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- Technical article
- Subject
- Engines
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- Section level
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- No ECU-specific applicability
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- Manufacturers
- Not recorded in this older revision
Changes from revision 1 to revision 4
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BMW automotive engine families listed as M51. Specifications below retain the source's separate family and variant labels.
Family specifications
BMW M51
FieldReported valueManufacturerBMWProduction1991-2000ConfigurationInline-6Displacement2.5 L; 152.4 cu in (2,497 cc)Cylinder bore80 mm (3.15 in)Piston stroke82.8 mm (3.26 in)Cylinder block materialCast ironValvetrainSOHC 2 valves x cyl.Compression ratio22.0:1TurbochargerSingle turbo, tds-engines also have an intercoolerFuel systemSwirl-chamber-injectionManagementBosch DDE 2.1Fuel typeDiesel fuel (DIN 51601)Cooling systemWater-cooledPower output85–105 kW (114–141 hp)Torque output222–280 N⋅m (164–207 lb⋅ft)Dry weight132 kg (291 lb)PredecessorBMW M21SuccessorBMW M57
Variant specifications
Description
VersionPowerTorqueYearsM51D25 UL85 kW (115 hp) at 4800 rpm222 N⋅m (164 lb⋅ft) at 1900 rpm1991–1997M51D25 OL105 kW (143 hp) at 4800 rpm260 N⋅m (192 lb⋅ft) at 2200 rpm1991–1996Opel X25DT96 kW (130 hp) at 4800 rpm250 N⋅m (184 lb⋅ft) at 1400 rpm1994–2001M51D25TÜ UL85 kW (115 hp) at 4800 rpm230 N⋅m (170 lb⋅ft) at 1900 rpm1996–1998M51D25TÜ OL105 kW (143 hp) at 4800 rpm280 N⋅m (207 lb⋅ft) at 2200 rpm1996–1998M51D25TÜ OL105 kW (143 hp) at 4600 rpm280 N⋅m (207 lb⋅ft) at 2200 rpm1998–2000M51D25M1100 kW (136 hp) at 4400 rpm270 N⋅m (199 lb⋅ft) at 2300 rpm1995-2001
BMW automotive engine directory
Design, development and variant notesThe M51 is a 2,497 cc indirect-injection six-cylinder diesel with a chain-driven SOHC head, iron block and aluminium cylinder head. A Bosch VP37 electronically controlled distributor pump supplies fuel.Some turbocharged versions have an intercooler and use the tds designation. Wikipedia identifies DDE 2.1 on early engines and DDE 2.2 after the first technical revision, with application-specific differences.Data adapted from the cited Wikipedia revision by Wikipedia contributors under CC BY-SA 4.0. Production dates and fitments reflect that revision; verify the exact engine code, market and vehicle before applying a specification.
Sources
Curated reference notes. Applicability follows the cited sources; hardware testing by this wiki is not implied.
Wikipedia: List of BMW engines. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1382309748; accessed 2026-11-10.Wikipedia: BMW M51. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1380863475; accessed 2026-11-10.
Further Wikipedia-sourced detailsThe following additional information is drawn from the cited Wikipedia revision by Wikipedia contributors, available under CC BY-SA 4.0. An open-ended date reflects the source snapshot, not confirmed current production or fitment.Additional recorded applicationsSource version or ratingVehicle application as recordedDescription1991 - 1996 BMW 325td (M51D25 UL)Description1996 - 1998 BMW 325td (M51D25TÜ UL)Description1993 - 1996 BMW 325tds (M51D25 OL)Description1996 - 1998 BMW 325tds (M51D25TÜ OL)Description1992 - 1996 BMW 525td (M51D25 UL)Description1991 - 1996 BMW 525tds (M51D25 OL)Description1996 - 2000 BMW 525tds (M51D25TÜ OL)Description1996 - 2000 BMW 525td (M51D25TÜ UL)Description1996 - 2000 BMW 725tds (M51D25TÜ OL)Description1995 - 2001 Range Rover (P38A)Description1994 - 2001 Opel Omega BDescription1992 UMM Alter II (single example; engine, gearbox, and electronics were fitted by BMW in Munich)Unaccented search spellingsSearch equivalents using U in place of Ü: M51D25TU.Page organisation changed
Rendered revisions
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Revision 1: BMW M51 engines
BMW automotive engine families listed as M51. Specifications below retain the source's separate family and variant labels.
Family specifications
BMW M51
| Field | Reported value |
|---|
| Manufacturer | BMW |
| Production | 1991-2000 |
| Configuration | Inline-6 |
| Displacement | 2.5 L; 152.4 cu in (2,497 cc) |
| Cylinder bore | 80 mm (3.15 in) |
| Piston stroke | 82.8 mm (3.26 in) |
| Cylinder block material | Cast iron |
| Valvetrain | SOHC 2 valves x cyl. |
| Compression ratio | 22.0:1 |
| Turbocharger | Single turbo, tds-engines also have an intercooler |
| Fuel system | Swirl-chamber-injection |
| Management | Bosch DDE 2.1 |
| Fuel type | Diesel fuel (DIN 51601) |
| Cooling system | Water-cooled |
| Power output | 85–105 kW (114–141 hp) |
| Torque output | 222–280 N⋅m (164–207 lb⋅ft) |
| Dry weight | 132 kg (291 lb) |
| Predecessor | BMW M21 |
| Successor | BMW M57 |
Variant specifications
Description
| Version | Power | Torque | Years |
|---|
| M51D25 UL | 85 kW (115 hp) at 4800 rpm | 222 N⋅m (164 lb⋅ft) at 1900 rpm | 1991–1997 |
| M51D25 OL | 105 kW (143 hp) at 4800 rpm | 260 N⋅m (192 lb⋅ft) at 2200 rpm | 1991–1996 |
| Opel X25DT | 96 kW (130 hp) at 4800 rpm | 250 N⋅m (184 lb⋅ft) at 1400 rpm | 1994–2001 |
| M51D25TÜ UL | 85 kW (115 hp) at 4800 rpm | 230 N⋅m (170 lb⋅ft) at 1900 rpm | 1996–1998 |
| M51D25TÜ OL | 105 kW (143 hp) at 4800 rpm | 280 N⋅m (207 lb⋅ft) at 2200 rpm | 1996–1998 |
| M51D25TÜ OL | 105 kW (143 hp) at 4600 rpm | 280 N⋅m (207 lb⋅ft) at 2200 rpm | 1998–2000 |
| M51D25M1 | 100 kW (136 hp) at 4400 rpm | 270 N⋅m (199 lb⋅ft) at 2300 rpm | 1995-2001 |
BMW automotive engine directory
Data adapted from the cited Wikipedia revision by Wikipedia contributors under CC BY-SA 4.0. Production dates and fitments reflect that revision; verify the exact engine code, market and vehicle before applying a specification.
