# SDI (engine)

The SDI engine is a design of naturally aspirated (NA) direct injection diesel engine developed and produced by Volkswagen Group for use in cars and vans, along with marine engine (Volkswagen Marine) and Volkswagen Industrial Motor applications.
The SDI brand name (derived from "Suction Diesel Injection" or "Suction Diesel Direct Injection", the latter a literal translation of the German: Saugdiesel-Direkteinspritzung) was adopted in order to differentiate between earlier and less efficient indirect injection engines, called SD or "Suction Diesel", which were also produced by Volkswagen Group.
SDI engines are only produced in inline or straight engine configurations; and as they originate from a German manufacture, are designated as either R4 or R5, taken from the German: Reihenmotor. They are available in various displacements (from 1.7 to 2.5 litres), in inline-four (R4 or I4) and inline-five (R5 or I5), in various states of tune, depending on intended application.
The SDI engine is generally utilised in applications where reliability and fuel economy are of primary concern. These engines lack any type of forced induction, hence the use of 'suction' in the title, and their power output is lower than a turbocharged engine of similar displacement. For example, the 2.0 SDI engine fitted to the Volkswagen Golf Mk5 has a peak power output of 55 kilowatts (75 PS; 74 bhp); whereas the same engine in Turbocharged Direct Injection (TDI) form is rated at 103 kilowatts (140 PS; 138 bhp) or 125 kilowatts (170 PS; 168 bhp), depending on specifications.

## SDI engines and applications

SDI engines: specifications, performance and applications :
| model | designation or ID code(s) | engine displacement | peak power at rpm (Directive 80/1269/EEC) | max. torque at rpm | notable design features | notes & application(s) |
| automotive engines |||||||
| 1.7 SDI | AHB, AHG, AKU, AKW | 1,716 cubic centimetres (104.7 cu in) | 44 kW (60 PS; 59 bhp) @ 4,200 | 115 N⋅m (85 lbf⋅ft) @ 2,200 | Bosch VP37 (German: VerteilerPumpe) electronic distributor injection pump | Volkswagen Lupo, SEAT Arosa, Volkswagen Polo (some markets), Volkswagen Caddy Typ 9K |
| 1.9 SDI | ASY, AEY, AGD | 1,896 cubic centimetres (115.7 cu in) | 47 kW (64 PS; 63 bhp) @ 4,200 | 125 N⋅m (92 lbf⋅ft) @ 1,600-2,800 | Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Volkswagen Polo Mk3, Volkswagen Polo Classic, Volkswagen Golf Mk3, Volkswagen Caddy Typ 9U/9K, SEAT Inca, Škoda Octavia (Mk1), Škoda Fabia, Volkswagen Bora (some markets), Volkswagen Jetta King, Volkswagen Jetta Pioneer |
| 1.9 SDI | AGP, AQM | 1,896 cubic centimetres (115.7 cu in) | 50 kW (68 PS; 67 bhp) @ 4,000 | 133 N⋅m (98 lbf⋅ft) @ 1,800 | Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Volkswagen Polo Mk3, Volkswagen Golf Mk4, Volkswagen Caddy Typ 9U/9K, SEAT Ibiza, SEAT Inca, SEAT León Mk1 (1M), Škoda Octavia (Mk1) Volkswagen Bora (some markets) |
| 2.0 SDI PD | BDJ, BST | 1,968 cubic centimetres (120.1 cu in) | 51 kW (69 PS; 68 bhp) @ 4,200 | 140 N⋅m (103 lbf⋅ft) @ 2,200-2,400 | Bosch Pumpe Düse technology | Volkswagen Caddy Typ 2K |
| 2.0 SDI PD | BDK | 1,968 cubic centimetres (120.1 cu in) | 55 kW (75 PS; 74 bhp) @ 4,200 | 140 N⋅m (103 lbf⋅ft) @ 2,200-2,400 | Bosch Pumpe Düse technology | Volkswagen Golf Mk5 |
| 2.5 R5 SDI | AGX | 2,461 cubic centimetres (150.2 cu in) | 55 kW (75 PS; 74 bhp) | 160 N⋅m (118 lbf⋅ft) | Inline-five engine, Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Volkswagen LT28 and LT35 vans (05/96-04/01) |
| marine engines |||||||
| 1.9 SDI | SDI 40–4, SDI 50–4, SDI 60-4 | 1,896 cubic centimetres (115.7 cu in) | 29 kW (39 PS; 39 bhp) @ 2,600 / 37 kW (50 PS; 50 bhp) @ 3,000 / 44 kW (60 PS; 59 bhp) @ 3,600 | 126 N⋅m (93 lbf⋅ft) @ 2,000 / 130 N⋅m (96 lbf⋅ft) @ 2,000 / 129 N⋅m (95 lbf⋅ft) @ 2,000 | Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Small motor cruisers. Optional connection for heater core or hot water preparation for use in sailboats |
| 2.5 R5 SDI | SDI 55–5, SDI 75-5 | 2,461 cubic centimetres (150.2 cu in) | 40 kW (54 PS; 54 bhp) @ 2,500 / 55 kW (75 PS; 74 bhp) @ 3,600 | 155 N⋅m (114 lbf⋅ft) @ 2,250 | Inline-five engine, Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Yachts and motor cruisers |
| industrial engines (80/1269/EEC-rated) |||||||
| 1.9 SDI | 430/BXT | 1,896 cubic centimetres (115.7 cu in) | 30 kW (41 PS; 40 bhp) | | Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Volkswagen Industrial Motor |
| 1.9 SDI | 444 | 1,896 cubic centimetres (115.7 cu in) | 44 kW (60 PS; 59 bhp) @ 3,600 | 130 N⋅m (96 lbf⋅ft) @ 2,200 | Bosch VP37 (VerteilerPumpe) electronic distributor injection pump | Volkswagen Industrial Motor |
    Notes: Volkswagen Marine engines were originally rated according to Directive 80/1269/ EEC. However, some are now being rated to ISO 8178-4.

