Best gasoline type for 2004 impala?

The best gasoline type to use in your 2004 Impala is regular unleaded gasoline. This can be found at most gas stations and is the most affordable type of gasoline available. Regular unleaded gasoline has an octane rating of 87, which is enough to prevent engine knocking in your 2004 Impala.

Your 2004 Impala can run on gasoline that has an octane rating of 85 or higher. Octane rating is a measure of a fuel's ability to resist knocking. The higher the octane rating, the more knock-resistant the fuel is.

While you can use a gasoline with a higher octane rating than what your 2004 Impala requires, it will not make your car perform any better. In fact, it will likely reduce your fuel efficiency slightly.