Background

Divergence in fuel consumption (FC) between the type-approval tests and real-world driving trips, known also as the FC gap, is a well-known issue and Europe is preparing the field for tackling it. The present study focuses on the monitoring of the FC of a single vehicle throughout 1 year with 20 different drivers and almost 14,000 km driven with the aim to analyze and quantify the true intrinsic variability in the FC gap coming from environmental and traffic conditions and driving factors. In addition, the regression model has been developed to evaluate the importance of these different factors on the FC gap’s variability.

Results

The 1-year FC gap measured in this study was 29% while driver’s averages were in the range from 16 to 106%. The regression model developed had \(R^{2}\) equal to 90.4 meaning that more than 90% of the FC gap’s variance can be explained with this model and factors measured in this study. The results of the model showed that among all factors analyzed the highest contribution in the FC gap’s variance is coming from the average vehicle speed (16.6%), followed by the road grade (13.4%), and trip distance (10.1%). Indeed, the highest FC gaps are measured when the average vehicle speeds were below 20 km/h, the average distance-weighted road grades above 1%, and the trip distances below 5 km. In addition, the impact of driver factors is not negligible (25%) and the highest FC gap is measured for the trips where average positive acceleration was higher than 0.7 m/s² (indicating aggressive driving) and the electric power demand higher than 800 W.

Conclusions

The future lifetime on-board fuel consumption reporting is a crucial instrument that will allow the monitoring of the evolution of the FC gap and ensuring that it does not increase over time. The analysis presented in this study is a basis for setting up a more detailed and refined prediction model, which could assist the European Commission in closely monitoring the gap and the underlying factors generating it.

中文翻译：

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了解燃油消耗差距的根源和可变性：从实验室测试和实际驾驶活动中学到的经验教训

背景

型式认可测试与实际驾驶旅行之间的油耗（FC）差异（也称为FC差距）是一个众所周知的问题，欧洲正在为解决这一问题做好准备。本研究着重于在20年内驾驶员和将近14,000 km的驾驶情况下，对单个车辆的FC进行的整个一年的监测，旨在分析和量化来自环境，交通状况和驾驶因素的FC间隙的真正内在变化。 。此外，已经开发了回归模型来评估这些不同因素对FC差距变异性的重要性。

结果

在这项研究中测得的1年FC差距为29％，而驾驶员的平均值在16％至106％之间。开发的回归模型具有\（R ^ {2} \）等于90.4，意味着该模型和本研究中测量的因素可以解释超过90％的FC缺口方差。该模型的结果表明，在所有分析的因素中，FC差距变化的最大贡献来自平均车速（16.6％），其次是道路坡度（13.4％）和出行距离（10.1％）。确实，当平均车速低于20 km / h，平均距离加权道路坡度高于1％，出行距离低于5 km时，才可以测出最高的FC间隙。此外，驾驶员因素的影响不可忽略（25％），并且对于平均正加速度高于0.7 m / s ²（表明激进驾驶）且电力需求高于800的行程，测量出的最大FC间隙W.

结论

未来生命周期机载燃油消耗报告是一项至关重要的工具，它将能够监控FC差距的变化并确保其不会随着时间的推移而增加。本研究报告中的分析为建立更详细，更精确的预测模型奠定了基础，该模型可以帮助欧盟委员会密切监控缺口和产生缺口的潜在因素。