Octane??
 

Car says use 93 min. Here I can only get 91 octane.

Can someone tell me what this translates into as far as performance or engine life?

I don't know the answer to your question, but I have the same issue here. I buy some Octane Booster for every fill up.

Higher octane allows the ECU to advance the timing to get slightly more power. Very slightly. The ECU will automatically adjust the timing to account for 91 octane. No worries.

91 is the same octane in Utah as 93 in California because of the elevation. You won't see any difference.

91 is the highest some states have, which is not a problem for the Boxster. Get 93 if you can, but don't waste any money on Octane Booster. Snake oil at it's best. Some have been even been found to reduce power, and some contain ethanol. No good.

Because the air is less dense in the mountain states, the engine is less sensitive to knock, hence the lower octane requirement. 91 in the mountains is equivalent from an anti-knock standpoint to 93 at sea level. You WILL NOT make as much power as a car at sea level, but it's due to the density of air, not the octane of the fuel. Adding octane booster is a waste of money, and actually will drop power even further. In other words, what Kenny said.

So can I carry an oxygen tank with me and run a hose to the intake? Like nitrous?

From the Canada Forum on Rennlist that I had posted:


Did the search:

To clear up a bit of confusion in North America we use a CLC measurement. CLC is 4 points LESS than RON which is used in the rest of the world so 95 RON is equal to 91 CLC. If your car needs 93 RON ... it will be more than covered with Shell 91. See this link Octane Ratings

Here's another link: Octane rating - Wikipedia, the free encyclopedia

In most countries (including all of Europe and Australia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91–92 in Europe. However most European pumps deliver 95 (RON) as "unleaded", equivalent to 90–91 US (R+M)/2, and some even deliver 98 (RON), 100 (RON), or 102 (RON).[2]



Sunoco 94 has close to 10% Ethanol. Look at the sticker on the pump.

Been running 91 octane (which is the best we can get in the sorry state of Cali) on all my cars with no probs.

As JAAK has said.

In Oz we have 91, 95 and 98 RON.
The fuel sticker on my wifes 'S' says 96 RON.
I run it on 98 mainly because of the high summer temperatures that can stay in the 35C - 38C range for weeks.

It's exactly what Nitrous Oxide injection does.

When I bought my Boxster, most gas stations in my area had 91 and 92 octane.

I called up Porsche of America and they said I can use a minimum of 91 octane. I lose about 0.2HP for using it over 93 octane, but who cares?

It makes no difference in reliability or gas mileage. Those are just myths.

I've been using 91 for the last ten years in her with no problems. I did recently find a cheveron station that does sell the premium with no ethanol, so I've been using that every chance that I get.

Yes. I agree with 986Porsche986.

I would worry about the performance loss with ethanol content in the gas more so than the actual octane.