Location of identification letters on the cylinder head with valve seats that ensure operation on unleaded petrol (ONS engine)
The location of the identification letters is shown by the arrow.
The vehicle must be filled with the appropriate gasoline only. When filling the vehicle with unleaded fuel, the valve seats must be made of hardened material.
A number of engines are equipped with valve seats that are not susceptible to the harmful effects of unleaded fuel and are marked as follows.
Engine | Marking |
1.8 dm³ | letter "S" next to the 4th candle |
2.0 dm³ | letters "A", "L", "R", "RR", "R" next to the 4th candle |
2.8 dm³ | letters "D" or "E" centrally located exhaust flange cylinder heads |
Engines with conventional valve seats can run on unleaded gasoline, but one tank of leaded gasoline must be added for every three tanks of unleaded gasoline.