fleet to run over three years/60,000 miles, just dipping below the 37 pence per mile mark. Its nearest challenge comes from the new BMW 520d on 37.74ppm – it competes well with the A6 in all areas except front-end price. The Mercedes-Benz and Jaguar are off the pace, both costing well in excess of 40ppm. Similarly, their challenge is also blunted by a high purchase price.
Emissions and BIK tax rates
THE BMW offers drivers the route to the lowest company car tax bills. A 40% taxpayer will have to find £154 a month to have the 520d on their drive – £8 a month less than the Audi A6. Although the E220 CDI performs well in CO2 emissions, its higher price counts against it, leaving the same taxpayer with a £179 bill per month. The Jaguar has by far the highest emissions and P11d price, and by far the highest power output, resulting in a monthly benefit-in-kind charge of £222.
THERE’S a simple choice to make here and it boils down to two cars. The Audi A6 and BMW 520d both have a desirable badge on their bonnet and are stylish, well-built and well-equipped. The A6 will be slightly cheaper for a fleet to run over three years and 60,000 miles, but the 520d is easily the better car to drive – it feels much more like a sports saloon than the slightly stodgy Audi. The BMW also offers drivers lower company car tax bills.