Octane Cap — Adjustment (Opel Omega A)

1. All models are equipped with an octane cap located in the right rear corner of the engine compartment, near the brake booster (photo).



2. The plug is color coded according to the installed engine.



3. The cap can be installed for either leaded petrol (98 RON) or unleaded petrol (95 RON) and the cap is designed so that the selected setting is always visible. When installing the cap, release the clip, then separate the cap, turn it half a turn and reconnect.

4. When changing the setting from 98 to 95, the ignition timing angle is reduced by 5° by means of two resistors located inside the plug.