We already knew that turn signal DRL's were a bad idea...
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From: Daniel J. Stern on 5 Nov 2007 19:37 On Nov 4, 6:26 pm, Nate Nagel <njna...(a)roosters.net> wrote: > I coulda swore that there was a FMVSS that required non-replaceable > lenses No. The requirements for reflector durability and seal integrity are more stringent for headlamps with replaceable lenses, though, and for that reason it is more costly in the North American market to equip a car with replaceable-lens headlamps. Reflector durability and seal integrity are very important to the long-term safety performance of a headlamp; I would like to see the more stringent requirements effected across the board (w/ or w/o replaceable lenses), which might tend to cancel or at least reduce the market disincentive towards replaceable lenses. > I've never seen a glass lens on any US-spec vehicle. You haven't been looking! Off the top of my head, here are some cars with glass-lens replaceable-bulb headlamps in the North American market: -Volvo 850 and at least the first several years of S/V70 -Saab 900 '86-'98, 9000 '86-'98, 9-3 '99-'02, 9-5 '99-'01 -Chevrolet Cadavalier, '8?-'9? -Chevrolet Caprice, '87-'90 -Audi 5000, '85+ -Mercedes-Benz, all models '85 until at least 1999, some models thereafter -BMW, all models '89-91, some models thereafter There are many others. DS
From: N8N on 6 Nov 2007 09:44 On Nov 5, 7:37 pm, "Daniel J. Stern" <dast...(a)engin.umich.edu> wrote: > On Nov 4, 6:26 pm, Nate Nagel <njna...(a)roosters.net> wrote: > > > I coulda swore that there was a FMVSS that required non-replaceable > > lenses > > No. The requirements for reflector durability and seal integrity are > more stringent for headlamps with replaceable lenses, though, and for > that reason it is more costly in the North American market to equip a > car with replaceable-lens headlamps. More stringent than ECE? I have in my posession a factory set of ECE headlamps for a Corrado G60 so they are 17 years old at the newest and they are certainly in MUCH better shape than the US-spec ones removed from the car. They do have replaceable glass lenses, held to the plastic housing by metal clips and what appears to be a silicone rubber seal (although I'm guessing on the seal material.) > Reflector durability and seal > integrity are very important to the long-term safety performance of a > headlamp; I would like to see the more stringent requirements effected > across the board (w/ or w/o replaceable lenses), which might tend to > cancel or at least reduce the market disincentive towards replaceable > lenses. No argument here, although I would think that replaceable lenses would still be a bonus in terms of long-term maintainability; if a glass lens becomes overly pitted or a polycarbonate lens becomes hazed, it would be nice to have the option to simply replace the lens without having to purchase either a complete new headlamp assembly from the dealer ($$$$) or a "good used" junkyard unit that may not be significantly better than the one removed. The biggest problem that I see is hazing of the polycarbonate lenses, this seems to be a nearly universal problem with any car more than a few years old. Some worse than others, for sure, but eventually they all seem to haze over. > > > I've never seen a glass lens on any US-spec vehicle. > > You haven't been looking! Off the top of my head, here are some cars > with glass-lens replaceable-bulb headlamps in the North American > market: > > -Volvo 850 and at least the first several years of S/V70 > -Saab 900 '86-'98, 9000 '86-'98, 9-3 '99-'02, 9-5 '99-'01 > -Chevrolet Cadavalier, '8?-'9? > -Chevrolet Caprice, '87-'90 > -Audi 5000, '85+ > -Mercedes-Benz, all models '85 until at least 1999, some models > thereafter > -BMW, all models '89-91, some models thereafter > > There are many others. > > DS Of the above, BMW is the only one that I have had any contact with whatsoever, and at least the 3-series of a couple years ago used plastic. Certainly the vast majority of vehicles on the road today have either sealed beams or polycarbonate-lensed aero-style headlights. nate
