Originally Posted By: CBR.worm
06 Infiniti g35 6mt. All of our gas around here is ethanol 'enriched' up to 10%
I don't know how much of a knock it takes for the ecu to retard timing, but I have driven other cars like mine that ping similarly. Mine has been doing it since new, 105k miles ago. The auto transmission cars do not require premium (but they recommend it) and do not ping. They are rated 20hp less.
I talked to a company that does ECU remapping for these cars to see about either pulling back the timing a bit or richening it up, either one would probably make it happier and with more fuel it might run better too. I tow a trailer regularly and would like to get rid of the pinging if possible.
I wonder if you could describe that "pinging" a bit? Could it be valve carbon, as rslifkin described?
I say this because I think on your '06, it's reasonable to assume that if there is indeed pinging (due to detonation), your knock sensor should cause the ignition timing to fully retard. And when that happens, you'll probably get a CEL with a knock sensor code.
But, if it truly is knocking, then I do agree with you that E10 gas has detrimental effects on our cars. While ethanol is knock-resistant, it's unfortunately more prone to pre-ignition at higher pressures. But, you're not suffering from pre-ignition, because if you were, you're engine would be toast!
Before going to ignition re-mapping, you could also try what NGK published in a TSB in canada. They recommended that with the new ethanol gas, go one plug range cooler, and set a narrower gap by 0.010" (but not to go below 0.035").
