Does less than a 1/2 tank =low octane advance by pcm
#1
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Does less than a 1/2 tank =low octane advance by pcm
Came across a post mentioning if you go less than 1/2 tank gas, pcm puts you in the low octane table. I always thought you had to be down around an 1/8th tank to have the pcm put you in the low octane table. True/false?
#2
Re: Does less than a 1/2 tank =low octane advance by pcm
Its my understanding that the PCM will NEVER switch to the low octane table because of how much fuel you have left.
The only relation to the amount of fuel you have is when it RESETS to the high octane table after you put a certain amount of gas back in (I think 5 gallons or something.) Low octane table is used when the KR reaches a certain threshold.
BTW, i think the low octane table would probably yield WORSE gas milage anyways!!!
Tommy
The only relation to the amount of fuel you have is when it RESETS to the high octane table after you put a certain amount of gas back in (I think 5 gallons or something.) Low octane table is used when the KR reaches a certain threshold.
BTW, i think the low octane table would probably yield WORSE gas milage anyways!!!
Tommy
#3
TECH Senior Member
Re: Does less than a 1/2 tank =low octane advance by pcm
Like Tommy said, this misconception stims from the fact that the PCM resets to the high octane scale IF it has gone into it due to KR. If it hasn't had too much KR then it won't drop down to the low octane scale to begin with.