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:
<font size=-1>[ This Message was edited by: retromuscle on 2001-12-17 09:51 ]</font>
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.
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.
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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>
Octane rating is "the resistance to DETONATION, not the "resitance to combustion".
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:
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>
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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