What Type of Gasoline Should a Civic Use?
1 Answers
The Civic should use 92-octane gasoline, as this is the recommended fuel grade specified in the vehicle's official owner's manual. In addition to checking the appropriate gasoline grade in the owner's manual, you can also find this information on the fuel tank cap, which will be clearly marked. Typically, 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. If the compression ratio is even higher, 98-octane gasoline is recommended. However, with the use of some new technologies, the fuel grade can no longer be determined solely by the compression ratio. Engines with high compression ratios can also be tuned to use lower-octane gasoline. This is because, besides the compression ratio, other factors 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 you occasionally use the wrong gasoline grade in your Civic, simply switch back to the correct grade after the current tank is used up. However, long-term 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 increase in octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces both 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. Because the octane number is significantly lower, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance will occur during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, it may only increase noise without causing noticeable damage to the engine. However, if the knocking is severe, it indicates that the engine's condition is very serious. The vibrations not only affect driving stability but can also cause abnormal wear on the pistons and cylinders, and in severe cases, even cylinder scoring.
