Mercedes-Benz M276 engine

Mercedes-Benz M276 DE35
Overview
Manufacturer	Mercedes-Benz
Production	2010–2018
Layout
Configuration	Naturally aspirated 60° V6
Displacement	3.5 L (3,498 cc)
Cylinder bore	92.9 mm (3.66 in)
Piston stroke	86 mm (3.39 in)
Cylinder block material	Aluminum
Cylinder head material	Aluminum
Valvetrain	DOHC with VVT
Combustion
Fuel system	Direct injected
Fuel type	Gasoline
Oil system	Wet sump
Cooling system	Water cooled
Output
Power output	248–302 hp (185–225 kW; 251–306 PS)
Torque output	340–370 N⋅m (251–273 lb⋅ft)
Chronology
Predecessor	Mercedes-Benz M272
Successor	M276 DE30LA

The Mercedes-Benz M276 engine is a direct injected, gasoline automotive piston V6 engine.^[1]

The M276 engine is not related to the Chrysler Pentastar except for the 60-degree angle, despite that it was developed while Chrysler was still owned by Daimler AG. This can be seen in its 60 degree vee–angle, as opposed to the 90-degree angle of its M272 predecessor. The 60 degree vee–angle eliminates the need for a balance shaft, improving refinement while reducing mechanical complexity. None of the parts are shared at all.^[1][2]

The M276 engine features an aluminum engine block with Nanoslide cylinder coating and dual overhead camshafts with independent variable valve timing on 12 intake and 12 exhaust valves and a new 2–stage timing chain arrangement. The M276 also includes direct injection with piezo–electrically controlled injectors for 2 to 3 sprays per intake stroke in normal operation,^[3] multi–spark ignition that creates up to 4 sparks per cycle,^[3] and the demand–controlled fuel pump, water pump, oil pump and alternator^[3] that reduce parasitic loads.

The first spray of fuel injection creates the base lean burn mixture in the intake cycle, while the later spray(s), up to 4 more times in combustion cycle in difficult conditions for a clean burn, control when and where the ignition starts and how the burn propagates in stratified charge fashion.^[3] In combination with a new smaller and more efficient Variable Valve Timing mechanism on all 4 camshafts, the precise combustion control allows a quicker and smoother re–start of the engine for the stop–start system. This VVT can alter cam timing up to 40 crank degrees with a higher speed than before, and enables limiting the intake charge combined with a normal combustion stroke, thus making the operating process an Atkinson cycle in partial throttle conditions for better fuel efficiency.^[4] These features are also shared with Mercedes' M278 V8 engine, announced at the same time.^[1]

Mercedes–Benz claims that the new engine, in conjunction with the demand–controlled ancillaries and the stop–start system, can produce up to a 24% improvement in fuel economy while increasing power and torque over the M272.^[3] This efficiency improvement led to the various models with this engine being labeled with Blue Efficiency moniker.

Retaining most of the above characteristics, turbocharged smaller displacement DELA 30 variant was introduced in 2013 for C400 (W205) and subsequently offered on other models without the name Blue Efficiency.

For 2014 CLS400, a turbocharged larger displacement variant named DELA 35 came out to the market with a lower boost of 0.7 bar (10 psi) compared to 1.8 bar (26 psi) of DELA30 resulting in the same power and torque ratings at a lower fuel consumption.^[5]

In 2015, a higher boost and a slightly lower compression ratio (10.5:1) were used to create a DE30LA version for AMG models, and is used for many AMG and Mercedes–Benz vehicles since.