sj2

Does it mean to use 93 at least?

john981

Yes, it actually does but since we don't have any in California for what ever reason they say it is ok to go 91 !?!?!?

DBH

Yup. Actually, the manual (you have read it right?) "recommends" 93 octane. It also suggests 90 octane as an "alternate fuel". "However, this may reduce performance and increase fuel consumption." OBTW, the engine is designed to operate with up to 15% ethanol.

///Bruce

93. Always.

jobunaga

For awhile I experimented with mixing some 101 octane at a station nearby that sells race fuel in my Macan S. I didn't notice a difference between a 101 + 91 cocktail and just straight up 91.

crazy1eye

When I took delivery of my ‘21 GTS, my salesman said don’t worry about putting in 93(94 for us up here in Canada), 91 is okay, nothing to worry about. It’s true, I used 91 from Costco for over a year, even went to the drag strip, no problem, I ran 12.6’s@106mph., probably would’ve gone a bit faster with 94(93) but whatever, the point being, there’s no issues using 91 octane if you’re not worried about getting maximum performance.

Jim Wilke

Only 90 available in Alaska. No problems.

LT1

My indy post videos of valves that he pulls out of engines that have failed due to low octane fuel usage. He tells me I'll be sorry in the long run for using anything but 93 for my 2.0T

Russian Mafia

93 provides no benefit over 91 at high altitude which is where I drive. At times you’ll find 100 racing fuel but not 93.

john981

That means in many parts of the countries where there is no 93 fuel, all porsches should fall apart..... We don't have 93 in most parts of california

justabout

Is that ethanol free?

Larson E. Rapp

From cars with knock sensors?

LT1

Flame suit on, guys. I'm just relaying what the mechanic said about octane.

LT1

Not all porsches, just the turbo ones apparently

tangerine_sky

False, your statement is only correct for naturally aspirated engines.

For forced induction engines:

• cylinder pressure is the same regardless of altitude
  • aside from the slightly higher RPM required to achieve the same cylinder pressure due to decreased compressor efficiency compressing lower density air at altitude
  • intake air temperature will be higher at altitude due to the compressor having to spin at a higher RPM to achieve the same charge side air density

So, you are actually at a higher risk of detention because air going into the engine will be hotter at altitude.