LED lights

LED should last a lot longer.
Yes, LED's save electricity, but i'm not sure how measuralbe it is in MPG's
I do like my LED's on my 2015 prius, but i'm not sure i'd change to them on my 2011 prius

 

While small, that does add up -- under 1 mpg at highway speed, but several mpg in stop-and-go city traffic.

Does the law in your country mandate actual low beams, or are DRLs (Daytime Running Lights) acceptable? The DRLs on U.S.-market 2012+ models are 7.2W each, or 14.4W for the pair. They won't retrofit to your 2010, but similar aftermarket solutions do exist.

 

I installed LEDs on my 2010 recently - you can find more info and photos here: LED headlights in original projectors (2010 gen 3) | PriusChat

The bulbs have a fan at the back, but it's not getting hot at all. I was curious too, so I touched it after the headlights were on for a long time, and every time it's like room temperature metal (same after driving and after being parked/stationery; also, weather since the installation is between 5-15 degrees C).

 

On the Prius and some other very recent car models, the DRLs are LED strips.

But DRLs have been around since before white LEDs were developed. On most North American cars with DRLs, the function was originally (and usually still is) produced by normal high beams operated at reduced voltage (and power). Some DRLs may be true low beams.

Do your country's laws very specifically and narrowly require low beams? Or is the language broad enough to merely require a certain level of daytime visibility, giving designers flexibility in how this is achieved and allowing for new innovations to be introduced? The later ought to allow you to use any of the DRL varieties commonly used in other countries.

 

Not sure what that is to be honest, but I did notice that not all LEDs have it. I'm suspicious it's only there for "decoration" Here's the one I got: http://amzn.to/2jAmJUT

 

A gallon of gasoline can provide 36000 watts. So a consumption rate of 50 mpg equals 732 watts per mile.

I believe a bulb's rating is the power consumed per hour. So, for example: a change from 100W to 50W would equate to a reduction of 50W in one hour.

If you're averaging 50 mpg while traveling 50 mph, then a bulb reduction of 50W consumed in one hour would allow an increased range of 50W/732W per mile = .0683 miles = 360.6 feet (during a 50 mile trip).

 

Impressive! So -50W improves MPG by 0.1366%

 

Anything above zero is good I personally went for the LEDs chasing a combination of better light & cooler light temperature. The yellow of the halogens is not my favourite, and especially after installing the T10 LEDs parking lights, the H11s looked so yellow in context!

 

Just because a Switch Mode Power Supply is driving it, doesn't mean the LED itself is flickering to any significant level. In that particular circuit, D1 and Cout filter out nearly all the flicker voltage, and keep the LED running continuously.

Unlike the dim beasts of decades ago, modern high efficiency LEDs are more efficient running continuously than pulsed.

Make that watt-hours.

As a fuel-air munition, all burning in a fraction of a second, a gallon of gasoline can provide over a billion watts.

 

I originally responded to this thread with a question about how flexible OP's country's law may be on this issue. Is the language restrictive, declaring exactly how the result must be achieved (i.e. daytime lowbeams specifically required)? Or is it flexible enough to allow non-traditional solutions such as the LED-DRLs on the 2012+ Prius and many other recent North American market cars?

No answer has been forthcoming.

The square wave is only on the inductor (L1) side of the diode, not the LED (and Cout) side. The LED is meant to be driven with a constant current, not a flickered or pulsing current. A small triangular ripple current is present in this particular case, but it is very small compared to the DC current.

I'll call 'bull' on that.

A generation ago, defects in the active junction produced LED output-vs-input efficiency graphs that were zero or very low for the first few milliamps, then improving at higher currents. With these devices, high current pulses produced higher illumination efficiency than steady DC current. But even at their very best, overall light conversion efficiency was several orders of magnitude lower than today.

Modern high efficiency LEDs were developed by, among other things, identifying and getting rid of those previous-era junction defects. Modern LED output-vs-input efficiency graphs show very high efficiency even at the very lowest currents, then dropping off slightly (but not painfully) at higher currents. Steady DC currents now produce (slightly) better illumination efficiency than do the old-fashioned high current pulses.

Some LEDs are still driven with pulsed currents, but that is for control and other reasons. That includes efficiency of the driver or controller device, but not efficiency of the LED itself.

 

Not really - very few resources available. When I realised they were relatively cheap (in comparison to HIDs) so I though to give them a try.