E430_4MATIC

Has anyone else contemplated these various models?

I have a 2000 E430 4Matic which I expect to be trading for a W211 4Matic wagon.

I drove an E320 and felt it was underpowered and strained. The E500 felt very comfortable and similar to what I am used to. I have not yet driven an E350 but have read many positive reviews.

Another vehicle I think I should test drive is BMW's 530xi sport wagon. Gas mileage is better than the MB's and it has an inline 6, like my late 300CE, which should be smooth, unlike MB's V6.

Any thoughts will be appreaciated!

Bode

With regards to comparing the E350 vs 530xi, the MB M272 E35 engine in combination with the 7sp auto gearbox is actually a very powerful and sweet combination. It happily revs to the 6200 redline without much noise and has loads of torque throughout the range (87% of max troque already at 1500 rpm, 100% from 2400 to 5000 rpm).

There is a balancing shaft in this V-6 which cancels out the primary and secondary acceleration forces, so in effect achieves the same smooth running behaviour than the inline 6.

Fuel consumption between the 530i and E350 is very similar, as far as I have seen any hard data on that. The aerodynamic form factor on the e-class is outstanding (Cw = 0.26, not matched by the 5-series), helping both to reduce noise at higher speeds and achieving good fuel economy.

While the 530i engine is no doubt full of good technology as well, I have copied a "little" write up on the M272 I kept from an earlier article on the introduction of the E350 below. Having studied (Mech Eng) and worked on engines for a while, it is pretty much the ultemate of latest engine design (short of direct fuel injection - CGI as applied on the CLS350).

In the end the choice between the various engines and makes is probably a matter of taste, your taste.

Technology is very close, the mercedes is definitely way up there and in my mind still a notch better (I drive a MB afterall...), and as you probably would have guessed, the better sport/comfort/looks package for my taste.

Have fun with the choice between these fine cars.

(On re-read, as you do...I realize the 4 matic still uses the 5sp auto gearbox. I think the line of tought still holds up very much so)

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The new E350 V6 engine in the E-Class: Power to spare

Fuel consumption lowered by up to six percent despite more output

Powerful torque of 350 Nm between 2400 and 5000 rpm

Output, torque, fuel consumption, comfort and exhaust emissions - these were the task areas - all of them equally important - during the development of the V6 engine in the new E 350. The up-to-date six-cylinder unit sets standards in each of these disciplines, offering technical innovations which do not constitute individual solutions but have a positive effect on various aspects.

Mercedes engineers already created important conditions for exemplary performance characteristics with four-valve technology and the four overhead camshafts, but this was not enough in itself. They also developed a system which enables the interaction of the 24 valves to be controlled according to need - depending on the engine load - and which ensures a split-second gas exchange in the cylinders: continuously variable camshaft adjustment. This means that the angles of both the intake and exhaust camshafts can be continuously varied by 40 degrees to make sure that the valves open and close at the most favourable point in any driving situation.


At low engine loads this technology is used to direct exhaust gases back to the intake manifold from the combustion chamber. To achieve this, the camshafts are controlled in such a way that the exhaust valves remain open for a short time while the intake valves are opening. During this brief period a portion of the exhaust gases is able to escape from the exhaust to the intake duct, assisted by the vacuum pressure in the intake manifold. This valve overlap when venting the used gases and taking in the fresh mixture enables an efficient internal exhaust gas recirculation process to take place. This reduces the energy losses during load changes in the cylinders - resulting in a significantly lower fuel consumption.

At higher engine loads the camshaft adjustment is used to optimise the valve overlap as a function of the engine speed in such a way that the combustion chambers are optimally supplied with fresh mixture - thus ensuring a high output and torque.

The camshafts are controlled by electrohydraulically operated vanetype actuators. These are located at the front ends of the camshafts and are controlled by four integral hydraulic valves. The intake camshafts are driven by a duplex chain, while the exhaust camshafts are driven directly by the intake camshafts via a pair of gears. In addition to the four-fold, variable camshaft adjustment system, a number of other features contribute to the exemplary performance characteristics of the V6 engine:

Flow-optimised intake ducts with innovative tumble flaps for the best possible throughput
Specially developed valves with a shaft diameter of only six millimetres, which only slightly disturb the flow in the intake duct
Compact combustion chambers for high compression (10.7:1) and good volumetric efficiency
The newly developed, two-stage variable intake manifold.