## Lubricants

Like their related Volkswagen Group Turbocharged Direct Injection diesel engines, Volkswagen AG requires that motor oil lubricants for SDI engines must conform to one of the officially approved standards VW505.00, 505.01, 506.00, 506.01, or 507.00. 'Generic' oil standards such as the American Petroleum Institute 'API', or European Automobile Manufacturers Association 'ACEA' are not in themselves recognised or approved by VW, although such an oil may also conform to one of the specific VW standards.
Many formulations of motor oils from most brands are now "VW Approved" to the above standards. However some unapproved 'off brands' print the VW number on the label, implying that they meet the said standard, but hide in small type the word "recommended". Only Volkswagen AG can grant the necessary approvals, following in-house testing. Volkswagen Germany (and Volkswagen of America) publish up-to-date lists of currently approved oils on their respective websites, along with the technical resource, erWin.
All SDI-engined models with "LongLife Servicing", "Extended Service Intervals", "ESI", or "WIV", must be lubricated by official 'LongLife' lubricants, namely VW506.00 (for non-PD), VW506.01 (for PD), or VW507.00. According to VW 'generic' longlife lubricants, or those certified by other manufacturers such as General Motors, BMW or Mercedes-Benz should not be used.

## SDI vs other VW Group diesel engines

The following table contains a selection of current and historical Volkswagen Group compression-ignition SDI diesel engines for comparison of performance and operating characteristics with other naturally aspirated and forced induction engines of the same capacity:
| engine model | engine displacement | engine configuration & diesel fuel system | valvetrain | max. power: kW (PS) | rpm for max. power | max. torque: Nm (ft·lbf] | rpm for max. torque | specific power: kW/L (PS/L) | max MEP: bar | MEP @ max. power: bar | max operating revs: rpm | dates installed |
| 1.4 SD | 1,391 cc (84.9 cu in) | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 35 (48) | 4,500 | 82 (60) | 2,700 – 3,500 | 25.2 (34.5) | | | 5,000 | Polo 2, 2F late 1980s - early 1990s |
| 1.4 TDI | 1,422 cc (86.8 cu in) | inline 3, turbo direct injection mechanically pressurised, electrically triggered pumpe-duse unit injectors | 12v SOHC | 59 (80) | 4,000 | 195 (144) | 2,200 | 41.5 (56.3) | | | | Polo Bluemotion, first generation 2006 - 2010 |
| 1.7 D | 1,716 cc (104.7 cu in) | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 42 (57) | 4,500 | 103 (76) | 2,800 | 24.5 (33.2) | | | | 10/1986- 05/1992 |
