LED lights any good?

Two possible caveats; they may not be legal if not fitted originally, and they may flag up a bulb failure on some systems.

Chris

Depending upon the design, they can be very directional so may not provide even illumination of the lens.

Lights designed for a tungsten bulb have a reflector that takes the near omnidirectional light output and 'points' it where needed. LEDs have built in lenses to direct the rather feeble light output forward. Replacement ones tend to have multiple LEDs pointing in all directions to try and replicate the tungsten one but in the case of a stoplamp or indicator type simply aren't as bright and are a safety hazard. To the best of my knowledge there are non that are E marked and legal as a replacement - and for good reasons.

I would be very surprised if the power saving of using LEDs for sidelights and flashers would actually be noticeable to you (ie. fuel savings). As for lasting longer - probably the case but in my experience, bulbs don't tend to fail that often. At least on my cars - other people's seem to be failing all the time though. ;)

David Hearn (David Hearn ) gurgled happily, sounding much like they were saying:

No, but it would be if you were in the habit of leaving the car parked up with side/tail lights on. You'd be going from (at least) 20w draw to somewhere around 2-3w total.

I find that LED indicators and brake lights switch much more "crisply", so tend to be more visible.

They're certainly on my "To Do" list.

True - I hadn't thought of that.

If by "crisply" you mean "instant on" then yes, they do seem to be like that. Unfortunately, around here, some traffic lights have been fitted with LEDs, and certainly for me (when were first fitted), they seemed to make me feel like I need to stop quicker (or more specifically, that I had less time on amber) - which in one particular site (few feet after the brow of a hill on a dual carriageway) has caused me a few wheel-locking moments when it's damp. Haven't done it in a while though

- I've adapted now.

In a discussion on here a while back it was pointed out that this is to an extent determined by the charging voltage. Which I believe is why I have to replace our Previa brake lamps every three months or so, yet I've only replaced one bulb on my classic Elf in five years (both cars are in daily use, and the Elf does more miles!)

For this reason I would dearly love to be able to use LEDs on the Previa, but having investigated it, cannot for the reasons Dave P has pointed out.

I'd be surprised if the Previa delivered excessive voltage - most cars these days are designed for semi sealed batteries which don't like being overcharged which means limiting the peak voltage. It's more likely they overheat due to the housing design. Especially if you tend to keep the footbrake pressed when at a stop.

We had this discussion a while back.

Many cars nowadays use silver-calcium batteries. For example, all Fords have used them since around mid-1999. These have a number of advantages in terms of longer life and lower maintenance. For example, water loss is around 10% of a conventional battery. Also, gassing is minimised so in actual fact they will be more tolerant of an over-charge situation.

They do require a higher charging voltage (typically 14.8v), in order to reach a state of full charge. This is why it is safe to use a silver technology battery in a car that has the charge rate set for a conventional one, but an old technology battery should never be used in a car that has the higher charging rate required by the silver technology ones.

Chris

As it's an automatic, that is largely the case.

The Previa is an older model, 1996 (we had the same issues with our 91 model too). It's not that.

They turn on more crisply, but I can't see LED indicators in bright sunshine so if I was in charge I would make them illegal!

I find the LED brake lamps VW use to be pretty invisible unless you're staring at the arse of the car in front of you.

Yes - I've noticed that with the indicators. A few degrees off axis on a sunny day and you can't see them at all. And all the more important with indicators than brake lights.

If the standard voltage is now 14.8 rather than 13.8 I'd expect things like stop bulbs to blow in short order unless specially designed for this higher voltage. It's a a very non linear law the relationship between tungsten bulb life and overvoltage. Of course perhaps they mainly use LEDs and HID types for the brighter ones?

Most "old" alternators are regulated around 14 to 14.2 volts, so not quite that big a difference. Still significant though.

Yes, it's certainly noticeable to me that more cars than ever have at least one bulb not working.

Nope!

Chris