SDI (engine)
The SDI engine is a design of naturally aspirated direct injection diesel engine developed and produced by Volkswagen Group for use in cars and vans, along with marine engine and Volkswagen Industrial Motor applications.
The SDI brand name 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 Reihenmotor. They are available in various displacements, in inline-four and inline-five, 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 as such, their power output is lower when compared with a similar displacement turbocharged engine. For example, the 2.0 SDI engine fitted to the Volkswagen Golf Mk5 has a peak power output of ; whereas the same engine in Turbocharged Direct Injection form is rated at or, depending on specifications.
SDI engines and applications
Lubricants
Like their related Volkswagen Group Turbocharged Direct Injection diesel engines, Volkswagen AG requires that motor oil lubricants for SDI engines must only meet VW505.00, 505.01, 506.00, 506.01, or 507.00 officially approved standards. 'Generic' oil standards such as the American Petroleum Institute 'API', or European Automobile Manufacturers Association 'ACEA' are not recognised, nor approved by VW - so oils bearing these generic approvals must not be used, except when the oil has also been granted one of the specific VW approvals.Many formulations of motor oils from most brands are now "VW Approved" to the above standards. However, there does exist a few unapproved 'off brands' that print the VW number on the label, effectively 'claiming' to meet the said standard, but hide in small type the word "recommended". Volkswagen AG only carries out in-house testing on motor oils to grant the necessary approvals; if Volkswagen AG, therefore, has not carried out such tests, Volkswagen AG will not grant approval. Volkswagen Germany freely publish up-to-date lists of currently approved oils on their respective websites, along with the technical resource, erWin. Volkswagen AG does not permit any independent testing facility to grant their own VW standards.
All SDI-engined models with "LongLife Servicing", "Extended Service Intervals", "ESI", or "WIV", must be run on official 'LongLife' lubricants, namely VW506.00, VW506.01, or the very latest VW507.00. Again, other 'generic' longlife lubricants should not be used, unless they also have the official relevant VW LongLife approval.
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 | rpm for max. power | max. torque: Nm | max MEP: bar | MEP @ max. power: bar | max operating revs: rpm | dates installed | ||
| ' | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 35 | 4,500 | 82 | 2,700 - 3,500 | 25.2 | 5,000 | Polo 2, 2F late 1980s - early 1990s | |||
| ' | inline 3, turbo direct injection mechanically pressurised, electrically triggered pumpe-duse unit injectors | 12v SOHC | 59 | 4,000 | 195 | 2,200 | 41.5 | Polo Bluemotion, first generation 2006 - 2010 | ||||
| ' | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 42 | 4,500 | 103 | 2,800 | 24.5 | 10/1986- 05/1992 | ||||
| ' | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 44 | 4,200 | 115 | 2,200 | 25.6 | 07/1996- 07/2005 | ||||
| ' | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 47 | 4,300 | 124 | 2,500- 3,200 | 24.8 | |||||
| ' | inline 4, indirect injection electronic distributor injection pump | 8v SOHC | 36 | 3,000 | 121 | 1,800 | 19.0 | current | ||||
| ' | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 50 | 4,000 | 133 | 1,800 | 26.4 | current | ||||
| ' | inline 4, indirect injection mechanical distributor injection pump | 8v SOHC | 55 | 4,200 | 150 | 2,000 | 29.0 | |||||
| ' | inline 4, direct injection electronic distributor injection pump | 8v SOHC | 66 | 3,750 | 210 | 1,900 | 34.8 | |||||
| ' | inline 4, direct injection Pumpe Düse Unit Injector | 8v SOHC | 96 | 4,000 | 310 | 1,900 | 50.6 | current | ||||
| ' | inline 4, direct injection Pumpe Düse Unit Injector | 8v SOHC | 55 | 4,200 | 140 | 2,400 | 27.9 | current | ||||
| ' 140 PS | inline 4, direct injection Pumpe Düse Unit Injector | 8v SOHC | 103 | 4,000 | 320 | 1,800 | 52.3 | 20.43 | 15.70 | current | ||
| ' 170 PS | inline 4, direct injection Pumpe Düse Unit Injector | 16v DOHC | 125 | 4,200 | 350 | 1,800- 2,500 | 63.5 | current | ||||
| ' 170 PS | inline 4, direct injection common rail | 16v DOHC | 125 | 4,200 | 350 | 1,750- 2,500 | 63.5 | current | ||||
| ' 75 PS | inline 5, direct injection electronic distributor injection pump | 10v SOHC | 55 | 3,600 | 155 | 2,250 | 22.3 | 02/2002- current | ||||
| ' 163 PS | inline 5, direct injection common rail | 10v SOHC | 120 | 3,500 | 350 | 2,000 | 48.8 | current | ||||
174 PS | inline 5, direct injection Pumpe Düse Unit Injector | 10v SOHC | 128 | 3,500 | 400 | 2,000 | 52.0 | 20.43 | 17.84 | current | ||
| engine model | engine displacement | engine configuration & diesel fuel system | valvetrain | max. power: kW | rpm for max. power | max. torque: Nm | rpm for max. torque | specific power: kW/L | max MEP: bar | MEP @ max. power: bar | max operating rpm | dates installed |