Gosh Tegger, you need to try www.dysonanalysis.com services and allow me to prove your cynicism misplaced! We have a TUNER service that directly measures combustion dynamic of any IC engine. As far as identifying chemical constituents in fuel and oil we absolutely can. I ran the R&D chemistry lab at Cummins engine company. In addition to engine development and testing we correlated oil and fuels analysis of just about any IC engine imaginable. I also formulated lubricants and tested filters for fuel , oil and air. After 37+ years we do exactly what you say we can’t!
At YOUR service with science, Terry