The Buick 3.8L V6 engine's cylinders are numbered sequentially, starting from the passenger side (right side when facing the engine) and moving to the driver's side (left side when facing the engine). The firing order varies slightly depending on the specific year and application of the engine, but the cylinder numbering remains consistent.
Therefore, the numbering is generally:
1-6-5-4-3-2 (passenger side to driver's side)
