THE new generation Mercedes-Benz CL and revised engines in the S-Class will be in dealerships in October to build on the swing towards more upmarket and quality models demanded by British buyers.

Latest sales figures show an underlying trend towards customers seeking better cars which they may well plan to keep for longer than before. Take a little pain now for long term gain seems to be the message driving sales.

At the heart of the sleek new CL coupe and appearing in the bigger S-Class saloons with short or long wheelbases, are the very latest V8 petrol and V6 diesel engines.

In the CL and S63 AMG models the new V8 also brings massive benefits to these high performance coupes and saloons and which are further refined for more dynamic driving.

By moving to direct fuel injection with sophisticated high performance ignition and linked to careful re-design and manufacturing to reduce friction, Mercedes has managed to raise power output by 12.5%, cut fuel bills by 29% and emissions by about the same depending on which model uses the  newest 258bhp 3.0 V6 diesel.

In the case of the mighty S and CL 500 petrol fuelled 4.6 V8, the 435bhp models show gains of 12% more power, torque is up almost a third and consumption is down 22% over previous versions, all remarkable achievements in cars of such size and tipping the scales at over 2,000kg.

The CL and S63 AMG 5.5 V8 new bi-turbo engine replaces the naturally aspirated 6.2 V8 and has been completely retuned over the standard new V8 to punch out a minimum 544bhp, emit 244g/km and it propels the 2,120kg car to 62mph from rest in 4.5 seconds.

They are the first of a new family of power units from the car maker and they have been designed to be part of any hybrid powertrain in future.

Mercedes has employed the latest technology such as seven-speed standard automatic transmission and stop/ start eco-technology to ease fuel bills and some clever additional technical features including active lane assist, blind spot monitors, radar and camera assistance systems and even cross wind stabilisation, which uses sensors on the suspension to measure cross-wind hitting the car from any direction and then beefing up the resistance, all in milli-seconds.

Inside there is the latest split view technology using thin film transistor which allows driver and passenger to simultaneously view different displays, as well as powerful navigation and sound packages.

The new CL has a dramatically different front end incorporating new grille, headlamps, bumper and bonnet with LED daytime lights and there are new tail lights. The rear deck follows a more continuous line from the wings and the coupe roofline is different.

The best selling year for the CL Class in the UK was 2007 when 729 went through dealerships but the arrival of the recession halved that figure the following year and it slipped further again last year and to date in 2010 has just topped 100 units. The arrival of the new CL is expected to see sales start climbing again.

Mercedes CL and S Classes product manager Claire McAlistair said, "We expect renewed interest in these cars thanks to their much greater fuel efficiency and increased performance combined with tremendous technical features. The latest engine technology will transform the driving experience for users and put us at the forefront of people's minds."

The new CL500 BlueEfficiency will cost £89,425, while the CL63 AMG models cost from £111,985. Average rises across this range are under 3%.

In the revised S-Class, the new 350 BlueTec diesel will replace the outgoing 350 CDI with more outright power, greater torque, lower emissions and consumption. At best it gives 41.5mpg and emits 177g/km, one of the cleanest and most economical diesels and means it already meets the 2014 EU6 standards. The petrol bi-turbo version can exceed 30mpg thanks to stop-start technology.

Visually the latest S-Class gets minor cosmetic changes to the front end and integrated rear tailpipes and there are subtle changes inside as well.

Mercedes has included more standard equipment such as the multi-function media interface and top versions have a new Bang & Olufsen system, which combined add more than the 1.6% price rise introduced with the changes.

The latest S350 BlueTec enters the range at £58,440, the S500 is £79,810, and the S63 AMG is £109,125.

Conservative Mercedes has found a win-win formula with its newest engines and CL series.

Smoothly, strongly and cleanly, the newest engine ranges power Mercedes higher up the desirability stakes.

With the stop-start on the S-Class you do not have to make a conscious decision to make it work once you have selected the Eco mode and it responds immediately without any worrying delay which can cause panic in heavy traffic.

The big S-Class provides excellent ride and room and it now comes a more refined powertrain as well.

Turning to the bigger selling CL-Class, the new model is immediately visually different and refreshed while under the bonnet and inside its new technology makes it more of a driver's car as well as being a genuine four-seater coupe. Access to the two rear seats is easy and once inside the leg and headroom is very good.

The AMG versions of both cars provide still more dynamic driving satisfaction than before thanks to their improved responses, smoothness and quietness, but thankfully the distinctive exhaust note remains to enjoy.