Characteristics of the M112 engine
Manufacture and History
The M112 engine from Mercedes-Benz began production in 1997 at the Stuttgart-Bad Cannstatt Plant and is still in production today. This V-twin six-cylinder engine has been the basis for many Mercedes-Benz models, including the C 320 W203, CLK 320 C208/C209, E 320 W210/W211, ML 320 W163, S 320 W220, SL 320 R129, SLK 320 R170, and some Viano and Vito models. In addition, it was installed on the Chrysler Crossfire. The M112 is known for its reliability, power and durability.
Design and Materials
The M112 engine has an aluminum cylinder block for lightness and excellent thermal performance. It is equipped with an injector feed system, which promotes precise fuel metering and improves performance. The engine configuration is V-shaped, with six cylinders and three valves per cylinder. Piston stroke is 84 mm and cylinder diameter is 89.9 mm. The compression ratio is 10, striking an optimal balance between power and economy.
Performance and Economy
The engine has a displacement of 3,199 cubic centimeters. Depending on the modification, engine output can reach 190 horsepower at 5,600 rpm, 218 hp at 5,700 rpm, or 224 hp at 5,600 rpm. Torque also varies: 270 Nm at 2750 rpm, 310 Nm at 3000 rpm or 315 Nm at 3000 rpm. These characteristics provide excellent dynamic performance and a smooth ride.
For optimum engine performance, it is recommended to use fuel with an octane rating of 95. The engine meets Euro 4 environmental standards, making it quite environmentally friendly.
Fuel and Oil Consumption
Fuel consumption for the E320 W211 with the M112 engine is 14.4 liters per 100 km in the city cycle, 7.5 liters on the highway and 9.9 liters in mixed mode. Oil consumption can reach up to 800 grams per 1000 km, which is the norm for powerful engines. The M112 is suitable for a range of viscosities including 0W-30, 0W-40, 5W-30, 5W-40, 5W-50, 10W-40, 10W-50, 15W-40 and 15W-50.
Maintenance and Resource
The engine oil capacity is 8.0 liters, and approximately 7.5 liters is filled when changing the oil. The recommended oil change interval is 7000-10000 km to maintain optimum engine performance. The operating temperature of the engine is about 90 degrees Celsius.
According to the factory data the exact engine life is not specified, but in practice the M112 engine demonstrates the resource exceeding 300 thousand kilometers, which indicates its high reliability and durability.
Tuning and Potential
The M112 engine has significant tuning potential, allowing for up to 500 or more horsepower. This makes it an attractive choice for car enthusiasts and professionals looking to improve the performance of their vehicles without significantly sacrificing engine life.
The M112 engine from Mercedes-Benz is a high-tech and reliable powertrain that provides excellent dynamic performance and long service life. Its versatility and high tuning potential make it a popular choice for many Mercedes-Benz models, as well as some Chrysler models. Thanks to its design and the use of modern technology, the M112 remains a relevant and sought-after engine even years after its production began.
Reliability of the Mercedes M112 E32 3.2 engine
Another version of the six-cylinder engine from Mercedes, with a working volume of 3.2 liters, which came out in 1997 and replaced the inline M104 E32. The new 112 family was formed from a number of different engines: the M112 E24, M112 E26, M112 E28, M112 E32 ML and M112 E37. Unlike its predecessor, in the M112 it was decided to move away from the in-line type of engine and build the new sixes in a V-shaped version with an angle of camber of 90 °, which allowed to increase the compactness of the power plant and maximize the unification of V6 and V8 M113, and to balance the torque from the forces of the second order, a balancer shaft was added. At the same time, when choosing the material for the cylinder block, it was decided to abandon heavy cast iron and make a choice in favor of lightweight aluminum, this step had a very positive impact on the overall weight of the engine.
