Vehicle Comparisons

Audi A8

Audi A8

This MK4 model Audi A8 faces some tough rivals, but there's an argument that it's as good as any of its competitors, even Mercedes' mighty S-Class. It's smarter, larger and more sophisticated and claims to be the first production car in the world to have been developed for highly automated driving.

The array of engines you get in the latest A8 is pretty mouth-watering. While it's true that the oily bits have been tweaked rather than offering anything overwhelmingly novel, they were good to begin with and have just got better. There are two extensively re-engineered V6 turbo engines: a 3.0 TDI and a 3.0 TFSI. The diesel develops 286PS, and the petrol version 340PS. There's also an eight-cylinder TDI - a 4.0-litre with 435PS - and as before, the exclusive top engine version is the W12 with a displacement of 6.0 litres. An e-tron quattro variant has also been developed, this derivative mating a 3.0 TFSI petrol engine with an electric motor to achieve a 449PS output and 700Nm of torque.

This time round, dynamic all-wheel steering complements the standard quattro permanent all-wheel drive system and buyers also get Audi AI active suspension, a fully active suspension set-up. Depending on the driver's wishes and the driving situation, it is capable of raising or lowering each wheel separately with electric actuators. This newfound latitude enables it to deliver the polished ride comfort of a classic luxury saloon and the taut, composed agility of a more driver-oriented performance car in equal measure. It's clever. It's an Audi. What else did you expect?

Audi says that this fourth generation A8 signals the beginning of a new design era for the entire brand. The front end with its wide, upright Singleframe grille and the fluid, muscular body both aim to convey power, elegance, sophistication and modernity. As before, two bodystyles are available, the 5.17-metre 'standard' version and the A8 L, which has a 13cm-longer wheelbase. Space is often considered to be the ultimate luxury, and compared to its predecessor this MK4 A8 has grown substantially in length in both body styles. Occupants can also now relax in even more sublime surroundings, with every detail radiating superlative bespoke quality - from the perforation in the seat upholstery to the electrically opening and closing shutters on the air vents.

The most sought-after seat in the new Audi flagship model could quite possibly be the rear left - the optional relaxation seat in the A8 L that comes with four different adjustment options and a footrest. In this seat, the passenger can warm and massage the soles of their feet on a unit with multiple settings incorporated into the back of the front-passenger seat. Up-front, the instrument panel is largely free of buttons and switches. At its centre is a 10.1-inch touchscreen display which, when off, blends almost invisibly into the high-gloss black surround thanks to its black-panel look.

This fourth generation A8 is an impressive achievement. Every car in this segment is. As it should be, this is a showcase for Audi's best and most advanced engineering, aluminium construction and quattro all-wheel-drive now joined by astonishingly clever industry-leading automated driving technologies. Add in classier design and a range of engines that are pokier yet cleaner and more frugal and you've a formidable luxury saloon.

But is it one that you can bond with, a luxury conveyance you'll love as well as admire? The answer depends upon the owner of course. Some may still see this A8 as being a little remote compared to a wood-panelled Jaguar, a status-conscious Mercedes or a proudly opulent BMW. I'm guessing though, that a significant number of boardroom buyers might now find this Audi a surprisingly complete all-round choice. Hugely capable, innovative and beautifully built, this is the car that rivals always feared Audi would build. And if you're in this market, it's one you need to try.

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Mercedes-Benz S-Class

Mercedes-Benz S-Class

Mercedes-Benz reckons that its S-Class saloon is very possibly the best car in the world and this revised version of the W222 model backs that claim up with some hugely impressive technology. It's enough to keep this car very competitive indeed against aspiring rivals.

This improved S-Class features more than 6000 fresh components and various new engines. The key news is that the 3.0-litre V6 diesel that's been used in volume versions of the S-class since 2005 has at last been replaced. Instead, customers are being offered a completely new 2.9-litre in-line six cylinder diesel motor developing 286bhp in the base S350d. This powerplant uses variable valve lift control for the first time and is mated to a new, even smoother 9-speed 9G-TRONIC auto gearbox. In the S350d, 62mph from rest takes just 6.0s en route to an artificially-limited maximum of 155mph and on the move, the electronically controlled air-sprung suspension delivers ride quality that rivals can't quite match. Its incorporated MAGIC BODY CONTROL' set-up now incorporates a further curve-tilting function that tilts the body by up to 2.65-degrees through the bends so that passengers will hardly notice it as you go through tighter turns.

Other engines on offer in the line-up are all petrol-powered. They include a 3.0-litre petrol V6 with 457bhp in the S500 variant that'll be a rare sight on our roads. The top Mercedes-AMG S 63 variant gets an AMG-developed 4.0-litre biturbo V8 petrol powerplant with 612bhp to replace the previous 5.5-litre V8. The top S 65 gets a twelve cylinder 6.0-litre 630bhp unit.

