The BMW 5-series has been the long-running leader in the executive sector, but has come under sustained – and many argue successful – attack from the new Mercedes-Benz E-class. But the S-class regularly seems to sweep all before it in a category where the difference between first and nowhere are often degrees of perfection.
And Mercedes-Benz raised the bar again by revamping the S-class last summer with discrete new lustre to the headlights, a new tail light design and a more prominent grille (how much more prominent can you be driving an S-class?).
Inside, virtually all areas of the car are as excellent as you would expect. The interior, particularly the fascia, has been tidied up and many of the buttons strewn across the face of the old model have been re-engineered into tidier groups. Where I start to screw my face in consternation though, is the engine, but not through any doubts of its ability.
The 3.7-litre unit in the S350 is more than half-a-litre bigger in total volume than the one it replaces. It churns out a healthy 245bhp and 258lb-ft of torque in the mid-range, which is more performance than you would ever really need in a car as big and relaxed as this, as it will do 0-62mph in 7.6 seconds and a top speed of 153mph. It sounds great under hard acceleration, shrinks away to nothing when cruising and is as smooth as Pierce Brosnan in the mood for romance with a gearbox that changes ratios with delicate subtlety.
The steering is light at slow speeds and makes this car surprisingly easy to wield around a car parking space.
It has CO2 emissions of 266g/km and does 25.4 mpg. But why have it? The problem is the S350 is no more remarkable than the already remarkable S320CDI. If the owner will only consider petrol, then only when the engines get seriously legendary like the V8 500 or the insane bi-turbo V12 600 does the petrol route score a convincing win over the diesel.
The S320CDI emits only 204g/km of CO2, which for a car of its weight and engine displacement is quite a feat, and puts it in the 27% benefit-in-kind band this year, while the 350 languishes in the 35% band.
As a result, a 40% tax-payer will pay nearly £1,800 a more for the S350. And the diesel does 36.7mpg on the combined cycle. But despite the fact that the S350 has its thunder stolen by another model in its own range, it is still a fine car. Get it rolling and long journeys are a stroll. In fact they are an interesting social experiment. Drive an S350 down a motorway and the traffic will dive aside in deference, metaphorically doffing caps as you go.
Who says the class culture is dead?
My only small concern – and it's not the first time on a Mercedes-Benz – would be the hydraulic brakes, which are essentially brake-by-wire.
Very clever, no doubt, as there is no mechanical linkage between pedal and wheels, and extremely powerful, but they have very little feel and tend to bite suddenly, particularly at low speeds.
At motorway speeds they feel much more progressive, in keeping with the S350's ability to travel fast effortlessly.
Approach a high speed motorway bend with velocity and the large mass settles over its AirMATIC suspension and huge wheels and corners imperiously. It all adds up to a wonderful all-round luxury package.
Delivered price, standard car (P11D value): £46,630
CO2 emissions (g/km): 266
BIK % of P11D in 2003/04: 35%
Graduated VED rate: £155
Insurance group: 18
Combined mpg: 25.4
CAP Monitor residual value: £19,850/40%
Depreciation (48.81 pence per mile x 60,000): £29,286
Maintenance (5.16 pence per mile x 60,000): £3,096
Fuel (14.97 pence per mile x 60,000): £8,982
Wholelife cost (68.94 pence per mile x 60,000): £41,364
Typical contract hire rate: £1,010.85 per month
Three rivals to consider
This really is a battle of the big boys, and all the cars here have P11d values to match their huge dimensions. The S350 – oddly for a Mercedes-Benz – is the cheapest, followed closely by the Range Rover, which has the most individual interior and the biggest engine. The 735i comes packed with all of BMW's i-Drive goodies but requires a read of the handbook before starting. The A8 is the most understated and has a similar, but simpler, version of BMW's i-Drive.
Range Rover £49,815
By virtue of its £500 Concours package which covers labour, service and maintenance costs for five-years/75,000-miles, the BMW does fantastically well in this section, beating the S350 convincingly. Audi also offers an identical package on the A8, helping it to second place on 4.70ppm. The Range Rover is also cheaper, at 4.25ppm, which equates to costs over three-years/60,000-miles of more than £2,500.
Range Rover 5.12ppm
Predictably the Range Rover, with its huge weight and brick-like aerodynamics, cannot get anywhere near the other cars on fuel costs, but to get anywhere close to the others in performance, it needs the BMW-sourced 4.4-litre V8. There's not much in it between the others, although the A8's quattro four-wheel drive system blunts its economy challenge. The BMW and the Mercedes-Benz fight it out at the top, but driving along at 14 pence per mile is an expensive business.
Range Rover 21.94ppm
In terms of residual value the Mercedes-Benz, despite being the longest in the tooth and barring the recent raft of minor tweaks, still manages to be the best here in depreciation, closely followed by the Range Rover, which proves the value of a niche product in any sector. The A8 lags behind – it is almost 6ppm more than the S350. The BMW wobbles in comparison because praise for it is not universal – the controversial styling and doubts over the i-Drive control system outweigh the car's dynamic qualities.
Range Rover 49.15ppm
A well-rounded combination of talents puts the S350 top in wholelife costs, although it is still a mind-bending £40,000-plus after three-years/60,000-miles. The 735i is close behind and more conservative styling might have shored up the residuals and resulted in a closer finish.
The Audi comes third, neither excelling in any area nor doing particularly badly – although it runs the BMW close for second place. The Range Rover suffers because of heavy fuel costs.
Range Rover 76.21ppm
Emissions and BIK tax rates
As usual, the CO2 offerings mirror the fuel costs, and in this sector the amount of CO2 emitted is way above the highest benefit-in-kind tax band for most of these cars for 2003/04. Expect to pay more than £6,500 in tax a year for the privilege of driving these cars. For those with environmental sensitivities, the Range Rover is almost off the scale. However, at this level costs are not really that high on the agenda.
Range Rover 389g/km/35%
There can only be one winner – the Mercedes-Benz S350. It is consummate in every area – image, looks, build and reliability. The BMW 735i is a delight to drive and will please some, but not all, with its complicated styling and electronics, while the Audi A8 is handsome and clever but still doesn't have the cache of the Mercedes-Benz. And for those needing flexibility the Range Rover is as capable off-road as it is on.