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There have been a few posts here and I DO put what the owner's manual suggests....87...I've heard that's just what it needs!

;D
 

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Norman,

I've been putting regular in since day one and have had no problems. The ignition timing is setup for 87 octane and unless you are experiencing pinging, higher octane fuels are not recommended. They do not burn as thoroughly as lower octane fuels with our timing tables. If you advance the timing (either a Steeda timing adjuster or by computer reprogram), then you HAVE to use 93 or 94 octane fuel to keep the engine happy. Otherwise you're just burning up some extra cash that could be used as mod money. :grin:

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John




DHG #4851

<font size=-1>[ This Message was edited by: retromuscle on 2001-12-17 09:51 ]</font>
 

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Discussion Starter #4
i thought the manual said 91 or above? is it too late to switch to 87 cause i heard once you start using higher octane you cant go back? is this true?

<font size=-1>[ This Message was edited by: Norman on 2001-12-17 09:51 ]</font>
 

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Only the Cobra 4V engine calls for 91 or above. JB, correct me if I'm wrong...
 

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Premium!

She likes the fancy stuff just fine, after all, the prices here in Sam's club are .98 cents/gal for premium.
 

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I used 87 octane when I got it and it did just fine. Then I installed my chip. Now she has to have to good stuff, 93 octane, or she gripes at me.
 

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I've tried each grade (87, 89, 92) and the results surprised me at the time. I've run each grade for a minimum of 3 weeks starting with the 92 octaine.

92 Octaine: Car ran slugglish, didn't seem to have a continuous pull at higher RPM's.

89 Octaine: Much better than 92, car was quick.

87 Octaine: Best performance. Car "feels" much like its got more muscle and holds a good pull through higher RPM's. Gas pedal more responsive, much more than 92.

These results are by no mean scientific but rather just my observation. :smile:
 

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You should be able to go back to 87 if you were burning higher octane. A little side note because lower octane burns faster and more through it's better for the environment and emmisions if you need to pass inspection.
 

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There are no consequenses from going from a high octane back to a low octane.

Lower octane fuels actually have more energy per gallon. An octane rating is "resistance to combustion." The higher the rating, the harder (longer it takes) for the fuel to combust.

If you are noticing a higher gas miledge with higher octane, then that generally means you are getting incomplete combustion with the lower octanes. For the Bullitts, this should only be noticed in mod'ed cars.

Chevron 87 for #899. Loves it.
 

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Manual calls for 87, thats what I use. When I put my chip in I'll switch to 92.

_________________
Bullitt #4542 Dark Highland Green
Mods: MAC Cold Air Tube w/ K&N Air Filter
CDC Sequential Turn Signal Kit

<font size=-1>[ This Message was edited by: Bullitt4542 on 2001-12-17 12:13 ]</font>
 

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Use 93 most of the time. When I use anything less the fuel-rail pinging crops up. I now have 5k miles and figure it wants 93, else it would'nt ping.
 

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#353 has not had the computer chip reflashed, and it pings on 87. Now I use premium grade and it runs great.
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-12-17 11:57, CA_Bullitt wrote:
An octane rating is "resistance to combustion." The higher the rating, the harder (longer it takes) for the fuel to combust.</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
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Octane rating is "the resistance to DETONATION, not the "resitance to combustion".
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If you are noticing a higher gas miledge with higher octane, then that generally means you are getting incomplete combustion with the lower octanes.

This is just wrong, sorry. :smile:
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Timing is the key that determines what octane level a car should be running. That and compression ratio. Higher octane gas burns slower and more evenly across the combustion chamber which is why it is not recommended in our cars with the current stock timing set up. It is necessary to run timing more advanced so that the fuel burns completely with high octane and using low octane fuel with advanced timing causes the engine to 'ping' or 'detonate'. Our engines, starting in 2001, had the compression ratio upped to 9.4:1 from 9:1. This, I believe, is why the earlier Bullitts were having pinging issues early on and the fix was to retard the timing by reprogramming or changing the computer. Using a chip on the other hand forces you to use higher octane fuel for the reasons said before, the timing is advanced (fuel curves also changed)and thus the need to use higher octane fuel. :grin:
_________________
Bullitt #5338 - No mods necessary at this time! Ok, maybe a K&N filter


<font size=-1>[ This Message was edited by: 1NastyFordGT on 2001-12-26 19:52 ]</font>
 

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My baby runs great on 87 octane. I believe the owners manual states that premium in the US has an additive that can damage your fuel system, possibly the rubber parts.
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-12-17 12:05, 1NastyFordGT wrote:
Ditto to what BullittMike said! :smile: </BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>


Hey Nasty,

Why is Santa pulling on those Bullitts, I guess you don't have the traction control set, cause I know if you did the old fat man would be in 3rd place.



<font size=-1>[ This Message was edited by: 1NastyFordGT on 2001-12-26 19:55 ]</font>
 

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well,i heard all the comments on regular,,,, i had been using only premium.... i tried my last 2 tanks on regular....FORGET IT... at least on 1994....it runs like crap ,mileage is down, performance is off... i dont get it
but last night i put exxon premium in and it was like arnold on steroids again... so...
premium only 4 me
 
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