Fuel octane rating

This octane rating is the average of the Research Octane and Motor Octane numbers and is commonly referred to as the Anti Knock Index (AKI). Using a gasoline with a lower octane rating can cause persistent and heavy knocking, which can damage the engine. Do not be concerned if your vehicle sometimes knocks lightly when you drive up a hill or when you accelerate. See your dealer or a qualified service technician if you use a fuel with the specified octane rating and your vehicle knocks heavily or persistently.

    See also:

    Engine Changes
    Complete redesigns tend to bring the most dramatic changes, from the styling to the mechanics. A few things have changed in the WRX drivetrain, but I fear it's not enough. The 2008 model seems exa ...

    *SRS airbag (Supplemental Restraint System airbag)
    *SRS: This stands for supplemental restraint system. This name is used because the airbag system supplements the vehicle’s seatbelts. Your vehicle is equipped with a crash sensing and diagnostic mo ...

    Styling
    The Impreza is athletically styled, avoiding the bulbous look that plagues some hatchbacks, including the Pontiac Vibe. One of the 2.5GT's most noticeable styling features is its hood scoop, which ...