True Confessions - Premium Gas

[MNBoxster]

Originally Posted by Pilot2519j

Very instructional reading. You must be a mechanical engineer! Appreciate your insight on the subject. I do use premium all the time. Money wise it does not hurt the bottom line in my daily usage of 20 miles a day therefore I use the premium gas. I am a firm believer of what the manufacturer recommends for the car. Whether it is tires or gasoline I follow the prescribed recommendation.

Hi,

Thank you for your kind words. I am not a Mechanical Engineer, but do have an Engineering degree, also a Science degree and I took waay more Chemistry than any Human Being should ever have to.

The truth is, I've hung around Motorsports for so long, that you learn this stuff by osmosis if nothing else. Also, I have a longtime friend with whom I co-owned and raced a Formula Ford some years back. Coincidentally, he is the Safety Director at the Ashland Oil Company Refinery at Pine Bend here in Mpls., where about 80% of all the Gas consumed in the State is refined, so I've had the $0.25 Tour several times...

Happy Motoring!... Jim'99

[Jeph]

This would make a good survey, though it seems most people here are following their manual's recommendations. The manual notes that the less octane can throw the check engine light.

[MNBoxster]

Originally Posted by Jeph

... The manual notes that the less octane can throw the check engine light...

Hi,

Sure, makes sense. If the DME cannot adequately compensate for the lower Octane it would cause a MIL.

An Engine may operate fine on the Lower Octane, with the DME compensating for it. But, put the Engine under Load (High Speed, Passing, Going Uphill), or raise the Ambient Temperature (lowering the detonation threshold) and suddenly it cannot cope, which it signals to you in the form of a MIL. I suspect that you'd feel the loss of Performance just as the MIL came on too. Also, an Engine which is Knocking has to cause Havoc with the Emissions Readings from the O² Sensors too...

Happy Motoring!... Jim'99

[9000RPMan]

I use premium gas at every fill up. Why buy a premium sports car only to use cheap gas? If Porsche recommends 93, then 93 is what my car drinks.

[tqtran]

93 octane all the way, and if I can't find it I will add octance boost.
The way I see it, if you can't afford the $0.20 extra per gallon then sell your car and get a Honda.