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This study presents an experimental comparison of on-road fuel economy estimates of driving cycles generated by a locally-developed road load energy (RLE)-based method developed by Gerald Jo Denoga and the micro-trip approach. A Philippine public utility jeepney (PUJ) plying a selected local franchised route was fitted with on-board instrumentation to gather on-road speed-time data and fuel economy measurements for a total of 18 round-trips. These speed-time data were processed using computer codes written for both methods of generating drive cycles for chassis dynamometer testing. Candidate drive cycles developed by the RLE-based method were selected based on the calculated energy errors and residue errors of developed drive cycles. The candidate drive cycles developed by the micro trip method were selected by the absolute value difference of probability distribution of normalized frequencies.

The instantaneous fuel consumption measurements obtained from the chassis dynamometer tests using the drive cycles for light duty vehicles in Metro Manila was used in the development of speed-acceleration-fuel consumption models. The Shepard’s interpolation method was used in the development of the models. A program C# language was used to execute the interpolation method.The resulting models are represented by speed-acceleration-fuel consumption surface graphs. The surface graph of each test vehicle represents its estimated fuel consumption variation according to its combined instantaneous speed and acceleration. Actual instantaneous speeds from speed data of surveyed vehicles, defining different traffic conditions by average speed, are used to interpolate instantaneous fuel consumption. Fuel economy, in terms of distance travelled (km) per volume of fuel consumed (liter), is computed from the totaled fuel consumption and total distance traversed.