Sources
Curated reference notes. Applicability follows the cited sources; hardware testing by this wiki is not implied.
Revision 4: BMW M51 engines
BMW automotive engine families listed as M51. Specifications below retain the source's separate family and variant labels.
Family specifications
BMW M51
| Field | Reported value |
|---|
| Manufacturer | BMW |
| Production | 1991-2000 |
| Configuration | Inline-6 |
| Displacement | 2.5 L; 152.4 cu in (2,497 cc) |
| Cylinder bore | 80 mm (3.15 in) |
| Piston stroke | 82.8 mm (3.26 in) |
| Cylinder block material | Cast iron |
| Valvetrain | SOHC 2 valves x cyl. |
| Compression ratio | 22.0:1 |
| Turbocharger | Single turbo, tds-engines also have an intercooler |
| Fuel system | Swirl-chamber-injection |
| Management | Bosch DDE 2.1 |
| Fuel type | Diesel fuel (DIN 51601) |
| Cooling system | Water-cooled |
| Power output | 85–105 kW (114–141 hp) |
| Torque output | 222–280 N⋅m (164–207 lb⋅ft) |
| Dry weight | 132 kg (291 lb) |
| Predecessor | BMW M21 |
| Successor | BMW M57 |
Variant specifications
Description
| Version | Power | Torque | Years |
|---|
| M51D25 UL | 85 kW (115 hp) at 4800 rpm | 222 N⋅m (164 lb⋅ft) at 1900 rpm | 1991–1997 |
| M51D25 OL | 105 kW (143 hp) at 4800 rpm | 260 N⋅m (192 lb⋅ft) at 2200 rpm | 1991–1996 |
| Opel X25DT | 96 kW (130 hp) at 4800 rpm | 250 N⋅m (184 lb⋅ft) at 1400 rpm | 1994–2001 |
| M51D25TÜ UL | 85 kW (115 hp) at 4800 rpm | 230 N⋅m (170 lb⋅ft) at 1900 rpm | 1996–1998 |
| M51D25TÜ OL | 105 kW (143 hp) at 4800 rpm | 280 N⋅m (207 lb⋅ft) at 2200 rpm | 1996–1998 |
| M51D25TÜ OL | 105 kW (143 hp) at 4600 rpm | 280 N⋅m (207 lb⋅ft) at 2200 rpm | 1998–2000 |
| M51D25M1 | 100 kW (136 hp) at 4400 rpm | 270 N⋅m (199 lb⋅ft) at 2300 rpm | 1995-2001 |
BMW automotive engine directory
Design, development and variant notes
The M51 is a 2,497 cc indirect-injection six-cylinder diesel with a chain-driven SOHC head, iron block and aluminium cylinder head. A Bosch VP37 electronically controlled distributor pump supplies fuel.
Some turbocharged versions have an intercooler and use the tds designation. Wikipedia identifies DDE 2.1 on early engines and DDE 2.2 after the first technical revision, with application-specific differences.
Data adapted from the cited Wikipedia revision by Wikipedia contributors under CC BY-SA 4.0. Production dates and fitments reflect that revision; verify the exact engine code, market and vehicle before applying a specification.
Sources
Curated reference notes. Applicability follows the cited sources; hardware testing by this wiki is not implied.
Further Wikipedia-sourced details
The following additional information is drawn from the cited Wikipedia revision by Wikipedia contributors, available under CC BY-SA 4.0. An open-ended date reflects the source snapshot, not confirmed current production or fitment.
Additional recorded applications
| Source version or rating | Vehicle application as recorded |
|---|
| Description | 1991 - 1996 BMW 325td (M51D25 UL) |
| Description | 1996 - 1998 BMW 325td (M51D25TÜ UL) |
| Description | 1993 - 1996 BMW 325tds (M51D25 OL) |
| Description | 1996 - 1998 BMW 325tds (M51D25TÜ OL) |
| Description | 1992 - 1996 BMW 525td (M51D25 UL) |
| Description | 1991 - 1996 BMW 525tds (M51D25 OL) |
| Description | 1996 - 2000 BMW 525tds (M51D25TÜ OL) |
| Description | 1996 - 2000 BMW 525td (M51D25TÜ UL) |
| Description | 1996 - 2000 BMW 725tds (M51D25TÜ OL) |
| Description | 1995 - 2001 Range Rover (P38A) |
| Description | 1994 - 2001 Opel Omega B |
| Description | 1992 UMM Alter II (single example; engine, gearbox, and electronics were fitted by BMW in Munich) |
Unaccented search spellings
Search equivalents using U in place of Ü: M51D25TU.