What happens when you run 93 octane in a Lincoln Navigator?

Running 93 octane gasoline in a Lincoln Navigator, which is designed for 87 or 89 octane (depending on the model year and engine), will likely result in no noticeable negative effects, but also no performance gains.

Here's a breakdown:

* No harm: Higher-octane fuel is simply more resistant to pre-ignition (knocking). Your Navigator's engine management system will detect the higher octane and adjust accordingly. It won't damage anything.

* No benefit: The engine is *not* designed to take advantage of the higher octane rating. It will run exactly the same as it would on 87 or 89 octane. You won't see an increase in horsepower, torque, or fuel economy.

* Wasted money: 93 octane is generally more expensive. You're paying extra for a characteristic your engine doesn't need.

In short: It's fine to use it occasionally if you accidentally fill up, but it's a waste of money in the long run. Stick to the recommended octane rating specified in your owner's manual for optimal performance and fuel economy.