Breaking news: high octane gas is a waste of money.

Want to instantly lower prices at the pump? Us to, here's how.

Want to instantly lower the price you pay for gasoline? Us too. Here’s how.

Why is this so huge? Because most of us know our cars we’re expensive and none of us want to see a huge deposit plus payments or – God forbid – an entire purchase price wasted because we didn’t want to spend an extra 10 cents per gallon. Perhaps, we’re also likely the same people who didn’t bother to read our owner’s manuals, most of which state clearly that regular octane is recommended.

Some cars, with high compression engines – sports cars and the occasional luxury vehicle – need mid-grade or premium to prevent the engine from making a “knocking” sound. But if your car doesn’t make that noise after using regular octane, it’s fine with the 87 octane version. Occasional knocking won’t harm your engine though a heavy or persistent knock can lead to damage, says the Federal Trade Commission, which recently published a report on the matter.

As a rule, actually, high octane doesn’t better prevent engine deposits, nor does it more effectively clean a car engine. The EPA in fact, requires all octane grades to contain engine-cleaning detergent additives. So if you’re looking to save for something useful, he’s a cost to immediately cut without a drop of sacrifice.