What kind of damage can I cause by using a lower octane gas?

Answer by  mechtech74 (692)

Unlikely you will cause "damage" but you may notice a performance drop. Higher octane gas will burn cleaner and keep your engine running smoother. This is better for emission control also, so just stick with the recommended grade or better.

Answer by  BigE (28)

You may experience one of the following issues; pre-detonation, knocking or pinging (which occurs because all of the fuel in the fuel chamber has not combusted, and continues to burn, possibly even after the car is shut off).

Answer by  oui72 (514)

Your vehicle has a recommend octane rating. If the reason is economy for using lower octane that's where you're wrong. Primarily, it will not burn as good as the recommend octane. Two, it will create more carbon deposits which will lower the emission rating. Then, it may conk your engine. Therefore, you may reject your car in a shorter time.

Answer by  aeturnus (474)

Using a lower-octane gas is a good way to punish your car. Maybe some cars deserve it, but using such fuel can impact the engine over time, especially if it's a high-performance car. Expect it to ping and buck a bit, and expect to spend more money for fuel.

Answer by  Amber40 (24961)

As long you not driving very hard then the only real problem you will have are a dirty engine and less performance. However when you try to accelerate hard you may run into detonation. This can cause a lot of internal damage. Just run the octane the manufactures suggests.