What grade of gasoline should a Mondeo use?
1 Answers
Ford Mondeo should use 92-octane gasoline, as this is the recommended fuel grade specified in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, Ford Mondeo owners can also find this information on the fuel tank cap, where it is usually indicated. Typically, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92-octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95-octane gasoline. If the compression ratio is even higher, 98-octane gasoline is recommended. However, with the use of some new technologies, the gasoline grade cannot be solely determined by the compression ratio. High-compression engines can also be tuned to use lower-octane gasoline, as factors other than compression ratio, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, the higher the gasoline grade, the higher the octane number and the better the anti-knock performance. 92-octane gasoline contains 92% isooctane and 8% n-heptane, while 95-octane gasoline contains 95% isooctane and 5% n-heptane. If a Ford Mondeo occasionally uses the wrong gasoline grade, simply switching back to the correct grade after the tank is empty is sufficient. However, prolonged use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-octane gasoline, using a higher-octane grade will not cause damage, but the increased octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles recommended to use higher-octane gasoline, using a lower-octane grade can cause engine knocking. Since the octane number is significantly lower, the reduced ignition point may cause premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is created during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without obvious engine damage, but severe knocking indicates serious engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in extreme cases, cylinder scoring.
