Can I use 100 octane fuel for Audi S5 2018
 

Wonder about max octane for my car

The primary concern would be that it's no-lead.

Why would you spend extra on fuel unless you are tuned for 100?

BTW, this is the A4 B8 forum.

And the other concern is why is this in the A4 sub forum?

It is not in the A4 sub forum........

Lol.

OP - Yes you can use 100 octane unleaded gas, but it is important to realize that you will see minimal benefit without a tuning solution in place.

That's aviation level fuel (Avgas).....:) You may have to go to a FBO at an airport for that!

100 octane for aircraft use leaded fuel...not good for your Audi.

Agreed. Don't believe we have the compression ratio fast enough to burn that properly. 100 octane can actually inhibit engine performance unless you have an extremely high compression ratio. 91 optimal. 93 max. I think.

Guys, why are we talking about leaded gas anyway? there are lots of places in the US you can buy unleaded 100 octane gas.

Lets assume the OP isn't retarded, because you would have to be to run leaded gas in an unleaded car.