Plastic Not-So-Fantastic

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I miss glass headlights.

They didn’t yellow and haze over like a 90- year-old man’s rheumy eyes – like modern plastic headlight “assemblies” always do after just three or four years. Then your car looks old, too. While it’s true the modern plastic “assemblies” are brighter when new, when old, their light output drops as the outer lenses fog up. Sometimes, you can cure this by polishing the outer plastic but if you aren’t vigilant and don’t catch it in time, the yellowing is often too far gone to do anything about short of replacing the “assembly” – each of which typically costs $150 or more. And then you’ve just re-set the clock. In another three or four years, you’ll have to do it again – or live with the ugly, old-man-looking headlights.

Glass headlights never yellowed – and when you needed to replace one, the cost was (and still is) about $25 or so. Is the trade-off worth it? Maybe – maybe not. One thing’s for sure. Thirty or forty years down the road, replacement “assemblies” will probably be unavailable for most current-era cars.

In contrast, you can still find new headlights for virtually any car made from the Model T through the early ’80s.

Plastic headlight assemblies: They part of the built-in life-clock of modern cars.

Oh, and you can thank the government. Plastic headlight assemblies are lighter than glass headlights. Several pounds can be saved per car – and several pounds less  per car means slightly better fuel economy per car. It’s one of the ways the car companies try to counterbalance the growing beef of cars resulting from (here it comes) government mandates. One mandate (bumper impact standards, for example) results in higher curb weight. Another mandate says the car must deliver “x” MPGs. The first one results in a heavier car – the second in pressure to lighten the car up somehow.

Plastic headlights are one way how.

LED lights. Many new cars have these, two. They’re very pretty. And they’re also pretty expensive. Each LED light can cost $20. Some models have a dozen of them built into the brake lights. And at least in my state, all of them have to be working in order to pass the mandatory annual safety inspection.

Don’t forget the CHMSL – the third brake light. There’s often LED lights in there, too.

Plastic intake manifolds. Saves a lot of weight (maybe five pounds or so vs. 30 or 40 for an old-style cast iron manifold) and easy to manufacture to precise tolerances and in shapes that would be hard if not impossible (economically) to do with iron or even aluminum. That’s the good part. The bad part is that plastic is less long-term durable than iron or aluminum. Iron is almost impossible to hurt. Aluminum is tough, too. Manifolds made of either will usually last for a human lifetime if not longer. But plastic has a shorter shelf life. It is also easier to crack. And plastic decomposes – literally begins to crumble and fall apart – after about 20 years.

These things aren’t an issue – usually – for the first ten or fifteen years or so. But after that, to quote OJ – look out.

This is another reason why today’s cars will probably never be classic cars thirty or forty years from now. They’ll be recycled long before then – because it’ll be difficult if not impossible (economically and otherwise) to keep them operable. At least, not without gutting and replacing the original components – and even entire drivetrains – with whatever’s available thirty or forty years hence.

Where am I going with this?

I’d like to see less-disposable cars again. Cars that can be kept almost indefinitely – as opposed to cars that are superb for about fifteen years or so – but then rapidly deteriorate beyond the point of economic salvation, let alone resurrection. This is the opposite of the way cars used to be – before the mid-80s or thereabouts. They were often far from superb when new – and almost always showed signs of decay within five years or so. Paint would fade; engines would get loose. But, they were fixable.  Almost indefinitely so. And relatively cheaply so, too. The engine in my ’76 Trans-Am, for example, is a 400 pound lump of cast iron that can be fairly easily and fairly cheaply rebuilt almost without end. A $2,500 engine rebuild will last about ten years – and ten years later, can be done again for the same amount of money. This can be repeated almost indefinitely.

There are 100 year old Model Ts still in roadworthy condition; people still drive 40-50 year old VW Beetles every day. Sure, they need This or That more often than a brand-new car. But This is usually cheap and That is usually easy – not so much with anything new.

And when the new car is 40 or 50 years old, good luck finding a replacement headlight “assembly” – or a new replacement plastic intake.

Throw it in the Woods?


  1. On a related note, it is becoming almost impossible to get my eyeglass prescription in glass anymore. I usually wind up going from place to place and paying quite a premium, while listening to all the propaganda about being lighter, available with ‘scratch resistant’ (joke) coating etc.
    But the truth is, when I go to refresh my eyeglass lenses after 2-3 years they are far clearer than plastic lenses after 3 weeks.

  2. This thread raises a good question: if the feds are going to get involved with mandating everything, then why aren’t such things as obsolescence, deterioration, and maintainability addressed?

    The easy solution to the issue Eric discusses would be to require that headlamp assemblies use glass instead of clear plastic as had been the case with many of the first aero headlamps.

    Sun exposure isn’t the only problem, incidentally. Constant airflow and exposure to light impacts from bugs and weather yellow these lamps too. Taillamps have long been plastic too, but deterioration is relatively rare and usually entails colors fading if it does happen on certain vehicles. That is because the lamps do not face direct airflow at speed, whereas headlamps do, all the time.

