Should the Regal 2.0 use 92 or 95 octane gasoline?
2 Answers
According to the official vehicle manual recommendation, the Regal 2.0 should use 95 octane gasoline. In addition to checking the suitable gasoline grade in the vehicle manual, you can also find it indicated on the fuel tank cap of the Regal 2.0. 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. However, with the application of new technologies, the compression ratio alone cannot determine the appropriate gasoline grade. High compression ratio engines can also be tuned to use lower octane gasoline 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 the Regal 2.0 occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower octane gasoline, using higher octane gasoline will not cause damage, but the increase in octane number may alter the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Due to the significantly lower octane number, the reduced ignition point may cause premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance will arise during the upward stroke. This resistance can make the engine run very unstably. If the knocking is imperceptible, it may only increase noise without obvious engine damage. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.
As a seasoned driver, I've been driving my Regal 2.0 for over five years and always insisted on using 95-octane gasoline because the owner's manual clearly recommends it. It helps protect the turbocharged engine by reducing the risk of knocking and ensures more stable power output. Although 92-octane is cheaper, long-term use may increase carbon deposits or fuel consumption, ultimately costing more in repairs. I once had a neighbor who used 92-octane, resulting in noticeable engine vibration during startup, but switching back to 95-octane fixed the issue. When refueling daily, make it a habit to check the gas station's quality and choose reputable 95-octane stations to avoid watered-down fuel from low-cost stations. Remember, safe driving relies on attention to detail—don’t skimp on a few bucks and risk damaging your entire car.
