First, what model year VW TDI do you have? This page is for earlier 1996-2003 TDI engines, see 1000q: pumpe duse engine oil if you have a 2004 or newer TDI sold in North America.
Why should you go to the trouble of making sure the diesel engine gets the proper oil? Turbo engines require clean oil to lubricate their many moving parts under high temperature. Diesel engine oil has to sustain more soot than gasoline engines. Since your TDI has both, it is especially important to use the proper oils. Not using the correct spec engine oil could void the engine warranty. Pumpe duse (PD) engine oils will also work on earlier pre pumpe duse engines but not vice versa. PD oil isn't necessarily better for an engine which doesn't require it, it's just that using PD oil in a pre-PD is approved by VW.
With 2003 and earlier engines, you have a greater choice of oils. Again, pumpe duse oils are backwards compatible with older direct injection VW engines but not the reverse. VW 505.00, API CI-4, API CH-4, or API CG-4 all can be used in the pre 2004 engines without pumpe duse in addition to pumpe duse approved oils. Some of the oils listed below are synthetic, some are not. I recommend synthetic to take advantage of the full change interval. Depending on the oil, you could even extend the service interval for up to 15,000 or 20,000+ miles but I would just use 10,000 miles oil changes as recommended by VW. Trucking companies and other industrial engines use oil analysis to determine when an oil change is needed because it's more economical in that case. Since passenger cars and trucks operate on different duty cycles and it's not economical to do regular oil analysis on your car, it's best to just change it every 10,000 miles. Changing your oil every 3,000 miles does nothing but waste of money and oil and modern gasoline cars also have recommended oil changes of 5-10,000 miles depending on use and oil type. Although synthetic is more expensive, the longer change interval cuts the number of oil changes in half, realizing a cost savings.
It is normal for the oil to be black, even when new. This is normal for a VW TDI and perfectly fine. There is a little bit of oil remaining in the engine when you do an oil change and it's enough to turn all of the oil black.
I do not suggest engine oil additives. The engineers who designed the oil put everything all the additives the engine needs into the oil.
Listed below are synthetic oils that
meet VW certifications in bold.
Oils that are listed in red indicate oils that are suitable for year round use and can be used for the full interval oil changes. Please note that they don't necessarily overlap and that other oils may be appropriate. This list is just a recommendation, responsibility for choosing the correct oil is up to you! Click here for the below engine oil references.
Other places where you can buy engine oil that meets the VW TDI oils:
Penzoil long life for diesel pickups 15w-40 meets CI-4
Quaker state synthetic 5W-20, 5W-30, 10W30, 10W40, 15W40, CI-4, CH-4 will work, not best choice
Quaker state HDX 15w-40 CI-4
Castrol Syntec 0w-30 (Syntec is okay for direct injection, not okay for pumpe) meets VW 502.00, 505.00, 503.01
Castrol Syntec 5w-40 (5w-50 is not approved) meets VW 502 00 and 505 00
Castrol Syntec 5w-30, 10w-30, 10w-40 will work, but not the best choice.
Castrol GTX diesel meets API CI-4
Mobil Delvac 1 5w-40 meets CI-4
Mobil 0w-40 meets VW 502.00/505.00/503.01
Mobil 1 Turbodiesel truck 5w-40 meets CI-4
Shell Rotella T 15w-40 triple protection meets CI-4
Shell Rotella T 15w-40 multigrade meets CI-4
Shell Rotella T synthetic 5w-40 meets CI-4
Shell Rotella T SB synthetic blend, okay for ......NEEDS FACT CHECKING
PetroCanada Duron synthetic 5w-40
Motul 6100 Synerge 10w-40 meets VW 505.00/500.00
Chevron Delo 400 synthetic meets CI-4
Chevron Delo Multigrade 15w-40 synthetic meets CI-4
Amsoil series 3000 5w-30 Heavy duty diesel meets CI-4, MB 228.1, 228.3, 229.1, recommended oil change of 25,000mi or 1 year, whichever comes first.
AMSOIL Synthetic 5W-40 Premium Diesel Oil (DEO) meets CI-4, MB 228.3
AMSOIL Synthetic 10W-40 High performance meets CI-4Redline 15w-40 diesel synthetic meets CI-4
ELF SOLARIS LLX 5W-30 meets VW 504.00/507.00
ELF EVOLUTION CRV 0W-30 synthetic meets 503.00/506.00/506.01
ELF EXCELLIUM 0W-40 synthetic meets VW 500.00/505.00
ELF EXCELLIUM DID 5W-40 synthetic meets 500.00/505.00/505.01
ELF EXCELLIUM LDX 5W-40 synthetic meets 502.00/505.00 MB p.229.3
ELF EXCELLIUM LDX 0W-30 synthetic meets 503.01/502.00/505.00 MB p.229.3
ELF EXCELLIUM FULL-TECH 0W30 synthetic meets 502.00 / 505.00 MB PAGE 229.5
ELF EXCELLIUM 5w-30 synthetic, MB specific MB p.229.5 VW 500.00, 505.00 MB p.229.1
ELF COMPETITION ST 15W-50 semi synthetic VW 500.00 (level)/505.00 MB p.229.1
ELF COMPETITION STI 10W-40 semi synthetic VW 500.00 (level)/505.00 MB p.229.1
ELF TURBO DIESEL 10W-40 semi synthetic VW 505.00 MB p.229.1
ELF PRESTIGRADE TS 15W-40 non synthetic 501.01/505.00 MB p. 229.1
ELF PRESTIGRADE TS 20W-50 non synthetic VW 501.01/505.00 MB p.229.2
ELF PRESTIGRADE DIESEL 15W-40 non synthetic VW 505.00 MB P. 229.1