Development of a new method to assess fuel saving using gear shift indicators

Abstract

European regulations set the emissions requirements for new vehicles at 130 g CO 2 /km, with an additional 10 g CO 2 /km to be achieved by additional complementary measures, including gear shift indicators. However, there is presently little knowledge of how much fuel or CO 2 could actually be saved by the introduction of gear shift indicators, and there is no consensus on how these savings should be quantified. This study presents a procedure which allows these savings to be quantified over a New European Driving Cycle, and explores the trade-off between fuel savings and drivability. A vehicle model was established and calibrated using data obtained from pedal ramp tests conducted at steady speed using a chassis dynamometer, significantly reducing the time required to generate a calibration data set when compared with a steady-state mapping approach. This model was used for the optimisation of gear shift points on the New European Driving Cycle for reduced fuel consumption subject to drivability constraints. During model validation the greatest fuel saving achieved experimentally for a warm engine was 3.6% over the New European Driving Cycle, within the constraints imposed using subjective driver appraisal of vehicle drivability. The same shift strategy for a cold start driving cycle showed a fuel saving of 4.3% over the baseline, with corresponding savings in CO 2 of 4.5% or 6.4 g CO 2 /km. For both hot and cold tests the savings were made entirely in the urban phase of the New European Driving Cycle; there were no significant differences in fuel consumption in the extra-urban phase. These results suggest that the introduction of gear shift indicators could have a substantial impact, contributing significantly towards the 10 g CO 2 /km to be achieved by additional complementary measures when assessed in this way. It is not clear whether these savings would translate into real world driving conditions, but for legislative purposes an assessment procedure based on the New European Driving Cycle remains a logical choice for simplicity and continuity.

Optimisation of the vehicle transmission and the gear-shifting strategy for the minimum fuel consumption and the minimum nitrogen oxide emissions

“…The vehicle's on-board computer is used to calculate the best gear, depending on the current speed, load and throttle position. Then, the most suitable gear is displayed by the indicator [10]. For simulation purposes it is assumed that the driver would follow the gear shift indicator or an automatic shifting system is employed.…”

“…CO 2 emissions could also be reduced by 4.5% during the NEDC [9]. Norris et al [10] showed that the gear shift indicator is able to reduce the fuel consumption by 4% and 7% for a MINI Cooper and a Ford Transit van respectively. The Volkswagen Golf tested in the same paper showed little improvement [10].The fuel savings depend highly on the vehicle and the shifting strategy.…”

“…Norris et al [10] showed that the gear shift indicator is able to reduce the fuel consumption by 4% and 7% for a MINI Cooper and a Ford Transit van respectively. The Volkswagen Golf tested in the same paper showed little improvement [10].The fuel savings depend highly on the vehicle and the shifting strategy. The use of shift indicators does not require any significant modifications to the vehicle or engine.…”

Development and Field Trial of a Driver Assistance System to Encourage Eco-Driving in Light Commercial Vehicle Fleets

“…Since minimizing engine speed is critical to the goal of reducing fuel consumption [18], it was decided to include a gear shift indicator (GSI). As many modern vehicles are equipped with GSIs as standard, the vehicle's own gear shift signal was used where available on the CAN bus.…”

Vehicle Gear Shifting Co-Simulation to Optimize Performance and Fuel Consumption in the Brazilian Standard Urban Driving Cycle

“…As described by [6] the use of gear shifting indicators, composed of light and/or sound alarms connected to a software that manage the gear shifting process, results in 3.6% of fuel economy in a vehicle submitted to the New European Driving Cycle -NEDC. With the same purpose, [7] developed a driving assistance system to help drivers giving fuel efficiency guidelines according with the current vehicle situation.…”