### Number Watch Web Forum

This forum is about wrong numbers in science, politics and the media. It respects good science and good English.

Number Watch Web Forum
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Ok, here's one for you..

Daytime running lights for cars. Try to follow the arithmetic here.

Quote:
Transport Minister Jim Fitzpatrick admitted this week that the rules, which will come into force in 2011 and relate to new cars, would lead to annual fuel consumption rising by 5 per cent. According to AA figures, for the average family-sized car, driving the average 8,770 miles a year, this would increase fuel costs by 68 pounds a year at today's prices. That is based on a car doing 31 miles per gallon. But some models do only 13mpg, meaning the increase could be as much as 160 a year. Heavy goods vehicles would see costs shoot up by 260 a year, based on the average 8.1mpg rate.

unquote:

So how exactly do the same two 55W lamps at the front and somewhat less at the rear cost 68 pounds in a small car but 260 in a truck? How does a load of a couple of hundred watts, say 1/3 HP, take 5% of the fuel? Maybe in a 6HP car! Why is it still 5% no matter how big the engine? Isn't this alarmism of the kind that gave us 'don't leave your TV on standby'?
Don't these journalists have brains to work this out for themselves, or did their education leave them quite unable to do it?

Re: Ok, here's one for you..

I'm not sure there is much benefit in making the mathematical anomalies too evident. Rather I think we should start a campaign for the saving of billions of pounds and trillions of tons of carbon by demanding that all trains and buses run without any internal lights.

Re: Re: Ok, here's one for you..

ALL
I have an old 96 ford truck. The lights work, sometimes, therefore, I am hurting fuel and oil prices when the lights are on, and aiding the fuel and oil prices when they are off, right?
Just like the spiral bulbs I bought to replace the old Edison bulbs,that still work and are currently in the local land fill, forever. Also, the spiral cost a LOT more, have mercury imbedded and will be in the future land fill for the on coming kids.
Numbers, data and the mists of arithmetic are the source of great Press Releases.
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