MERCEDES-BENZ has increased the performance and efficiency of its largest V6-engined E-Class.

Dubbed E350, it replaces the E320 in the two-and-a-half year-old W211 range.

The all-new 3.498-litre V6, first seen here in the latest-generation SLK350 late last year, produces 200kW of power and 350Nm of torque – with the latter arriving as low as 2500rpm.

This compares to the outgoing E320’s 165kW and 315Nm outputs.

It’s enough to propel the E350 sedan from 0-100km/h in 6.9 seconds on the way to an electronically limited 210km/h maximum speed.

That’s 0.8 seconds faster than the E320. The S211 E350 Estate does it in 7.1 seconds – a 1.4-second improvement.

Nevertheless, fuel use drops to 9.7L/100km for the E350 sedan and 9.9 for the wagon. These European consumption averages are down 0.2 and 0.7L/100km respectively.

A large part of this lightweight construction (with aluminium crankcase and cylinder-head) 24-valve quad-cam engine’s efficiency gains over its eight-year-old 18-valve V6 predecessor is the adoption of variable camshaft adjustment on both the intake and exhaust sides.

The engine speed can also determine the length of the intake manifold for optimum torque output – around 87 per cent from 1500rpm.

A newly developed ‘tumbling’ air-fuel mixing device at the end of the manifold’s intake ducts (christened "tumble flaps" by Mercedes) assist combustion for the benefit of fuel economy.

This, along with the fuel injection system, ignition and other various functions are controlled by a Bosch ME 9.7 engine management system that communicates and exchanges information with various other electronic control units.

Other noteworthy engine features include a 20 per cent reduction in the weight of the forged steel connecting rods, low-friction aluminium-silicon cylinder liner technology, a forged crankshaft fitted with four counterweights for reduced vibrations, and a balancer shaft between the cylinder banks for extra smoothness.

Aiding the E350’s fire, frugality and refinement is the adoption of Mercedes’ acclaimed (and world’s sole non-CVT) seven-speed automatic (7G-TRONIC), ousting the old five-speed auto in the E320.

Available with optional steering wheel-mounted gearshift buttons, Mercedes says the 7G-TRONIC’s intelligent shift control systems make the most of the new V6’s benefits via a wider spread of ratios.

The transmission also has the capability of shifting down as many as four gear ratios if conditions demand, rather than moving through a strict order of gears.

Compared to the old five-speeder, the 7G-TRONIC’s shift times are also measurably faster. Plus a torque converter lock-up clutch largely eliminates slip and thus power losses.

Meanwhile, mirroring BMW’s ‘Sport’ package is Mercedes’ own of the same name that’s due for a May debut as an option on all sedan and wagon petrol E-Classes bar the base E240 (meaning the E200 Kompressor, E350 and E500 V8).

It includes a firmer suspension configuration, more direct speed-dependent steering, a revised exhaust tune, new 18-inch alloy wheels on wide rubber, silver-painted brake callipers and perforated front disc brakes, and oval stainless steel exhaust pipes.

Inside there is a sports steering wheel with gearshift paddles and some extra metallic and leather trim enhancements.

The Sport Package prices begin from $2000 depending on which model it is ordered with.

Additionally, an AMG sports package (18-inch wheels, exhaust tailpipes and floor mats) is also appearing from May, replacing the previous ‘Bodystyling’ package.

Both it and the new V6 engine are moves aimed at bolstering the E-Class’ appeal against a Japanese luxury segment invasion courtesy of this month’s all-new Lexus GS and Honda’s Mk4 Legend later on.

Sales inroads from the newer BMW 5 Series (which soon inherits a re-engineered, 190kW 530i) and the recently released and much-improved Audi A6 also has Mercedes on high alert, even though the W211 continues to lead its luxury segment.

Last year it managed 2520 units against the 5 Series’ 1982, 403 A6s, 266 Saab 9-5s, 231 Jaguar S-Types, 116 GS’, 61 Volvo S80s and just three of Honda’s ’96-vintage Legends.