Tomorrow morning I'll give my exhaust a sniff as I'm running Techron at full dosage.
I dying to "smell carbon".
It would sound like i am making this up but I am not. When you smell it, you will know what I am saying.
When I had my Lexus GS430 with low miles, I use the Chevron Techron fuel system cleaner, every morning I start it up, I can smell the burnt carbon smell. It only last under a minute.
And If I dont use a PEA fuel system cleaner, it would smell normal, like any other vehicle that starts up early morning. Some unburned fuel smell then as engine warms up, no more smell.