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Are daytime running lights a waste of energy?

I understand that there are approximately 35 million vehicles registered in the UK. If we therefore assume that 1 million of them have unnecessarily deployed side and dipped headlights at any one time, particularly during good visibility daylight hours, then, according to my calculations, this would be equivalent to an electrical energy input of 375 megawatts. Am I correct? If so, then isn't it about time someone told my fellow drivers that there is no such thing as 'free electricity' in vehicles? Please feel free to correct my assumptions.

Asked on 9 February 2013 by MFR, Hundon, Suffolk

Answered by Honest John
If you check your fuel economy you will find that there is such a little difference between driving at night with your lights on and driving in the daytime with them off that it is undetectable. However, DRLs are preventing significant numbers of crashes, injuries, deaths and the timewasting from blocked roads, forensics and clean-up operations.
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