After the S-Class had been on sale in the UK for six years, Mercedes offered an impressively wide range of engines.
The V6 petrol engine is good for 302bhp and can take this big car from 0-62mph in just 6.9secs. The addition of Mercedes’ BlueEfficiency technology, meant it promised an official combined fuel economy figure of 37.2mpg, impressive for its day.
The S 500 has a 4.6-litre V8 and 429bhp and still offered 30mpg, but the S600 and the two AMG models are exceptionally rapid.
However, it’s the S 350 CDI, which at the time was the UK’s most popular S-Class model, scooping up more than 80 percent of sales.
Changes to the previous-generation 3.0-litre common-rail diesel engine included improved injection efficiency, added turbocharger boost pressure and reduced compression ratio – boosting power by 22bhp at 254bhp. Torque rose by 59lb ft to 457lb ft, developed at 1600rpm, as before.
The upshot is added off-the-line performance, even more impressive mid-range shove, relaxed cruising attributes and a level of mechanical refinement that encroaches on that of then petrol S-Class models.
Mercedes also fitted its latest urea injection system. Concentrated within the catalytic converter, it turns up to 80 percent of nitrogen oxides expelled by the engine into harmless nitrogen and water. A 25.7-litre tank for the urea solution is mounted in the spare wheel well and needs re-filling every 15,500 miles.
With the help of the seven-speed automatic gearbox and stop-start, the S350 Bluetec should achieve a combined 41.5mpg and a CO2 rating of 177g/km.
Some drivers might have regretted that the 2011 four-cylinder diesel S-Class was never offered in the UK. The 2.1-litre diesel engine managed 201bhp and a sturdy 368lb ft of torque; it gave away 53bhp and 89lb ft to the 3.0-litre V6 diesel-powered S 350 CDI.
The relatively small engine does a commendable job of hauling the S 250 CDI’s considerable 1895kg. Theoretically it’s capable of travelling up to 900 miles between refills on its 83-litre tank. When we tested it on the autobahn, it managed a remarkable 55mpg over 200 miles, proving that it can live up to its maker’s claim.