EVERY so often cars come along that manage to redefine an entire brand.

Audi's TT is a case in point and so too is the Bentley Continental.

This sporting and sumptuous grand tourer is a car that really brought Bentley kicking and screaming into the 21 century and its runaway success helped spur the Crewe car maker on to new heights.

The second generation Continental isn't all that different to the car that got the ball rolling, probably because Bentley decided not to mess around too much with a winning formula.

Looks-wise it is certainly sleeker and sharper than its predecessor, though the enhancements are subtle rather than severe, while under the skin some mechanical modifications have made it an even better performer than before.

One of the other big changes, as far as the range is concerned, is that there's now a leaner and greener version.

Yes, even Bentley it would seem are committed to delivering greater fuel efficiency and getting emissions down.

But before you get carried away and imagine Bentley have produced some super-frugal hybrid (though I'm sure they will some day) this 4.0-litre V8 is hardly in the olive branch to an environmentalist league.

Nonetheless it represents a pretty radical departure for a manufacturer traditionally associated with engines that were essentially larger and more powerful than pretty much everyone else's.

It's about £12,000 cheaper than the more traditional and arguably Bentley-esque version of the Continental - a whopping 6.0-litre W12 - but anyone who imagines it might be lacking is in for a surprise.

This V8 engine is a clever Audi creation, that's been modified and finished by Bentley, which in essence utilises either four or eight cylinders as it sees fit.

As well as there being a £12,000 price differential compared to the W12, buyers can benefit from a fuel economy improvement of almost 10mpg on the combined cycle.

Compared to an average family motor a car that returns 26.7mpg might not sound great but when that car is a Bentley it's difficult not to be impressed.

In performance terms there is surprisingly little separating them too, the V8 will take you from a standing start to 62mph in 4.6 seconds, which is just 0.3 of a second slower than the W12. The W12 also has a top speed of 198mph compared to the V8's 188mph, something which is hardly going to pose a problem when it comes to real world motoring.

Having had the pleasure of driving both I can confidently say that there isn't a great deal between them.

The V8 gets off to a good start the instant you start the engine up.

Bentley engines have always been known for making wonderful noises and the deep throaty growl of this V8 is no exception and eminently pleasing on the ear.

One of the great things about the latest Continental is that it feels lighter and more agile than its predecessor. To drive it is both thrilling and fun in equal measure and V8 drivers are in no way short-changed when it comes to delivering blistering performance and handling, even if the V8 delivers 67bhp less than the W12.

Despite the relative frugality of the V8 the chances are you will want to drive it in the spirited manner which is no doubt intended by its makers, meaning you'll end up with actual fuel economy that will fall short of that 26.7mpg figure. However, it is pleasing to be behind the wheel of a Bentley where you get the sense you're not actually watching the needle on the fuel gauge move from right to left.

In regular drive mode the V8 is swift and smooth but engage the Sport mode and everything moves up a level, with edgier performance and harder suspension settings to sharpen up its handling. You can further enhance the 'sports' experience by adjusting the damper settings accordingly. This is done easily through the touchscreen multimedia system - another welcome new addition to the latest Continental.

The car also boasts an all-new interior which seems to take opulence to a new level. The woodworking craftsmanship in particular stands out but everything impresses, including the new lighter seats, use of leather and switchgear too.

All this sumptuousness means the Continental is also perfectly suited to more sedate driving, whether it's cruising on the motorway or undertaking a suburban commute.

Obviously Bentley buyers have deep pockets and while it's unlikely any of them would need to make efficiencies in terms of plumping for the V8 over the W12, choosing between the two represents a real conundrum in terms of which one to go for. Unless one needs to be able to say 'my engine's bigger than yours' then the V8 would almost certainly emerge as the overall winner.