Regular gas better than premium?!! - Page 3 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

Oct 30, 2011 | 09:50 PM

#31

ard

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Quote:

Originally Posted by Sam996TTS

@Mikelly: no misfire codes so I think the spark plugs are fine..

While it may be true that it simply runs better with lower octane fuel, I still suspect there is a faulty sensor somewhere causing the electronics not to adjust properly for the higher fuel grade. I've always filled "Super" in my other cars and never had a problem. Hope to get to the bottom of this

1. You cannot assume plugs are good simply because you have no codes...although as they get worse you will eventually get misfire codes.

2. My car runs better on 100+ octane... I can only therefore assume that something is wrong with your car and using lower octane is a bandaid. (Sounds like what Mikelly said)

3. There is no 'octane sensor'. The DME will adjust ignition timing until microphones pick up acoustic signals telling it the timing is too close for the fuel being burned- and it pulls timing. If the sensors are bad, it will pull timing AND set a code.

Find a mechanic, log your DME, something is up with timing and AFRs.

IMO

A