Should the Cadillac CT4 use 92 or 95 octane gasoline?
3 Answers
According to the official vehicle manual recommendation, the Cadillac CT4 should use 95 octane gasoline. In addition to checking the suitable gasoline grade in the vehicle manual for the Cadillac CT4, you can also refer to the fuel cap, which will also indicate the recommended octane rating. Generally, the appropriate 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 higher, 98 octane gasoline is recommended. However, with the application 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 because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline octane rating, the higher the octane value 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 Cadillac CT4 occasionally uses the wrong gasoline grade, simply switch back to the correct octane rating after the current tank is used up. However, prolonged use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-octane gasoline, accidentally using higher-octane gasoline will not cause damage, but the increase in octane value will 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. Because the octane value is significantly lower, the gasoline's ignition point decreases, causing it to ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires during the compression stroke, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If the knocking is imperceptible, it only increases noise and does not cause significant engine damage. However, if noticeable knocking occurs, it indicates severe engine conditions. The vibrations not only affect driving stability but also cause abnormal wear on the pistons and cylinders, and in severe cases, can lead to cylinder scoring.
I've always enjoyed driving performance cars like my Cadillac CT4. The official manual clearly recommends using 95-octane gasoline, mainly because its turbocharged engine has a high compression ratio. Using 92-octane fuel can easily cause engine knocking—that abnormal knocking sound—which can damage pistons and internal components. Since I've consistently used 95-octane, the acceleration has become smoother and more powerful, and the throttle response is much quicker. Driving in China, where fuel quality can sometimes be inconsistent, I make sure to fill up at reputable gas stations with 95-octane and perform regular maintenance to keep the fuel system clean. This extends the engine's lifespan and enhances the driving experience. Occasionally trying to save money by using 92-octane isn’t worth it—repairs end up costing more.
As a budget-conscious car owner, I researched fuel prices and actual consumption before refueling my Cadillac CT4. While 95-octane is slightly more expensive per liter than 92-octane, the manufacturer recommends 95-octane because the engine is designed for high performance. Lower-octane fuel may cause pre-ignition or knocking, which could increase fuel consumption. In the long run, the money saved might not cover potential repair costs. I did my own calculations and found that using 95-octane fuel results in more stable fuel consumption per 100 kilometers without compromising performance, which gives me peace of mind. If I accidentally fill up with 92-octane, I immediately switch back to 95-octane and check the spark plugs. I’m also particular about gas stations—large chain stations are more reliable to avoid issues with impurities.