The developers of the V6 devoted great attention to all measures which would contribute to the best possible aspiration of the engine. Powerful computer programmes assisted with the flow calculations, helping for instance to optimise the intake air flow from the dual-flow air filter, where the lines come together at the hot-film air flow sensor (HFM). For an efficient airflow, its housing is oval in shape and accommodates an electrically heated sensor which determines the intake air mass and provides the engine computer with important information for the composition of the fuel/air mixture.

The intake module is produced in well-proven magnesium and allows the air intake to be varied according to the load conditions and engine speed. The length of the intake ducts leading to the cylinders is altered by means of flaps: at high engine speeds - from approx. 3500 rpm - the flaps are open and the air flows into the combustion chambers over a short distance, producing a high output. At low engine speeds the flaps are closed to increase the length of the intake duct. This produces pressure waves which support the intake process and significantly improve the torque yield in the lower engine speed range. 305 Newton metres of torque - 87 percent of the maximum - is already available from 1500 rpm.

Turbulent airflow: tumble-flaps in the intake ducts

The special feature of the intake manifold in the Mercedes six-cylinder engine is the electropneumatically driven flaps at the end of each intake duct. These make a considerable contribution to fuel economy. Mercedes engineers refer to these as tumble-flaps, which describes their function: they literally cause the fuel/air mixture to tumble, thereby increasing the turbulence of the airflow and allowing it to reach the combustion chambers at a higher speed for more even distribution. The result is more efficient and complete combustion.

Under partial load the tumble-flaps swivel up, optimise the airflow and thereby increase the speed of combustion - an advantage which is particularly noticeable in view of the leaner mixture caused by exhaust gas recirculation and which reduces the fuel consumption. The tumble flaps are not required under higher engine loads, therefore they are fully recessed into the intake manifold and do not disturb the intake process. This situation-related control of the tumble-flaps is based on a prestored, logic-controlled microcomputer program.

Thanks to the tumble-flaps in the intake ducts, the fuel consumption of the V6 engine can be reduced by up to 0.2 litres per 100 kilometres depending on the engine speed - while improving smoothness at the same time.

Combustion of the fuel/air mixture is via a direct coil ignition system. The spark plugs project into the cylinders from a central position between the four valves, with the ignition coils arranged immediately above them.

The tumble-flaps, fuel injection, ignition and numerous other engine functions are controlled by the Bosch ME 9.7 engine management system, which communicates and exchanges information with the other onboard electronic control units via a databus. In the interests of short electrical paths, the engine management unit is centrally located above the intake system and integrated into the engine design.

The microprocessor in the control unit continuously diagnoses all engine functions. This includes monitoring of the catalytic converters and ignition system, electrical checks on the purge valve and controlling the lambda sensors. Should one these major emission control systems develop a fault, the warning "Check Engine" appears in the instrument cluster display. The data are stored in memory at the same time, allowing service technicians to identify the cause at once and remedy the fault.

Mercedes engineers have made a further contribution to fuel economy with an intelligent heat management system. For example, circulation of the coolant is prevented during the warm-up phase so that the engine reaches its normal operating temperature more rapidly. This leads to an improved oil flow and therefore significantly less friction within the engine. Exhaust emissions are also reduced as a result. Even when the engine is warm and under full load, the heat flows are controlled to ensure that the engine oil and coolant are always at their ideal temperature. This is done by a new, logic-controlled thermostat which is active under all operating conditions.

Progress in figures: more driving pleasure, lower fuel consumption

A comparison between the new E 350 and the previous E 320 shows the positive effects of the new technology in the V6 engine on performance and fuel consumption:

Acceleration from 0 -100 km/h: The E 350 Saloon takes 6.9 seconds to reach 100 km/h from standstill, which is 0.8 seconds faster than its predecessor. The acceleration time for the Estate is 1.4 seconds shorter than for its predecessor, at 7.1 seconds.
Flexibility: The new E 350 Saloon absolves an intermediate sprint from 60 to 120 km/h in 6.9 seconds, and is therefore 1.7 faster than the E 320. The Estate takes 7.2 seconds, which is 2.2 seconds less than the preceding model.
Maximum speed: The maximum speed of the Saloon is increased from 245 to 250 km/h, and that of the Estate from 233 to 250 km/h (electronically limited).
Fuel consumption: Despite the 21 percent higher output of the new V6 engine, the fuel consumption of the Saloon is reduced by 0.2 to 9.7 litres per 100 kilometres compared to the E 320 (NEDC combined consumption). For the Estate the fuel saving is 0.7 litres per 100 kilometres

Lightweight construction: aluminium crankcase and cylinder head

The cylinder head and crankcase of the new V6 engine are of aluminium. The pistons, connecting rods and cylinder liners also reflect the latest design principles, which not only contribute to weight reduction but also have a noticeably positive effect in terms of responsiveness and smooth running. The lower the moving masses in the crankcase, the lower the vibrations and the more agile the engine's response to movements of the accelerator.