We may be talking about a facelift here, but it's the most extensive model rejuvenation of any that Mercedes has undertaken in its entire history. You wouldn't really know that from a glance at the exterior of this car. Its dimensions are unchanged, so it remains 5,125mm long in its standard form, or 5,255mm in length in its long wheelbase guise. Changes are limited to details things: the prominent chromed front grille has been updated, as have the bumpers and the graphics of the LED headlamps and tail lights.

Inside, the cabin materials are of an even higher grade than before, but otherwise, the spacious interior will be familiar to previous buyers of this sixth generation design. That means the front of the cabin continues to be dominated by two 12.3-inch screens and uses touch-sensitive steering wheel controls. New is an 'Energizing Comfort Control' package that links together various comfort systems in the vehicle: you choose a mode ('freshness', 'warmth', 'vitality', 'joy', 'comfort') and the set-up uses a range of various elements - interior climate, music, massaging seat settings, cabin fragrance and so on - to deliver a co-ordinated 10 minute programme aimed at re-vitalising you. On a more practical note, there's a 510-litre boot.

This S-Class spearheads technological development, not only for Mercedes-Benz but for the automotive industry as a whole - and has done for decades. It's that important and is why this is - and will continue to be - the world's best selling luxury car.

In this improved sixth generation form, it can power to supercar speeds in AMG guise, deliver nearly 100mpg in Plug-in Hybrid form and can be specified to eerily steer, power and brake itself at a cruise in whatever form you decide upon. Magic Body Control can even make bumps and potholes disappear, transforming the roadway into a magic carpet. No other car you could choose can do all of this, which is why this S-Class will remain a benchmark for the kind of luxury saloon every prestige brand would like to build and a reference point for the current state of automotive technology. The best car in the world? You'll feel like it is if you buy one.

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Tesla Model S

Tesla Model S

Here is an electric car with over 300 miles of range that can seat up to seven, has acceleration to demolish an Aston Martin and features zero tailpipe emissions. There's now a choice of either 75 or 100 kWh battery outputs and either way, you get standard 'Dual Motor All Wheel Drive'. At the top of the range, there's a flagship P100D flagship variant with super saloon-style performance. Here's what the future looks like - and it's cause for celebration.

What are the driving characteristics you'd look for in a big luxury car? We'd be looking for hushed refinement, a smooth step-off the line, instant acceleration as soon as you prod the throttle and the handling ability of a smaller car. The Tesla Model S delivers all of these things and more. The 2.2-tonne kerb weight hints at a rather portly demeanour but the Model S handles a good deal more sharply than you might imagine. The steering can be switched between three settings - Comfort, Normal and Sport - changing the weight of feel but not markedly adjusting the level of feedback. Ride quality is better than you'd expect from a vehicle running on 21-inch wheels. Air suspension is optional and worth having. As you'd expect from an EV, there's no gearbox as such, so power transfer is even smoother than the best automatic transmissions.

That power comes courtesy of batteries developed by Panasonic which sit under the floor of the car, keeping the centre of gravity low, while the electric motor sits atop the rear axle. In the mainstream range, customers choose between 75 kWh and 100 kWh variants. Even with the 75 kWh version, sixty is just 4.2s away from rest, so you'll be looking at very rapid progress. All derivatives get standard Dual Motor All Wheel Drive, which gives you get two electric motors, one sitting on the front axle, the other driving from the rear. With the power spread around the drivetrain, you've of course got the perfect recipe for AWD traction.

The same AWD set-up is used by the insane flagship 'P100D' variant. 'Insane' is a word we feel we have to use because it designates the most frantic of this top Tesla's three driving modes - the others being 'Normal' and 'Sport'. Go 'Insane' and 60mph is just 2.5s away from rest, courtesy of a 761bhp combined power output. As advertised, there's nothing else with four or five seats that can get remotely close to this kind of pace.

Tesla deliberately set out to style this car in a relatively conservative fashion so as not to alienate its core buyers. There's even a dummy air intake at the front. The car it most closely resembles in external dimension is a Porsche Panamera, but when you check the tape measure, you realise quite what a massive car this is. At 4978mm long, 1964mm wide and 1435mm high, it's 8mm longer, 33mm wider and 17mm taller than a Porsche Panamera, which is already a pretty sizeable hunk of automotive real estate. The width makes it feel a handful on narrow city streets but there's plenty of space inside.

The Tesla Model S is a remarkable vehicle. It changes the way you'll view the whole concept of a motor car. As long as you are willing to alter your long-held preconceptions of what an automobile demands and, in turn, delivers, the Model S demonstrates that the genuinely practical electric vehicle has been achieved. Caveats are few. Yes, battery charging does require a little more thought than just topping up a tank and if a car is shared between a married couple for instance, you'll both need to be on the ball with it.

Other than that, it's a tour de force. The interior is adventurous, the packaging ingenious, the styling sleek and mature in its execution. It's searingly rapid, wonderfully refined and rides and handles well. If this is the future of cars, bring it on. The internal combustion engine has had a good innings and certainly has charisma, but the Tesla Model S opens a window to a better way.

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