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Environmental impact
DRL power consumption varies widely depending on the implementation. Current production DRL systems consume from 8 watts (dedicated LED system) to over 200 watts (headlamps and all parking, tail, and marker lights on). International regulators, primarily in Europe, are struggling to balance the potential safety benefit offered by DRL with the increased fuel consumption due to their use. Because the power to run the DRLs must be produced by the engine, which in turn requires burning additional fuel, high-power DRL systems increase CO2 emissions sufficiently to affect a country's compliance with the Kyoto protocol on greenhouse gas emissions.[4] For that reason, low-power solutions are being encouraged [5] for use when and if DRL become mandatory in ECE Regulations. LEDs and low-wattage, high-efficacy, long-life light bulbs produce appropriate amounts of light for an effective DRL without significantly increasing fuel consumption or emissions. Fuel consumption reductions of up to 0.5 mpg may be found when comparing a 55-watt DRL system to a 200-watt DRL system. [6] In 2006, the UK's Department of Transport also found significant reductions in emissions and fuel consumption when comparing a 42-watt DRL system to a 160-watt full headlight DRL systems. [7] DRL fuel consumption can be reduced to insignificant levels by the use of 8- to 20-watt DRL systems based on LEDs or high-efficacy filament bulbs.
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