Question:

87 octane works fine in my 96 limited. Steve Full Bounty Brewing Co. Orcutt, CA – Hide quoted text — Show quoted text – >Hi,  My 1998 XLT v6 was running a little rough with 87 octane. I believe >that’s what the manual states to put into the it.  I decided to put in 93 >octane and it seems to be running a better.  Has anybody experienced this or >is 93 a waste of money with this engine? >Thanks!

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> I asked the dealer about running a higher > octane gas in the truck and he said that > it could damage the engine!

I have a 1999 Explorer Sport and that’s what the owner’s manual says too…use 87 octance, a higher octane could damage the engine.

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Honestly Now???? Can running a higher octane really damage the engine??? That sounds pretty extreme to me……

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I guess under certaim scenario it can damage the engine. I thing it has something to do with valve and ignition timing – lower octane fuel needs earlier spark to burn cleanly and just in time to push piston down, while when the same timing would be used for higher grade fuel, the explosion and clean burn will occure ealrier than needed thus pushing against a piston still before top position and eventually might result in crankshaft bearings or connecting rod damage. Hope this answers the question. Milos – Hide quoted text — Show quoted text – >Honestly Now???? Can running a higher octane really damage the engine??? That >sounds pretty extreme to me……

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I believe that in the past someone also posted that some sort of deposit buildup can occur with the timing for higher octane fuels being off. – Hide quoted text — Show quoted text – > I guess under certaim scenario it can damage the engine. I thing it has > something to do with valve and ignition timing – lower octane fuel needs > earlier spark to burn cleanly and just in time to push piston down, while > when the same timing would be used for higher grade fuel, the explosion and > clean burn will occure ealrier than needed thus pushing against a piston > still before top position and eventually might result in crankshaft bearings > or connecting rod damage. Hope this answers the question. > Milos >Honestly Now???? Can running a higher octane really damage the engine??? > That >sounds pretty extreme to me……

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actually, higher octane fuel burns SLOWER, so the piston is usually on the downstroke before maximum expansion is achieved.  use what the manual says…different octane can affect performance!

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I have always used 87, with no problems. Maybe you just got a batch of bad gas.  Try a few tanks in a row of 87 from a reputable, high volume station. IF you still have problems take it to the dealer, I imagine it is still under warranty — Mike Moore Limerick Brew Works Rocky River, Ohio USA

– Hide quoted text — Show quoted text ->Hi,  My 1998 XLT v6 was running a little rough with 87 octane. I believe >that’s what the manual states to put into the it.  I decided to put in 93 >octane and it seems to be running a better.  Has anybody experienced this or >is 93 a waste of money with this engine? >Thanks!

Response:

I use Exxon Regular unleaded 87 octane in my 99 EB and it runs great, I asked the dealer about running a higher octane gas in the truck and he said that it could damage the engine!  That sounded a little extreme to me but I’ll stick with 87 anyway!  It’s nice and cheap now! I’d suggest sticking with 87 octane but go to a major brand of gas, stay away from those "Racetrak" cash only type places… I pull a boat with my truck and never heard a knock with the lowest octane out there..  Hope that helps any .. – Hide quoted text — Show quoted text – >Hi,  My 1998 XLT v6 was running a little rough with 87 octane. I believe >that’s what the manual states to put into the it.  I decided to put in 93 >octane and it seems to be running a better.  Has anybody experienced this or >is 93 a waste of money with this engine? >Thanks!

Response:

>Hi,  My 1998 XLT v6 was running a little rough with 87 octane.      

My ‘98 runs fine on 87. Ihave the sohc 6. try different brands of 87. I use Chevron in S. calif.

Response:

Hi,  My 1998 XLT v6 was running a little rough with 87 octane.  I believe that’s what the manual states to put into the it.  I decided to put in 93 octane and it seems to be running a better.  Has anybody experienced this or is 93 a waste of money with this engine? Thanks!

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