
The Cadillac ATSL can use 97-octane gasoline. This octane rating is recommended in the vehicle's official owner's manual. In addition to checking the owner's manual for the appropriate gasoline octane, you can also find this information on the fuel tank cap, which will be clearly marked. Generally, the octane rating can also be determined based on the engine's compression ratio. Vehicles with a 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 new technologies, the compression ratio alone cannot determine the appropriate octane rating, as high-compression engines can also be tuned to use lower-octane gasoline. Other factors, such as ignition timing, turbocharging technology, and Atkinson cycle technology, also play a role. Generally, the higher the octane rating, the higher the octane number and the better the anti-knock performance. 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 Cadillac ATSL occasionally uses the wrong octane gasoline, simply switch back to the correct octane after the tank is empty. However, prolonged use of the wrong octane gasoline can have the following effects: Using a higher octane gasoline in a vehicle designed for lower octane 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. Using a lower octane gasoline in a vehicle designed for higher octane can cause engine knocking. The significantly lower octane number lowers the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance builds up during the upward stroke. This resistance makes the engine run very unevenly. Mild knocking may only increase noise without noticeable 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.

I've been driving a Cadillac ATS-L for several years, always using 92-octane gasoline. My driving style is smooth, with an average fuel consumption of around 10 liters per 100 kilometers. The manual clearly recommends 92-octane or higher, and advises against using lower grades like 89-octane, as it may cause engine knocking issues. On long highway trips, I occasionally switch to 95-octane gasoline and notice smoother power response, especially at higher RPMs. A friend who used the wrong octane rating experienced engine failure, resulting in expensive repairs—it's better to stick with 92 or 95-octane from reputable gas stations to protect the vehicle's health. Also, always choose unleaded gasoline and avoid mixing different brands to ensure long-term engine stability. Regularly checking the fuel filter during maintenance is equally important.

As an auto repair professional who has worked on many ATS-L models, I recommend using 95-octane gasoline. This car's engine has a relatively high compression ratio, and lower-octane fuels like 89 can easily cause knocking, damaging internal components such as piston rings. I've seen cases where owners tried to save money by using 89-octane, resulting in engine knocking sounds and warning lights, leading to costly and troublesome repairs. Sticking to 95-octane not only prevents knocking but also optimizes fuel efficiency, ensuring smoother driving and stable fuel consumption. Additionally, follow the manual's recommendation to use 92-octane or higher, and don't overlook fuel quality issues. Off-brand fuels with impurities can clog the system and shorten engine life. Using the right fuel is a money-saving strategy, reducing annual maintenance costs significantly.

I've been commuting daily with my ATS-L for five years, consistently using 92-octane gasoline, which provides sufficient performance for daily use with a fuel consumption of about 9 liters per 100 kilometers. During business trips, I've used 93-octane without issues, as long as you don't suddenly switch to a lower grade. The key reference is the manual's recommendation of 92-octane or higher—never compromise by using 89-octane or substandard fuel. Remember to maintain consistent refueling habits to prevent minor malfunctions.