From: N8N on 6 Nov 2007 09:48 On Nov 4, 5:37 pm, "Daniel J. Stern" <dast...(a)engin.umich.edu> wrote: > On Nov 2, 2:37 pm, N8N <njna...(a)hotmail.com> wrote: > > > signal ambiguity... a good enough argument in and of itself > > for disabling them. > > Yeah...I'm not so sure that's really been a problem. A little thought > with respect to implementation cuts it significantly, and proper > selection of light sources for adequately long life cuts it still > further. Other countries (e.g. Australia) have been eyeing the turn > signal DRL for use exclusively on motorcycles, to differentiate them > from automobiles. If that pans out as a beneficial measure, it'll be a > pity we won't be able to adopt it because of the existing installed > base of turn signal DRLs on cars and trucks. > > But overall, if one cannot have a functionally-dedicated DRL, the turn > signal DRL is a great deal less problematic and potentially more > beneficial than any headlamp-based implementation. > > There are some really nice LED DRLs presently and "coming soon", both > at the OE and aftermarket level. And BMW have just begun running extra- > bright inner "angel eyes" as effective nonglare DRLs in the daytime > and front position "parking" lamps at night - it takes more power than > turn signal or LED DRLs, but less power than headlamp DRLs. > > And there's still a great deal of debate regarding the efficacy of > DRLs as a safety device. The matter is generally being decided in > various jurisdiction on political as much as safety grounds. > > DS Can't argue with that last sentence :) Personally I don't care that much for DRLs as most implementations seem to range from "outright offensive" (early Saturn) to "merely less than optimal" (turn signal) and there are very few implementations that I really feel good about. I'm curious what your objection is to reduced-power low beam DRLs, as those seem to be pretty inoffensive, is it that they don't provide the same conspicuity benefit as a dedicated DRL with an optimized beam pattern for the application? Granted they do result in reduced headlamp life, but I put over 40K miles on my '02 GTI without having to replace a bulb, likewise with my '05 Impala, both cars spent a lot of time in city traffic so operating hours are probably higher than average for the mileage. nate
From: Daniel J. Stern on 6 Nov 2007 15:38 On Nov 6, 9:44 am, N8N <njna...(a)hotmail.com> wrote: > > The requirements for reflector durability and seal integrity are > > more stringent for headlamps with replaceable lenses, though, and for > > that reason it is more costly in the North American market to equip a > > car with replaceable-lens headlamps. > > More stringent than ECE? Yes. > I have in my posession a factory set of ECE > headlamps for a Corrado G60 so they are 17 years old at the newest and > they are certainly in MUCH better shape than the US-spec ones Nice anecdote ;-) > > Reflector durability and seal > > integrity are very important to the long-term safety performance of a > > headlamp; I would like to see the more stringent requirements effected > > across the board (w/ or w/o replaceable lenses), which might tend to > > cancel or at least reduce the market disincentive towards replaceable > > lenses. > > No argument here, although I would think that replaceable lenses would > still be a bonus in terms of long-term maintainability Agreed! > > > I've never seen a glass lens on any US-spec vehicle. > > > You haven't been looking! Off the top of my head, here are some cars > > with glass-lens replaceable-bulb headlamps in the North American > > market: > > > -Volvo 850 and at least the first several years of S/V70 > > -Saab 900 '86-'98, 9000 '86-'98, 9-3 '99-'02, 9-5 '99-'01 > > -Chevrolet Cadavalier, '8?-'9? > > -Chevrolet Caprice, '87-'90 > > -Audi 5000, '85+ > > -Mercedes-Benz, all models '85 until at least 1999, some models > > thereafter > > -BMW, all models '89-91, some models thereafter > > > There are many others. > Of the above, BMW is the only one that I have had any contact with > whatsoever, and at least the 3-series of a couple years ago used > plastic. Yes...the numbers after the makes in my list above are model years. > Certainly the vast majority of vehicles on the road today > have either sealed beams or polycarbonate-lensed aero-style > headlights. Sealed beams are almost absent from the market any more. Most headlamps in North America do these days have polycarbonate lenses...but not because there's any law saying they have to. DS
From: Daniel J. Stern on 6 Nov 2007 15:45
On Nov 4, 6:26 pm, Nate Nagel <njna...(a)roosters.net> wrote: > >>According to Sylvania's web site, yes - 3157LL > > > Probably because Sylvania don't supply the correct bulb, which is > > 4114K (much longer life and slightly cooler running than 3157LL). > > Apparently GM did not either, the 3157LL was in there previously. > Unless it'd already been replaced. Well, GM have certainly done stupid things before. Let's see if this is one of them. Here are some major (bright) filament life ratings for various S8 wedge-base bulbs physically, electrically, and photometrically compatible with one another: 3157LL (3157K): 2k hr @ 12.8v, 1k hr @ 13.5v, 624 hr @ 14.0v 4157K (4157LL): 4k hr @ 12.8v, 2k hr @ 13.5v, 1.2k hr @ 14.0v 4114K (4114LL): 12.8k hr @ 12.8v, 6.4k hr @ 13.5v, 4k hr @ 14.0v Which looks like the smart choice for DRL service? Which looks like the dumb choice? DS |