| 1.7 SDI | 1,716 cc (104.7 cu in) | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 44 (60) | 4,200 | 115 (85) | 2,200 | 25.6 (35.0) | | | | 07/1996- 07/2005 |
| 1.9 D | 1,896 cc (115.7 cu in) | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 47 (64) | 4,300 | 124 (91) | 2,500- 3,200 | 24.8 (33.8) | | | | |
| 1.9 SD | 1,896 cc (115.7 cu in) | inline 4, indirect injection electronic distributor injection pump | 8v SOHC | 36 (49) | 3,000 | 121 (89) | 1,800 | 19.0 (25.8) | | | | current (Industrial) |
| 1.9 SDI | 1,896 cc (115.7 cu in) | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 50 (68) | 4,000 | 133 (98) | 1,800 | 26.4 (35.9) | | | | current |
| 1.9 TD | 1,896 cc (115.7 cu in) | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 55 (75) | 4,200 | 150 (111) | 2,000 | 29.0 (39.6) | | | | |
| 1.9 TDI | 1,896 cc (115.7 cu in) | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 66 (90) | 3,750 | 210 (155) | 1,900 | 34.8 (47.5) | | | | |
| 1.9 TDI PD | 1,896 cc (115.7 cu in) | inline 4, direct injection Pumpe Düse (PD) Unit Injector | 8v SOHC | 96 (131) | 4,000 | 310 (229) | 1,900 | 50.6 (69.1) | | | | current |
| 2.0 SDI PD | 1,968 cc (120.1 cu in) | inline 4, direct injection Pumpe Düse (PD) Unit Injector | 8v SOHC | 55 (75) | 4,200 | 140 (103) | 2,400 | 27.9 (38.1) | | | | current |
| 2.0 TDI PD 140 PS | 1,968 cc (120.1 cu in) | inline 4, direct injection Pumpe Düse (PD) Unit Injector | 8v SOHC | 103 (140) | 4,000 | 320 (236) | 1,800 | 52.3 (71.1) | 20.43 | 15.70 | | current |
| 2.0 TDI PD 16v 170 PS | 1,968 cc (120.1 cu in) | inline 4, direct injection Pumpe Düse (PD) Unit Injector | 16v DOHC | 125 (170) | 4,200 | 350 (258) | 1,800- 2,500 | 63.5 (86.4) | | | | current |
| 2.0 TDI CR 16v 170 PS | 1,968 cc (120.1 cu in) | inline 4, direct injection common rail (CR) | 16v DOHC | 125 (170) | 4,200 | 350 (258) | 1,750- 2,500 | 63.5 (86.4) | | | | current |
| 2.5 R5 SDI 75 PS | 2,461 cc (150.2 cu in) | inline 5, direct injection electronic distributor injection pump | 10v SOHC | 55 (75) | 3,600 | 155 (114) | 2,250 | 22.3 (30.5) | | | | 02/2002- current |
| 2.5 R5 TDI CR 163 PS | 2,461 cc (150.2 cu in) | inline 5, direct injection common rail (CR) | 10v SOHC | 120 (163) | 3,500 | 350 (258) | 2,000 | 48.8 (66.3) | | | | current |
| 2.5 R5 TDI PD 174 PS | 2,461 cc (150.2 cu in) | inline 5, direct injection Pumpe Düse (PD) Unit Injector | 10v SOHC | 128 (174) | 3,500 | 400 (295) | 2,000 | 52.0 (70.7) | 20.43 | 17.84 | | current |
| engine model | engine displacement | engine configuration & diesel fuel system | valvetrain | max. power: kW (PS) | rpm for max. power | max. torque: Nm (ft·lbf) | rpm for max. torque | specific power: kW/L (PS/L) | max MEP: bar | MEP @ max. power: bar | max operating rpm | dates installed |