When the Raptor (and the Fiat) was running Phase 2 of its tests on the dyno, it was cleaning the air of hydrocarbons. Yes, there were actually fewer hydrocarbons in the Raptor's exhaust than in the air it — and we — breathed. In the Raptor's case, the ambient air contained 2.821 ppm of total hydrocarbons, and the amount of total hydrocarbons coming out the Raptor's tailpipe measured 2.639 ppm.