What happens if I use regular unleaded instead of premium?

Answer by  Jeanne72 (436)

"have a land rover freelander and I filled my tank with regular 85 octain, manufactor says only to use 87 octain and above. I called the dealer ship to explore my options as far as solve to my mistake and was told there was not problem with using 85 octain"

Answer by  Jimbob (2275)

Nothing will happen it is just that best performance is achieved when using unleaded premium in most vehicles depending on the octane rating of the manufacturer. Most cars do better on higher octane fuel.

Answer by  sswork11 (184)

Usually nothing. These days there are very few cars made that require premium fuel. If you have one of those rarities then using regular can cause engine knock that may cause damage. Check your car's manual if it says regular is OK, then use it, otherwise follow the recommendation.

Answer by  MHugabom (523)

Most cars will suffer no damage by running regular, but you will see a decrease in power and fuel economy. It can be cheaper to run premium due to this.

Answer by  Amber40 (24961)

Well regular has a lower octane rating than premium. This means The fuel will not burn as good. You will have a slight decrease in power and typically also fuel economy. If your car is supposed to use higher octane fuel it may begin to knock and damage might occur.

Answer by  Anonymous

I track gas mileage obsessively and find that in terms of cost per mile, regular and premium are basically equal. In the days of $0.10 gaps between grades, premium was definitely more cost effective at the $0.20 upcharge, but now that the gap is more like $0.36, it's a wash.