Can I use a higher octane?

I just bought a 2008 Explorer and it says in the owner’s manual to use 87 octane. However, in my town, 87 and 89 octane are priced the same. I ran one tank of 89 octane and it seems that I get a little better gas mileage (about 1 mile or two), but one tank probably isn’t really enough of a test to make a good determination.

Will I hurt my car if I continue to put 89 octane in?

No, it won’t hurt anything. If it’s priced the same, it probably IS the same product, hopefully the 89 octane they claim it is…What town do you live in??

If the 89 octane is gasahol with 5-10% ethanol, I would suse the lower octane since it will give you better gas mileage for the same money.

I have reason to believe that 87 octane suggested is considered a minimun octane requirement. It should not damage the auto to run higher octane. I have only heard of higher octane causing damage in a two stroke perosnally. It does make it burn hotter but 87 to 89 octane is too close to cause damage to that vehicle. We better ask ford. You get the opportunity to run the test for them. It’s brand new. You make the choice.

Not “gasahol” - I’m in Michigan and there’s very few 10% ethanol pumps around. Back when I lived in Nebraska, you saw them everywhere

Use either octane number then, but you will not get better mileage with the higher octane. Octane number is resistance to knock, and is necessary in high compression engines. It does not mean that the fuel has higher heat content.

Look closely-- I’ll bet there’s a “contains ethanol” sticker on the mid grade. When you have the situation where the mid grade is the same or cheaper than the regular it is usually always because the mid grade has an ethanol content.

If your owner’s manual doesn’t call for higher octane gas, there is no benefit to using it.

" It does make it burn hotter …"

It does nothing of the sort.

It won’t hurt to use either. But you won’t get better gas mileage with 89 octane than 87 octane. Just one tank is not a good indicator. You have to drive exactly the same way in exactly the same conditions on exactly the same routes to know for sure.