The cylinder heads are aluminum, single-shaft (SOHC) with three valves per cylinder: two intake valves, one exhaust valve. The diameter of the intake valves is 36 mm, and the exhaust valves are 41 mm. The M112 has a variable valve timing system, hydrocompensators, and a variable length intake manifold.
The timing system uses a chain with an average service life of about 200 thousand kilometers. The control system is Bosch Motronic ME 2.0.
The engine was designed for Mercedes models with the index 320.
In parallel with the six-cylinder M112 E32, a V8 unified with it was produced under the name M113 E43. The next step in the development of V6 from Mercedes-Benz was M 272 KE/DE 35, introduced in 2004 and smoothly replaced the 112 series.
M 112 E 32 engine modifications
- M112.940 (1997 – 2003) – version with 218 hp at 5700 rpm, 310 Nm of torque at 3000 rpm. It was installed on Mercedes-Benz CLK 320 C208.
- M112.941 (1997 – 2002) – analog for Mercedes-Benz E 320 W210. Engine power is 224 hp at 5600 rpm, torque is 315 Nm at 3000 rpm.
- M112.942 (1997 – 2005) – analog M 112.940 for Mercedes-Benz ML 320 W163.
- M112.943 (1998 – 2001) – analog of M 112.941 for Mercedes-Benz SL 320 R129.
- M112.944 (1998 – 2002) – analog of M 112.941 for Mercedes-Benz S 320 W220.
- M112.946 (2000 – 2005) – analog M 112.940 for Mercedes-Benz C 320 W203.
- M112.947 (2000 – 2004) – analog M 112.940 for Mercedes-Benz SLK 320 R170.
- M112.949 (2003 – 2006) – analog of M 112.941 for Mercedes-Benz E 320 W211.
- M112.951 (2003 – present) – version for Mercedes-Benz Vito 119/Viano 3.0 W639, power 190 hp at 5600 rpm, torque 270 Nm at 2750 rpm.
- M112.953 (2000 – 2005) – analog of M 112.940 for Mercedes-Benz C 320 4Matic W203.
- M112.954 (2003 – 2006) – analog of M 112.941 for Mercedes-Benz E 320 4Matic W211.
- M112.955 (2002 – 2005) – analog of M 112.940 for Mercedes-Benz Vito 122/Viano 3.0 W639, CLK 320 C209.
Problems and disadvantages of Mercedes M112 3.2 liter engines
- High oil consumption. The cause of serious oil consumption is often the wear of oil caps and is solved by their replacement. The second option is contaminated with carbon deposits crankcase gas ventilation, in this case cleaning is necessary.
- Oil leaks. The weak point in terms of leaks M112 is the seal of the oil heat exchanger, replacement of the gasket will help.
Besides, after ~80 thousand km the crankshaft pulley damper, crankshaft sensor tend to delaminate, injectors die from low-quality gasoline after ~70-80 thousand km, which leads to loss of power and problems with engine operation. In general, with a normal approach (regular maintenance, high-quality gasoline and oil), the M112 engine is quite reliable, has a motor resource of about 300+ thousand km and you should not expect any serious troubles from it.
Mercedes M112 engine tuning
Chip tuning. Compressor
The M112 engine has an excellent margin for increasing power and for this purpose the market provides a wide range of tuning accessories. The easiest and least complicated step on this path can be the atmospheric version. We will need sport camshafts Schrick 256/268 (or other), cold intake, catalyst-free exhaust or fully sport exhaust and appropriate firmware. The output will be about 250 hp.
A more powerful city engine can be built by installing a mechanical supercharger. There are ready compressor kits (from Kleemann for example), which do not require replacement of the piston, the standard motor will withstand pressure up to 0.5 bar. Together with E32 ML AMG injectors, fuel pump, 3″ outlet, the output will reach ~340 hp and the engine will be much closer to the M112 E32 ML AMG, but the cost of pleasure is very high. For even more power, you need to change the pistons, lower the compression ratio, port the cylinder head and boldly blow far beyond 0.5 bar.
MOTOR RATING: 4+