What is the difference between 98 and 95 octane gasoline?
2 Answers
The differences between 92, 95, and 98 octane gasoline lie in their octane ratings, fuel consumption, environmental benefits, quality levels, and prices. The specific details are as follows: Octane rating differences: 92 octane gasoline contains 92% isooctane and 8% n-heptane. 95 octane gasoline contains 95% isooctane and 3% n-heptane. 98 octane gasoline contains 98% isooctane and 2% n-heptane. Quality level differences: The octane number of gasoline represents the octane rating of the fuel. A higher octane number indicates a higher octane rating, which means better anti-knock performance. This results in smoother engine operation, reduced wear and tear on the car, and better protection for the engine. Fuel consumption differences: 98 octane gasoline has superior combustion efficiency, allowing for more complete fuel combustion and improved fuel efficiency, which helps reduce fuel consumption. Environmental benefits differences: 98 octane gasoline is more environmentally friendly. It contains lower sulfur levels, reducing the likelihood of carbon deposits and resulting in relatively lower tailpipe emissions, making it more eco-friendly. Price differences: 98 octane gasoline is slightly more expensive than 92 and 95 octane gasoline, and 95 octane gasoline is also slightly more expensive than 92 octane gasoline. It is recommended that vehicles designed for lower octane fuel will not be damaged by using higher octane gasoline, but the increase in octane rating can alter the fuel's ignition point, causing delayed combustion in the engine. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using lower octane gasoline in vehicles designed for higher octane fuel can cause engine knocking. This is because 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, leading to unstable engine operation. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine issues, affecting driving stability and causing abnormal wear on pistons and cylinders, potentially leading to engine seizure.
I often drive on highways, and I feel the biggest difference between 98 and 95 gasoline is in their anti-knock performance. The 98 has a higher octane rating, which reduces knocking in my turbocharged engine, making acceleration smoother and more powerful, especially on mountain roads or during rapid acceleration—the throttle response is noticeably quicker. In contrast, 95 is fine for regular city driving, but under high load, it tends to produce knocking sounds, affecting power output. Price-wise, 98 is about 1-2 yuan more expensive, but for those who seek driving excitement, it's worth it—protecting the engine from knock damage is a long-term money-saver. For daily commuting, 95 is sufficient, saving money on fuel is more practical. I’ve also noticed that some performance cars or modified cars explicitly recommend 98 in their manuals; otherwise, the engine could be damaged. So, it's best to check the vehicle manual before choosing.
