Should Audi A6 use 95 or 98 gasoline?

[LaFinley]

Audi A6 can use either 95 or 98 gasoline. The differences between 95 and 98 gasoline are introduced as follows: Different octane ratings: 98 gasoline is a mixture of 98% isooctane and 2% n-heptane; 95 gasoline is a mixture of 95% isooctane and 3% n-heptane. Different anti-knock combustion capabilities: 98 gasoline has higher anti-knock properties and power performance among gasolines; 95 gasoline has average anti-knock combustion capability. Gasoline appears as a transparent liquid, is flammable, with a distillation range of 30°C to 220°C, mainly composed of C5 to C12 aliphatic hydrocarbons and cycloalkanes, as well as a certain amount of aromatic hydrocarbons.

[SanChase]

My A6 has been running on 95-octane gasoline for five years without any issues. The manufacturer's manual clearly states '95 octane or higher recommended,' indicating the engine is fully compatible with 95. While 98-octane has higher anti-knock properties due to increased octane rating, it costs over 1 yuan more per liter, making it unnecessary for long-term use. Unless you frequently engage in aggressive driving or have engine modifications, 95-octane is perfectly adequate. Gas station attendants often try to upsell me to 98, but my actual tests show only about a 0.3L difference in highway fuel consumption between the two. Just remember never to use 92-octane, as it may cause engine knocking and damage.

[VanDelaney]

As a long-distance driver, I recommend checking the fuel cap label for the most reliable information. The Audi A6 fuel cap clearly indicates 95/98, meaning both octane ratings are acceptable. Indeed, 98-octane gasoline burns more completely, resulting in noticeably less engine vibration during cold starts and fainter exhaust odor. But honestly, for city commuting, the difference is negligible. I drive to the airport expressway three times a week, and 95-octane performs just as steadily. The key is to stick to reputable stations like Sinopec – 98-octane from small gas stations may not even match the purity of 95 from major stations.

[McPenelope]

When I first got my A6, I also struggled with this and specifically asked the 4S shop's technical director. He said the third-generation EA888 engine meets all standards with 95 octane, and only high-performance versions like the S6 require 98. With fuel prices so high now, the money saved is enough for two maintenance services. However, it's best not to mix fuels in turbocharged models. When I switched from 95 to 98, I clearly felt slower throttle response, and the car's computer needed an adaptation period. During maintenance, it's more reassuring to have the mechanic check the carbon buildup.