    LEDs aren’t necessarily the answer to anything, by the way. I’ve seen new cars with failed LEDs within a (very expensive) taillamp cluster. Some of the aftermarket LED taillamp units used in such applications as trailers (e.g., for tractor-trailers) often have multiple individual LEDs burnt out, diminishing output badly. There has been a lot of talk in other forums about the poor quality and durability of LEDs from such places as China and (gulp) Korea that are making their way onto new cars. An SAE technical paper several years ago raised the issue about when an LED lamp ceases to meet requirements as elements are lost, so this is nothing new.

    Best guess on the future: really popular cars still in wide use such as the ’96-’99 Taurus will long have replacement headlamp units available cheaply (as I was able to do for my recently retired ’98 for under $100 a pair). Less popular vehicles, well… Out back, buddy.

  3. Back in the old days, I never appreciated sealed beams (Euro lights were brighter anyhow). But you get a new lens and reflector each time you change the bulb… not a bad idea.

  4. The other big issue with plastic anything is lack of flexibility at low temperatures.

    If anybody lives in a cold climate and doesn’t have the luxury of a heated garage, plastic is very brittle in the winter.

    Do not try to remove door panels, trim, or anything else plastic that is supposed to “flex” when it is cold. It will not flex – it will just snap. UV exposure and age make it even more brittle.

  5. Is it still called technologically advanced when it doesn’t last as long, is more expensive, is a hell of a lot harder to remove and replace, and is built with planned obsolescence in mind?

    Am I missing something?

    I don’t get it!

  6. I have a 2004 Ford Explorer with 324,000 miles on it. The headlights are still clear. It runs great, doesn’t use oil between changes, doesn’t drip. Another thing it does just fine is get on the freeway with the car trailer in tow–something my 2000 GMC Sierra had trouble with.

  7. Obama’s lawyer Alexandra M Hill admits in NJ that Obama’s birth certificate submitted online in April 2011 is a forgery. Claims it is so obviously a forgery, that it presents no problem for his continuing to hold office and run for re-election.

    Republicans have presented a bill turning jurisdiction of federal land within 100 miles of either Canada or Mexico over to the DHS.
    Get ready for a fondling next time you want to visit a national park and eventually all public spaces.

  8. Had to change a headlight assembly in my wife’s Civic and now it looks really stupid with one clear light and one sickly jaundiced looking thing. Didn’t even think of it at the time; of course even if I had it doesn’t look stupid enough for me to shell out the coin it’s going to take to replace the other one.

    Then on the flip side, when I bought my ’67 Skylark in ’99 it still had T-3s in the hi-beam sockets. Older is definitely better.

      • Got it for 50 bucks through Certifit; I was surprised when I went to look at the receipt. For some reason I remembered it costing a lot more than that. Maybe I will go back and get that other one…

    • @That One Guy: Back when I owned my ’87 T-Bird Turbo Coupe, the headlights on it had yellowed pretty badly. I bought some plastic polish and restored them to practically new clarity for under $20 bucks. I think what I used was Mother’s but I know 3M makes a headlight restoration kit for around that price as well. The yellowing / haze appears to be a fairly shallow surface deterioration that isn’t too difficult to remove. You might want to consider that on the Civic.

  9. Early areodynamic headlamps were glass. These are found almost entirely in mid-late 80s models. Right after the sealed beam requirement was finally dropped.

    What is good about sealed beams is that they could be replaced easily with lamps that had proper beam characteristics and were bulb replaceable. (headlamps made to european standards)

    I haven’t much trouble with plastic headlamps. Just on my ’97 when I got sick of polishing them. Got some chinese knock offs for another variant of the same model. It was actually an improvement performance wise.

    What matters with plastic headlamps is the time the car is exposed to UV and if the hardcoat breaks down. Not sure if someone makes a do-it-yourself spray on hardcoat or not. If not, there’s a business opertunity for a general aerosol company… Just don’t let Elwood take any home 😉

    • When I hit the %$#@!! deer last year, it ended up costing me more to replace the passenger’s side headlight assembly than the entire passenger side front fender, including paint!

      • LED lights you say are expensive but I would guess they would outlast the vehicle and save you gas the whole time. It takes energy and HP to run the old lamps.

        My car is now over 4 years old and the headlamps look like new. I try not to leave it parked in the sun all day. Yes everyone is not able to do that but there are cheap polishes that work very well to get rid of the haze.

        You forgot, the deer hit you. You are incapable of hitting anything. He hit the side of your car if I remember right.


        • And Clover is incapable of basic math. You won’t notice the difference of LED bulbs in fuel economy. It’s fuel economy for the sake of the EPA tests.

          The regular light bulbs last a long time and the replacement cost means keeping a car longer than I do to break even with LED taillamps. One can like the LED taillamps for other features, but cost isn’t one they win on.

