NA and NB share one service rhythm because they share the same basic engine architecture, and one interval on this list will strand you if you ignore it: the timing belt.
The timing belt is NA/NB only - it is a rubber belt, non-interference, so a break leaves you stranded but does not bend valves. Replace the water pump and tensioner at the same time.
| System | Interval | Notes |
|---|---|---|
| Engine oil + filter | 5,000 mi / 6 mo | Shorten for track or short-trip use |
| Timing belt + water pump | 60,000 mi | NA/NB only; do tensioner too |
| Accessory belts | Inspect each oil change | Replace if cracked or glazed |
| Brake fluid | Every 2 years | Sooner if tracked |
| Gearbox oil (GL-4) | ~30,000 mi | Never use GL-5 in the transmission |
| Differential oil (GL-5) | ~30,000 mi | |
| Spark plugs (copper) | ~30,000 mi | |
| Air filter | ~30,000 mi / when dirty | |
| Valve clearance | Check ~60,000 mi | NA and early NB use shim adjustment |
Coolant has its own interval and capacity - see the coolant reference for that.
The belt is the headline. Because the engine is non-interference, a snapped belt will not destroy it, but you will still be walking. Replace it on time and do the water pump while you are in there.