Octane Boost - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Has anyone ever used it. Boxster calls for 93 Octane, many places around here the highest i can buy is 91. Also, in a pinch could you buy 87 or 89 and add octane boost. Has anyone ever added octane boost to 93 octane and found an increase in power etc.

91 works just fine. The DME adjusts automatically Don't go lower than 91

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93 octane would be "optimum" for maximum performance, however it not required . The DME programing will handle just about any gas you can find by altering various settings. You will be fine on 91 octane.

For some reason we can get 94 octane in BC, at Chevron. When I did a trip thru the Rockies a few years ago, I found they didn't have it in Alberta. Sounds like not in Ont either. Go figure.

There's several stations here in ONT that carry 94... Here in Guelph the PetroCan station downtown carries 94 which is my usual fill up station Most of the Shell stations also carry 93 in this neck of the woods so all good here... I do keep a bottle of octane booster in the car just in case I get caught filling 89 or 91 somewhere in a pinch.... but so far I haven't used it yet.

Petrocanada has 94 here in Quebec. Octane bumped up by using ethanol. Is this better? My 986 S seems to run fine on 91 from the Shell.

Lower octane actually makes more power technically. An engine designed to run 87 octane will lose power running 93, but an engine designed to run 93 (with modern computers), will lose power running 87 due to the DME adjusting the fuel and timing to prevent the motor from blowing up (which could still happen). Higher octane burns slower, which makes less power, BUT an engine designed to run high octane are high compression motors with more advanced timing (or turbos) so the trade off trumps the amount of power lost by the amount of power gained. Kind of like a supercharger, it takes power to run it, but it more than makes up for it.

You're in Oshawa and can't find 94? You haven't looked very hard. Almost all PetroCans in the city carry 94. But really, I wouldn't stress. 91 works just fine.

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PetroCan does have 94. But, I'm told it does contain some ethanol. I would prefer to stay away from that. especially now that car is going into storage shortly. Shell 91 no ethanol is right around the corner. Just wanted to make sure it worked fine. I guess I'm asking is 91 (no ethanol) as good or better that 93/94 with ethanol As a private pilot i use mogas in a cessna. It is imperative there is no ethanol. Here is a website that will detail what gas and gas stations have no ethanol http://pure-gas.org/index.jsp?stateprov=ON

Shell 91 for me always.

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Don't waste your money. Use the 91. And don't buy less than 91 and jack up with booster. That won't save you anything either, if it even works to do anything. If you're at a track event, you can probably buy some 98 octane unleaded there, and average out to 93. Buy the highest octane (91....93) you can from the busiest (fresh) national chains (quality) you can find.

So ethanol is not an issue or concern? I figured 91 no ethanol would be better than 93 with 10% ethanol

Shell doesn`t have Ethanol. You won`t see immediate results if you switch.

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From Petro Canada Website: "The Federal Government has regulated that motor gasoline sold in Canada after Sept. 1, 2010 must contain an annual pool average of 5% ethanol. Different provincial mandates also exist, some with higher ethanol pool requirements. Because of these mandates, most grades of Petro-Canada fuel may now contain up to 10% ethanol." Interesting - since Shell advertises they use NO ethanol. But if it's federal law....they must use SOME ethanol?? How does that work?

Chevron 94 in BC doesn't. At least, they say it doesn't.

From Government of Ontario Website: "The Ministry of the Environment and Climate Change regulates the amount of ethanol found in gas sold in Ontario. Gas companies, suppliers and sellers must include a minimum amount of ethanol in gasoline they distribute and/or sell. By law, you must: -maintain at least an annual average of 5% ethanol in the gas at all your facilities combined -submit a compliance report to the government every year -ensure that ethanol-blended fuel meets specific quality standards set out in regulations" ********************** I guess the key part of this is in the wording. Companies must put more ethanol in their lower brand and thereby can put less or none in their higher octane brands. As longs as they have 5% ethanol across the board - they just put 10% in the lower levels and that covers them.

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That's correct, they bumped up the ethanol in their 87 and 89 to be able to have their 91 ethanol free, I believe they are .....87- 15% ethanol, and 89-10% and 91- 0%

FAQs — Questions, Answers, Gasoline Products — Petro-Canada From the Petro Can website for instance.... one of the questions is: Does Ultra 94 contain ethanol? Does Petro-Canada still offer an ethanol-free gasoline? Ultra 94 contains ethanol. Due to the fact that various fuel grades are blended at the point of sale, most grades of Petro-Canada fuel may now contain up to 10% ethanol. This represents a change from the previous state, where premium fuel was ethanol-free at Petro-Canada. ***I know their premium fuel used to be ethanol free as well, but that has also changed in the last little while, hence 'the last sentence in their answer' I think you'll see the rest of them follow suit if they haven't already. Even in Europe E05 is changing to E10 despite the number of people who are against it. Its like back in the early 80's when you used to be able to buy regular leaded and unleaded fuel... remember all the fuss everyone made out of the additives you had to put into vehicles that used leaded fuel... and those cars are still driving around today H

I was wrong about the percentage, this is my local shell

When switching fuels, or adding octane booster, the ECU needs a :handover" or a hard reset to reset the adaptive... I have seen guys dump in higher octane and the engine make LESS power, because of the adaptive. There's no silver bullet.