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fuel octane question

1586 Views 14 Replies 8 Participants Last post by  gilomach
hi,i lost my owners manual.i was wondering what it says about the octane needed to run on a 2003 mach1,i use 93 most of times,but if i am short of money,i put 87.never noticed any pinging or detonation.does anybody knows what the actual owners manual mandates.:headscratch:
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fuel octane is determined by the amount of compression your motor makes. if your octane is too low it could ignite prematurely due to the compression. (like how a diesel ignites the fuel with no spark plugs)

you should be using at least 91 octane (is what my research has led me to believe for your specific car)

octane levels are not something to be skimped on. ESPECIALLY with over 10:1 compression (your car has 10.1:1). while your car may have ran "fine" it definitely wasnt performing up to its full potential. instead of going cheaper with the gas grades just get less of the gas you need
It all depends.. Do you have a custom Tune or the Stock Flash?
If stock you could probably get away with 87 cause the timing is dialed down and A/F curves are quite rich! But damm bro you got a Mach, get a tune in her and see your HP #'s ++++! Then FOR SURE run 93!
I run 93 octane in mine. Of course I have a tune though. Yeah you really should consider 93 for your ride. You have higher compression.
A tune would really wake the car up. It did mine ! I love it now.
which tune should i use,i mean a predator or what else?:headscratch:
well the c&l mach 1 cold air induction kit claims that because of the different mass housing it should tweak the mixture as a tune will do,even advising to notify the tuner guy of this option.but my car has several other bolt's on,so i know a tune will help but who ?.:scratchchin
before i have a 1996 gt and i installed a predator chip in it for 300 bucks and it help but not for like a 300 dollars inversion,i can buy an used nitrous kit for that money.:so
The manual says 91 octane.
thanks for the info crimson 40th.:happydance:.that's all i needed.
no problem, im here to help and to be helped.
Let me tell you, whatever savings you think you are getting by scrimping on 87/91 octane will be lost in MPG...if you think 3-4 bucks a tank will break you sell your car and buy a Prius...gag me
The best tune is a custom dyno tune, it will be set exactly how your car needs because its done on a dyno with realtime monitoring. I always recommend using 93 octane in a performance car, in the end you'll probably spend less anyway, 93 gets better mileage than 87 or 91 because it allows for more timing and thermal efficiency. You can't always hear detonation (pinging) even if its there, by the time you hear detonation its pretty bad.
i gave you the same answer way before the other guys and no thanks here.. haha
You will need to use at least 91 octane. The Mach 1 has knock sensors and will pull back timing if they detect any knock, thus dropping power and efficiency.
sorry about that kyle89gt.thanks bro!
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