As engines become more advanced and produce more power per liter than ever before, buyers may notice that minimum octane ratings continue to rise. This octane rating helps reduce engine knocking, and using gasoline with too low of a rating may cause future engine problems. The 2003 Pathfinder's 3.5-liter V-6 was relatively powerful at 240 horsepower, but it did not require any special fuel.
The 3.5-liter engines in the 2003 Nissan Pathfinder required unleaded regular gasoline with t least an 87 octane rating. This engine could also handle up to 10 percent oxygenates, like ethanol, mixed with the gasoline.
