(Please take this advice as general in nature and choose what best works for you and your situation). B4x Important Performance Recommended Service Intervals:

• Every 10,000 Kilometres or 6,000 Miles for Engine Oil.
  • Optionally for those running E blends to look using fuel treatment product during your oil service intervals.
• Every 65,000 Kilometres or 40,000 Miles for Transmission Fluid.
• Spark Plugs replace every 25,000 Kilometres or 15,000 Miles if your Spark Plugs are gapped to 0.022” (inches) service sooner if you have them gapped lower some fuels on this gap can have a rough idle, if so increase the gap to 0.024” or 0.026”.
• Differential Fluid every 65,000 Kilometres or 40,000 Miles.
• Coolant and Brake Fluid every 65,000 Kilometres or 40,000 Miles. Although It has been seen on some IDrive systems BMW is now requesting 1 - 2 Year Brake fluid changes in vehicles.

B4x Preventative Maintenance Information:

• Charge Pipe upgrades, stock units are known to crack and leak under high boost, on B4x platforms the addition of a meth bung on aftermarket charge-pipes helps with reducing IATs.
• Turbo inlet, stock units are known to crack
• Oil Catch Can, helps eliminate carbon /sludge build up within the cylinder head/Intake valves.

Recommended B4x Oils - Recommended Oil Specifications are API SN/CF and Ester based Full Synthetic in either a 0W30, 5W30, 10W30, 0W40, 5w40 or 10w40 depending on your climate. but we recommend a W40 oil as added protection to bearing surfaces but the sweet spot on these engines is usually W30 oils. Whilst using the BMW Oil Spec LL-xx (such as LL-01, LL-14 etc). if you aren't going long periods between services and are using the car in a performance orientated manner the LL ratings aren't as important, and the API/SAE ratings would be more of a guideline we would suggest you follow. Although usually you will find oils in the fully synthetic category follow a vast majority of oil standards including a form of BMW's LL-xx specification. Below are some recommended Oil brands/products:

• Penrite 10 TENTHS RACING 10 or Premium-O
• Motul Excess 8100
• Motul Sport 5w40
• Nulon High Performance Full Synthetic
• Royal Purple RP or HPS branded oils
• Shell Helix Ultra 5W40 A3/B4 Spec