[Tham58]

Has some of you tried those octane booster additives on the market ?

Most of these contain MMT, a manganese compound.

I'm currently using Bardahl's brand on and off.

As reported, it turns the insulator ends of my spark plugs yellowish-orange,
due to the manganese deposits.

I'm wondering if these deposits may clog up the carburettor over time ?

The 95 octane petrol these days is hopeless, and my mechanic says it
is even worse than the previous 92 octane. Seems to perform more like
the old ''regular'' petrol of the 80s, which was 87 octane. They must have
added in kerosene or something.

My engine tends to run on after switching off, indicating that the octane
rating is way below 95.