The pistons are made of iron-coated aluminium. Taking the valve angle (28.5 degrees) into account, their crowns are shaped to provide a favourable combustion chamber.

Mercedes engineers have reduced the weight of the forged steel connecting rods by around 20 percent compared to other V6 engines, thereby making a major contribution to the refined running characteristics of the new six-cylinder unit.
The cylinder liners feature low-friction surfaces in aluminium-silicon technology, a system which has proved successful in other car engines by Mercedes-Benz. Other advantages include high dimensional stability, exemplary thermal characteristics and low weight. The weight saving compared to conventional cast-iron liners is approx. 500 grams per cylinder.
The forged crankshaft is fitted with four counterweights. Four wide crank-shaft bearings with transverse reinforcements attached to the crankcase likewise ensure that vibrations are reduced.
A balancer shaft between the two banks of cylinders compensates the free vibrations that are inherent to a V6 engine and ensures exemplary smoothness. It counter-rotates with the crankshaft at the same speed.
Audible comfort: noise reduction and sound engineering

In addition to exemplary output and torque characteristics, a favourable fuel consumption and smooth running, the new V6 engine offers audible progress. Where noise comfort is concerned, Mercedes engineers have devoted a great deal of technical effort towards the engine's acoustics, assessing the volume and frequency of the noise emitted by practically each one of the approx. 210 individual components in the engine - from the crankcase to the engine mountings, and from the pistons to the injection nozzles.

Their aim was to achieve a pleasant noise background in any driving situation. To make this possible they not only measured the absolute noise values, but also eliminated sources of acoustic disturbance which are not particularly loud in themselves, but can become unpleasantly obtrusive with specific frequencies during load or engine speed changes - and which worsen the subjective impression of noise. The air intake system is a good example: as a result of the analyses carried out with the latest measuring techniques, the intake ducts are made from woven Nylon. In contrast to the smooth plastic used previously, this material has a sound-absorbing effect and significantly reduces the intake noise.

The subject of noise engineering is increasingly becoming a major task of engine developers, especially since engineers are called upon to resolve the conflict of aims between a low level of drive-by noise and a pleasant, throaty exhaust note. In the case of the new six-cylinder engine the specialists followed a concept of reducing noise while designing the sound. Various measures were therefore adopted to reduce engine noise - from a twin-cartridge air filter with integral resonators to a sound-absorbing mat beneath the bonnet. At the same time the specialists went to work on producing a sonorous six-cylinder sound by emphasising certain pleasant frequencies - especially by specific configuration of the twin-pipe exhaust system.

Two-stage concept: emission control in the engine and by catalytic converters

The emission control concept has a two-stage structure. It is based firstly on sophisticated in-engine features which ensure a low level of untreated emissions, and secondly on a highly effective exhaust gas treatment system using two 1.4-litre near-engine catalytic converters. Each of these is equipped with two lambda sensors - one control and one diagnostic sensor - and is in a linear closed loop. This means that the lambda sensors are already active immediately after the engine is started, providing information about the exhaust gas constituents which the electronic control unit processes to ensure an efficient warm-up phase. The catalytic converters also reach their normal operating temperature more rapidly thanks to the air-gap-insulated, stainless steel exhaust manifold.

The in-engine systems include variable camshaft adjustment, which makes efficient internal exhaust gas recirculation possible under part-throttle conditions. The adjustable tumble-flaps in the intake ducts of the V6 engine, which improve the combustion process, also make a major contribution to minimising the engine’s untreated emissions. A secondary air injection system is also used. This has an afterburning effect on the exhaust gases, raising the temperature in the exhaust ducts and enabling the catalytic converter to convert pollutant emissions at an earlier stage. This thermal afterburning also reduces the proportion of carbon monoxide and hydrocarbons in the exhaust gases.