Fog lights ?

[smartHHO]

Them Driving lights are not real FOG lights. Real ones have a yellow case. Those be Driving lights. And for the record, they lower your MPG by about 1 - 3 per gallon depending on the type of car. This is in part due to they put a nice drain on your battery which makes your alternator kick on and thus making your engine work harder.

[NCC1701]

Originally Posted by smartHHO

they lower your MPG by about 1 - 3 per gallon depending on the type of car. This is in part due to they put a nice drain on your battery which makes your alternator kick on and thus making your engine work harder.

I know you don't get energy from nowhere. But, I am surprised the impact is that substantial. Wow!

[smartHHO]

Originally Posted by NCC1701

I know you don't get energy from nowhere. But, I am surprised the impact is that substantial. Wow!

Yep, it is. Been doing experimentation with the Water into H H and O. Thus my name on the forums. If I get a good system down and working real good, I am going to hook one up on the smart car to push it past the 65 or 70 mpg. Thus a plate that says 80mpg like the one girl has, won't be a fib, but actually telling what it is. Then, if it works great, I might actually sell you all the plans so you can thus have a HYBRID Smart that gets better MPG then that stupid looking Prius.

[alecadi]

A common mistake: the alternator doesn't "kick on.." the alternator doen't have a clutch and is ALWAYS connected to the engine via belt and wheels, it's always revolving acording to rpm but not according to electricity charge or consumption. SO NO IMPACT AT ALL ON MPG

[msjohnson1974]

Originally Posted by alecadi

A common mistake: the alternator doesn't "kick on.." the alternator doen't have a clutch and is ALWAYS connected to the engine via belt and wheels, it's always revolving acording to rpm but not according to electricity charge or consumption. SO NO IMPACT AT ALL ON MPG

Pretty much, I'd like to see proof that using fog lights drops MPG. Sounds like an urban legend.

The fog/driving lights are great for rainy nights when you can't see the lines on the road. Other than that I don't use them.

[NCC1701]

I use them quite a lot ... for improved vision and visibility.

[retiltxet]

Originally Posted by smartHHO

Them Driving lights are not real FOG lights. Real ones have a yellow case. Those be Driving lights. And for the record, they lower your MPG by about 1 - 3 per gallon depending on the type of car. This is in part due to they put a nice drain on your battery which makes your alternator kick on and thus making your engine work harder.

I call major BS on that one. The alternator is always connected and while the regulator would place more load on it, no significant decrease. There was lots of research done on this..

Read #5. While it applies to DRL's which are headlights, fog lights dont use much more.

Q&As: Daytime running lights

[NCC1701]

OK, I'll admit I've considered this before. Although I have a pretty good science background, not so much on the technicalities of automotive engineering. I'm not so swift on alternators / generators either. Although the alternator is always turning, is it always putting out the same current? And, if the answer is no, does it require more energy to turn it when it is cranking? If its normal state is putting out more current than is required by the system, where does that current go?

I already admitted ignorance, so no need to rub that in. Life is learning.

[msjohnson1974]

How I understand them to work is that the raw output is determined by how fast the alternator spins and how the alternator is constructed (how many coils of wires and the size of the magnet used). More power is generated when the engine is turning faster, but there is a voltage regulator that keeps the voltage at a constant level. Alternators have power ratings which represent how many amps they produce and at what output voltage which is kept at a constant output based on the voltage regulator.

We probably need an engineer to explain fully... and in depth.

[retiltxet]

Well while the alternator is always spinning, the "load" on the alternator does not stay constant. Think of it as a magnetic brake except in reverse. It becomes "harder" to spin the alternator.

The people who want you to turn off your fog lights, are the same people who turn off their cars and coast to a stop...