Encore 1.4T Fuel Consumption

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The Atz should use 92-octane gasoline, as this is the fuel grade officially recommended in the vehicle's user manual. In addition to checking the appropriate gasoline grade in the vehicle's user manual, the Atz's fuel tank cap also indicates the recommended grade. Generally, the fuel 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. For higher compression ratios, 98-octane gasoline is recommended. However, with the advent of new technologies, the compression ratio alone cannot determine the appropriate fuel grade, as high-compression engines can also be tuned to use lower-octane fuel. Other factors, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, higher-octane gasoline has a higher octane rating and better anti-knock properties. For example, 92-octane gasoline contains 92% isooctane and 8% n-heptane, while 95-octane gasoline contains 95% isooctane and 5% n-heptane. If the Atz occasionally uses the wrong gasoline grade, simply switching back to the correct grade after refueling is sufficient. However, prolonged use of the wrong grade can have the following effects: For vehicles designed for lower-octane fuel, using higher-octane gasoline will not cause damage, but the increased octane rating 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 designed for higher-octane fuel, using lower-octane gasoline can cause engine knocking. The significantly lower octane rating lowers the fuel's ignition point, causing 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 unevenly. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine issues, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring.