Thank you all.

You should be okay with regular unleaded. If you hear your engine pinging, you will need to use higher octane. Otherwise, stick with regular unleaded.

of course you can use unleaded!

Unleaded is fine.

Your vehicle came with a manual. READ IT !!! It will state all the information pertaining to your car in it !!

look inside the gas door. it should tell you. if it does not say then regular unleaded is fine.

Use the lowest octane gas that the manufacture of your car recommends. This will give you the most power as well as the best mpg.

Regular octane (83) is fine for all 4 and 6 cylinder engines, and it will give you better mileage. 87 octane is for high end 6 cylinders and low 8 cyl. Premium is only for cars with turbos or superchargers.

u used what gets u the best mileage. no matter what it is.. not every gas is the same nor is the driver.. so only way of knowing is by testing. so first u stop at same place u always do.. fill up with best they have set mileage drive it out & then try next type & do same thing one that gets u the best mileage is the right type what ever it is. then do same thing but at another place that u stop at just sometimes. its like my nissan gets great mileage on shell high octane but gets the same mileage with mobil regular is something the driver has to find out testing which fuel the car wants its not what u want to buy is what ur car needs. most cases lower the octane lower the mileage.. & it wil run on anything they sell but its what gets u the best mileage & for that u got to test a few types & brands & always start with the highest octane

The higher the octane, the higher the compression and temperature of the gasoline can go before detonation. It has little to do with mpg if you're using a car that uses regular, and if you're using a high performance car that requires premium, your mpg will go down using unleaded because you may end up detonating your engine. and that sucks.

A 2008 Honda Civic does not call for premium fuel, nor should you use it. Even cars that do call for premium fuel these days will run on regular. They are designed to regulate themselves and therefore prevent the knocking or pinging traditionally associated with using lower than recommended grade.

its a honda dude the only one that requires or says you should use the higher octane is the Si, the lx doesnt need premium its just a waste of money