|When BMW designs a new engine, it is news. After all, almost anyone can design a car, but what will they use to power it?
The new 3.0
liter straight-six engine, designated as the M54, is the latest design
from BMW engineers, replacing the M52 engine.
The new power unit was featured for the first time in the 2001 models including the X5, the 3 Series Coupe,
Sedan, Touring, Convertible, Z3
Roadster, and Z3 Coupe.
Click here for a history of BMW Six Cylinder engines.
Here are the details on what make this engine so special:
|In an era of V-6 designs, why a straight-six?
- The laws of physics; a straight-six power unit offers the optimum physical configuration for a six-cylinder engine.
- The near perfect inner balance of the straight-six means an absence of free mass forces.
- The straight-six does not require balance shafts and elaborate engine mounts to overcome the inherent vibrations of other designs.
- With valve drive systems becoming more complex, there are engineering advantages in having only one cylinder head and only one valve train.
|The Design of the Straight-Six
More power, more fuel economy. Here's how:
The M54 has an aluminum crankcase with cast cylinder liners. The engine size has been increased from the 2.8 liters of the
M52 model to 3.0 liters by increasing the cylinder stroke from 84.0 to 89.6 mm. With
the increase in engine size, engine power has been increased from 142 kW/193 hp to 170 kW/231 hp. The increase in the opening period of the intake valves resulted in an increase of 3.5 kW/4.8 hp in engine output. The intake and exhaust manifolds
have been streamlined. This improvement contributed 16 kW/22 hp to the increase in engine output. Other refinements result from reducing piston friction and cutting back the engine's idle speed.
|Electronic Throttle Butterfly
The throttle butterfly has now been replaced by a fully electronic version.
The system recognizes the gear in which the car is driving and is thus able to activate an individually programmed throttle butterfly control line for each gear. Cruise control has been integrated within the
electronic throttle butterfly. Since there are no conventional mechanical linkage bars, there is a reduction of gas pedal forces. The phrase "step on the gas" takes on a whole new meaning! The controls stored within the engine management system
have increased to over 600 different operating modes.
The M54 is the most reliable BMW engine ever built. Here's why:
- The camshaft chain drive and the V-belt drive are maintenance-free and designed for the life of the engine.
- Valve clearances are kept consistent throughout the entire running life of the engine by a self-adjusting hydraulic valve clearance mechanism. There is no need to adjust valve clearances, ever.
- There is no need to reset the clutch since it is self-adjusting.
- The air filters and spark plugs only have to be replaced after 100,000 km or 62,000 miles.
- The oil in the transmission and final drive is a lifetime filling not requiring any replacement.
- There is no need for any particular running-in service.
- The BMW Service Interval Indicator informs the driver of the remaining distance until the next oil change. You no longer have to change the oil after a fixed, rigid mileage.
- The engine is able to adjust automatically to all fuel grades between 87 and 98 octane.
- Anti-knock control automatically adjusts the engine's running conditions to the respective fuel grade and quality.
- Please note that the engine's maximum output is only achieved when running on 98 octane premium fuel.