The company’s top models, the 7-Series sedan, 8-Series coupe, and Rolls-Royce Silver Seraph, were equipped with the 5.4-liter 12-cylinder BMW M73 or M73B54 engine from 1994 to 2002. An upgraded version of the motor, identified by the index M73B54TU or M73TU, debuted in 1998.
The engine was installed on:
- BMW 7-Series E38 in 1994 – 2001;
- BMW 8-Series E31 in 1994 – 1999;
- Rolls-Royce Silver Seraph 1 in 1998 – 2002.
Specifications
| Production years | 1994-2002 |
| Displacement, cc | 5379 |
| Fuel system | distributed injection |
| Power output, hp | 326 |
| Torque output, Nm | 490 |
| Cylinder block | aluminum V12 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 85 |
| Piston stroke, mm | 79 |
| Compression ratio | 10.0 |
| Features | no |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | no |
| Recommended engine oil | 5W-40 |
| Engine oil capacity, liter | 8.5 |
| Fuel type | petrol |
| Euro standards | EURO 3 |
| Fuel consumption, L/100 km (for BMW 750iL 1995) — city — highway — combined |
19.6 8.6 13.3 |
| Engine lifespan, km | ~350 000 |
Disadvantages of the M73B54 engine
First of all, 20 liters of fuel per 100 kilometers shouldn’t make owners feel ashamed;
Air leakage in the intake is the primary cause of the motor’s erratic operation;
The timing chain and sprockets frequently need to be replaced closer to 200–250 thousand kilometers; this power unit already uses a respectable amount of oil on runs over 200,000 kilometers; however, leaks from the water pump or the rear crankshaft oil seal are frequently discovered here.