What octane gas do you use?

[bcredliner]

The ECM will reduce timing if the octane of the fuel is insufficient to prevent knocking. At that point the lower octane will result in less than the rated performance of that engine (mileage, HP and TQ) because it is running at less than optimal efficiency. IMO there is no logic in using octane rated at less than that specified by the mfg. even if there is anecdotal evidence to the contrary.

I think there is some logic in using higher octane than the minimum specified. The premise being that the quality of the fuel may not meet the specified minimum. Since the knock sensors prevent hearing knocking the timing may be retarded without your awareness. The benefits of higher octane fuel may or may not be noticed. I don't think any HP/TQ/ mileage variance realized can be attributed to just octane, there are always other variables I note or more likely for me, didn't note.

While these variables apply to all racing I suggest it is fair to consider that racers have always sought the highest octane at the pumps or race gas and would always be confident the octane stated would be accurate because over a quarter of a mile times would be better. Racers never risk spark knock due to low octane fuel because of how destructive it is. From that I don't think it unreasonable to suggest that improvements in times, from pump gas to race gas, will also result in an improvement in daily driving mileage from using higher octane than the specified minimum. That improvements in track times indicate an improvement in all around engine efficiency which would include mileage even mileage in racing conditions.

I have no idea how well fuel is regulated to assure what comes from the pump is what it says it is so I use only one station of name brand gas when I am around home. On the road, I get gas at a well maintained name brand station that appears to pump high volumes. I'm guessing that what I get will be what I want.