Yes you do if you downloaded my spreadsheet posted in another place. However for those who didn't the flywheel bhp used by an average car (my Focus) at various speeds is as follows.
30 - 5.2 40 - 8.6 50 - 13.4 60 - 24.0 70 - 28.6 80 - 39.6 90 - 53.5 100 - 70.5Some quick calcs show that keeping the headlights on would cost about £6 to £7 every 10,000 miles for an average car. About 0.005 of the total fuel consumption.
Aie I could very probably keep the light switch at the dipped position as almost all of the time I drive from October through to April, I need the headlights on. The only time I don't need the lights on is on those rare Saturday or Sunday lunchtimes when we use the car.
You mean the rain sensor comes on with the ignition? Isn't that a bit risky if using a car wash?
BTW - it must be very much better than the BMW rain sensor if you find it works perfectly all the time...
Here is the link if anyone wants it.
It's an old Dos based Quattro Pro format file but Excel or Lotus should be able to read it. If someone wants to convert it to Excel format I'll host that too.
You can switch it off. But I never to, 'cos I use the local Polish carwash on an old forecourt, so the engine isn't running whilst they're washing.
With the BMW it has to be reset each time you start up - even if you've left the lever in the sensor position.
I seem to remember that GM brands are like this too.
Nah, I've just driven from Edinburgh to Manchester. Started off in bright sunshine, finished in the dark. Everyone switched lights on in a timely manner, just one chap didn't - he turned them on when someone flashed him, so he had obviously forgot.
(In a petrol Focus hire car BTW with 5k on the clock - a horrid thing with a gutless engine, my old turbo 306D was far far more fun to drive!)
Julian.
It's the ones who don't switch them on in the pouring rain that baffle me. Although possibly they never use their wing mirrors either.
Yes, but the diodes are not the main reason for the poor efficiency - it's because the car alternator is a 'jack of all trades' electrical machine which must produce an output over a huge RPM range - big design compromises are therefore required. Next time you take a journey in the car with the lights on feel the stator laminates with your fingers after you stop - you'll soon discover what's producing the heat.
I'll point you to a site that details the car alternator shortcomings if you like - for this reason they are a poor choice for wind generators and CHP plants etc.
Julian.
Yes, and the closest I came to crashing was when I tried to get the effing trip computer from kms to miles, nearly rammed someone up the arse. Stupid Frog language too, so I managed to switch off the ESP by mistake and then took 10 minute. getting it back on again.
Trying to work all the effing pointless stupid gimmicks on the thing while moving is far more dangerous than leaving your headlights off if the sun should so much as dare to hide behind a cloud for a few seconds!
Julian.
Err yes.
That's a very good point.
Recently I acquired an Astra van cdti. The yellow emissions light came on so I purchased a good code reader. One thing it can do is read ''real time'' data. At idle the engine load is about 20%, switch lights on and it rises to about 30%, (I'll try again in the morning just to make sure I'm not spouting rubbish) by my calculations that represents about a 33% increase in fuel consumption at idle to power the lights?
Julian.
50% increase... either way it's much higher than my Ka, which went from ~26% to ~29% with main beam, closer to a 3% increase.
Shows how horribly inefficient petrol engines are at idle - pumping losses caused by the throttle plate.
I'm off to try the Astra now, I might have been talking bollocks last night, watch this space....
Julian.
Here we go, 1.7cdti Astra.
Calc load at idle revs:
nowt on 25% headlights 31%
It's a pity there's no aircon compressor to try out too....
Julian.
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Angus Manwaring" saying something like:
As near to f*ck all as makes no difference.
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "DervMan" saying something like:
I'd cheerfully pay the extra quid a year it costs to have my lights on whenever the day's a bit dim, rather than have some divot run into me.
Yup, but they won't listen. Normally the same people who wreck their air conditioning systems by never running them, and then complain bitterly when their car has devalued because the AC doesn't work.
I'm sure they think they'll get a bill through the letter box one day. "4 minutes use of heated rear window - £56,000,00"
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