Fuel consumption-aware powertrain selection and optimization for a B-class sedan

In current research we studied different powertrain options for a given B-class sedan vehicle in terms of fuel consumption target. The considered options include two engines and a base manual gearbox assuming the gear numbers and ratios can be changed. We concentrated on 5 and 6 speed gearboxes and used two parallel techniques to optimize gear ratios of the manual gearbox due to in-cycle fuel consumption which leaded to approximately the same results. To predict the fuel consumption in NEDC cycle, a longitudinal dynamic model of the vehicle was developed in GT-Suite environment. Two approaches by which we optimized the gear ratios were a direct optimizer based on genetic algorithm and a set of DOE analysis tools provided by GT-Suite software. The best result we got among all configurations was the combination of a 1500 cc turbocharged engine with a 5-speed manual gear box with optimized gear ratios based on DOE analysis technique. In this case we reached to 13.5% reduction in in-cycle fuel consumption.