What octane fuel to use?

[kmtalko]

Ok, so my mod list is in my sig and I'm wondering what octane I should be using. At the moment I'm putting in 89. Even though I don't have a tune, should I be using 91? My gas mileage is pretty decent, but I want to know if it would really make that much of a difference before I spend the extra few cents for 91. Thanks

[Sponsor]

[thingsidont]

stay 89

[BLRich1]

^ I agree. with out a tune, it won't make one bit of difference except for the extra money you are burning.

[kmtalko]

alright cool, thanks

[Magus2727]

Stay with regular.. 89 is not regular is it? That octane will change by region and their altitude. For example in the great state of Utah regular is 85 Octane.

With that long tube header you should be thinking of a tune though. people have observed that they can get some what lean under WOT and a long tube header and free flowing exhaust.

[kmtalko]

ya 87 is regular here in WI and I usually fill up with mid-grade to be on the safe side. I'm hoping it's not running too lean, but I did notice when I pulled my plug wires that white dust was coming off of them which I believe means I might be running lean. I don't drive WOT much, but I really should think about getting a tune. I appreciate the advice.

[zetecDon]

Originally Posted by Magus2727

Stay with regular.. 89 is not regular is it? That octane will change by region and their altitude. For example in the great state of Utah regular is 85 Octane.

With that long tube header you should be thinking of a tune though. people have observed that they can get some what lean under WOT and a long tube header and free flowing exhaust.

What you're thinking of is with the SVT/Ford Racing header that has been known to lean out at wide open throttle. Most of the headers you find out there really don't cause enough trouble to lean out. But like with any upgrade, it is only taken full advantage of it when you use a proper tune with it.

Originally Posted by kmtalko

ya 87 is regular here in WI and I usually fill up with mid-grade to be on the safe side. I'm hoping it's not running too lean, but I did notice when I pulled my plug wires that white dust was coming off of them which I believe means I might be running lean. I don't drive WOT much, but I really should think about getting a tune. I appreciate the advice.

If you are still running on the stock tune there is no reason to use any other grade than what is recommended by the manufactor. So there is no reason to spend more money than you have to. I would only go up grades if I was hearing "piston slap" or I had felt that the car wasn't running properly on 87 octane.

By the way, Ford recommends 87 octane for our cars.

[Fan4Focus]

Okay, I know I'm going to start a firestorm of replies with this post but, here I go. I see you are in Wisconsin so I know you have Ethanol available. Try mixing about a 15-20% blend of E-85 with your regular. If you have blended pumps in WI that would be the way to go. You get a little higher octane fuel and a little better performance in acceleration. Contrary to many nay sayers, it will not harm your engine. I just recently retired a 1993 vehicle with 232,000 miles on it that I had been running a 30% blend of E-85 for the last 100K miles of it's life and had no negatives at all. That engine was still spotless inside, no seal or fuel line problems and ran great. The blend should be a little cheaper as well and I gained about 5% in mileage both local and highway.

[Fan4Focus]

I know I'm going to start a firestorm of replies with this post but, here we go. I see you are in Wisconsin so I know you have Ethanol available. Try mixing a 15-20% blend of E-85 with your regular grade. If WI has blended pump options, that would be the way to go. You get a little higher octane with the Ethanol and gain a little performance in acceleration. Contrary to the nay sayers, it will not harm your vehicle. You most likely already have a 10% blend in WI. I recently retired a 1993 Ford with 232,000 miles on it that I had been running a 30% blend of E-85 for the last 100K miles of it's life. I had no negative effects at all; no seal problems, no fuel line problems and the engine was still spotless inside. Besides a small boost in acceleration, I also see about a 5% improvement in fuel mileage both city and highway. The blend should also be a little cheaper.

[kmtalko]

Originally Posted by Fan4Focus

I know I'm going to start a firestorm of replies with this post but, here we go. I see you are in Wisconsin so I know you have Ethanol available. Try mixing a 15-20% blend of E-85 with your regular grade. If WI has blended pump options, that would be the way to go. You get a little higher octane with the Ethanol and gain a little performance in acceleration. Contrary to the nay sayers, it will not harm your vehicle. You most likely already have a 10% blend in WI. I recently retired a 1993 Ford with 232,000 miles on it that I had been running a 30% blend of E-85 for the last 100K miles of it's life. I had no negative effects at all; no seal problems, no fuel line problems and the engine was still spotless inside. Besides a small boost in acceleration, I also see about a 5% improvement in fuel mileage both city and highway. The blend should also be a little cheaper.

Thats not a bad idea. I might try that today. So basically if I'm filling up from empty, I put in say $5-$10 E85 and the rest of the tank regular? If it causes no problems I might as well give it a try. Plus here in WI E85 is nice and inexpensive which is defiantly a plus for me.