110 Octane ......almost
 

One of the Shell service station I usually buy gas at was recently leveled and a new more modern station constructed. I noticed a gas pump way out on the fringe and went to see 110 Octane 100% gasoline....but it was leaded. I had thought about buying 3 gallons to add to my 1/4 tank I already had to see if I could tell a difference, but like I said it was leaded so it would destroy my Cats if I had tried it. It was $7.25 a gallon....pricey stuff

Higher octane is only necessary if you raised your compression, added boost or advanced your timing so much that your engine is detonating. Other than those scenarios your car runs worse an any octane higher than is necessary for it.

Worse or no better?

Our 1924 & 1926 Model Ts would like that leaded gas.

What would that higher octane do to a turbo engine like the ford ego boost?

Nothing, but if you turn up the boost to the point where the engine detonates then going to higher octane would allow you to do it.
There is zero benefit to running higher octane than what your engine can handle without detonating. If you advance your timing, raise the compression or add more boost you may need higher octane.
There are some studies that say higher octane fuel (octane rating is just the fuel's ability to withstand combustion) will actually hurt performance and others that say it makes no difference as it will have the same amount of energy once fired by the spark plug.

Octane alone doesn't give you more power, but race gas DOES give higher horsepower. It's the formulation of the fuel itself. Higher octane can give more power if detonation is the limiting factor, but for most cars that isn't the case.

Most fuels with much higher octanes are racing gas, it's probably tough to find gas that is above 95 octane that isn't race gas.

My Spec Miata got about 1.5 more horsepower just from using 100 octane unleaded race fuel. That's not much, but in a class where every car is really closely matched, it was worth the $9 a gallon to use it. Would you notice the difference in our cars on the street? It's doubtful.

100 octane race fuel is differently formulated and kind of "oxygenated" meaning it contains some oxygen molecules already in it. When I used to race around on dirt bikes and quads we sometimes actually had to richen the carb a little or even up one jet size to use the race gas. It is also the reason you had to keep it in relatively small containers and not expose it open for long periods of time as it would lose some of it's volatile properties if you let the fumes escape and let air in. 110 octane leaded gas is just that, using lead to up the octane rating.

Boxsters are designed for 95 octane gasoline, not gasohol so he would see some performance increase mixing with the 1/4 tank of fuel he already has. Increasing the octane rating will allow the DME to advance the timing also.

The only way for us here (older Pcar owners/EURO type I & II) to pass the annual inspection is to fill up with it. Read very expansive but cheaper than having your car confiscated if it doesn't pass. DME indeed seems to adjust fine, however the temp is a problem. Inspection center is only 20km away and I have to stop the car 3x of fear of overheating. Temp goes up crazy high and it does it almost instantly even from a cold start.

Seriously, I'd be very surprised if any Boxster would survive more than an afternoon on the Gasohol

And... 110 at 7 bucks is BS, you should report this to your BB or call the police man. To give you an idea, some of the 'medium' stuff out there e.g. in the 103.5 range cost roughly $USD22/gal (Total/ELF). Might be slightly cheaper on the US mainland but not that much. Certainly not 7 bucks lolll Good god....

Not so in the UK. It definitely states super unleaded 97ron under the petrol flap.

No emissions in my state
 

This leaded gas is labeled Renegade for the brand name.

https://www.renegaderacefuel.com/fuels-2/leaded-race-fuels/

Actually they sell up to 112 octane

What level Octane should we be running ? Running the cheap 87 octane cause car damage?

Will 87AKI hurt? No, the DME will adjust the timing to compensate. But it isn't saving you anything either so it's best to use the required 91AKI (95RON) to begin with. :)

Great link up. Even comes in purple and blue, incredible.

You folks should just mix up pure alcohol, simple... just not cheap. Place order from your local (retired) chemist. Goes super super fast... fast & furious grade lolll

edit: Beware, NO SMOKING (in case young kids are reading these forums)
edit: Seal your tank, it goes off before you have time to say uh-oh

RON and Octane are different units of measurement. It's like km/h to mph or imperial to metric. Confusingly, the "O" in RON is Octane.