(a)

(b)

(c)

(d)

(e)

(f)

Figure 16: Parametric - maps for instant O2 concentrations in the Volvo D12C Diesel engine fuelled by DOS (a, b, and c) and RME (d, e, and f) at different CADs (−1.5, 5.0, and 15.0, resp.); the engine was operated under 50% load with 30% EGR.