          • Yes you will not notice the gas savings when driving down the road. You also will not notice the gas savings by removing your so called 50 lb spare tire either but over the life of the vehicle the gas savings is a lot more than the price of the LED lamps. The savings between lamps would be anywhere between 10 to 20 watts per bulb. That makes your alternator work less and also your engine if you have that much savings per bulb. Again I believe in investing for savings. If it costs me 20 more bucks at purchase time and saves me 100 bucks down the road then it is not even an option for me what to do.

            Investing can be a good thing. Thanks Apple for the new car today that I will buy in the future.


          • Brent, have you priced them? I know you didn’t! The price of some of those bulbs is 3 to 4 bucks! Hundreds? No not hundreds. You are good at making things up and maybe if you keep it up there is one person out there that will believe you.


            • Well, little Clover, had enough correction for one day? Brent dissected your latest idiocy rather completely, eh?

              There’s no question in my mind you post solely in order to try to get a rise out of people. The alternative explanation – that you really are that dumb – is very hard to get one’s head around.

              Then again, it’s abundantly clear such people are out there in their millions. So perhaps I ought not to be surprised.

          • Clover, in the mustang world people are about modifying the cars to their own tastes. Many really like the 2013 taillights and want to use them on their 10-12’s. They will fit well enough. So they’ve priced them out from the dealer. $900 PER SIDE. Now generally that means the dealer paid around $450, the distributor around $225 and the manufacturer around $113. Just round numbers with doubling at each step. So, $225 for the pair on the new car.

            When they were still bulbs, Cobra export taillamps retailed for ~$600 a pair. So, the dealer paid $300, dist, $150, manufacturer $75. And those were low volume lamps, not full production, so the cost to the manufacturer was probably higher than the regular production taillamps.

            Mind you this is for much simpler taillamps. Not head lamps.

            The problem is you think that an LED bulb can just be stuffed in current lamps. It can’t. The optics are completely different. Now of course there ways the aftermarket comes up with to do it, and most of it doesn’t work like it should. Like the HID retrofits.

            Simply put, you’re once again arrogantly assuming you know all there is to know. You don’t.

            BTW, headlamp bulbs aren’t $4. Last set cost me like $15 a pair.

          • Brent there are direct replacement tail lights, dome lights, plate lights and running lights. Most of them are 3 to 4 bucks. If you want to pay for some manufactured light assembly bought from the dealer then I guess you will pay hundreds. It probably costs less than 15 bucks at the most to manufacture that assembly which I am sure includes everything.


          • Clover, again I ask you are you a troll or an idiot?

            You cannot put LEDs into a bulb headlamp or taillamp assembly and have it work correctly. These are safety items, remember Clover? There are government (and private) regulations (and standards) that cover beam pattern, visibility at angles and distances, glare, etc and so on. Automotive lighting is a niche engineering discipline of its own. I picked up the basics from another discussion group ages ago from an automotive lighting engineer. He knows his stuff and you don’t know jack shit.

            Now if you want to put LEDs in your dome light, have at it. But taillamps and headlamps aren’t for you to read a map or something.

          • Brent would you go and do some research before you speak. Yes there are direct replacement for things like tail lights. Go and do a web search or search you tube. They are 12 volt and have the correct brightness required. I tried to provide a link but it was removed.

          • I know you’re a troll, but you’ve got to be an idiot too. Read my post again where I stated that such bulb replacements exist in the aftermarket, but they won’t work right. It’s not a question of bright enough, it’s a question of optics. That is putting light of the correct brightness where it needs to be while not where it shouldn’t be.

            Your crappy aftermarket bulb replacement LEDs might look just fine at night directly behind your car in your driveway in clear weather. However they may not work properly at 30 degree angle in the middle of a bright sunny day or at a 45 degree angle at night in the rain.

          • Brent all I can say is do some research. You are wrong on this one. LED lights are not a single led but multiple for each bulb. They surround the socket. They are visible what ever angle you view them from. I would appreciate it if you you spend 10 minutes doing research before you speak.


          • A troll and an idiot. It is clear you do not understand optics, even conceptually.

            The light emitted by a cluster of LEDs is not the same as a bulb. The lamp is a designed for a specific bulb type. Change the light source and the optics do not work as designed.

          • Tell us Illumination Doctor Brent, why is it that a globe of led lights is different than a normal tail light? They both produce light in all directions at a designed illumination level. Tell us the difference please. My thoughts are that the bulb should illuminate the lens and be very visible from any direction behind a vehicle. Tell us what is wrong with that Doctor Brent.


          • The differences should be obvious to even an idiot. However you are also a troll.

            Here is an 1157 light bulb:

            Here are some LED 1157 replacements:

            There are other configurations of these LED point light sources. The lamp they are put in is designed to a bulb with filaments, taking that light source and distributing the light appropriately. With several point sources grouped in various patterns it’s not going to work the same.

            Why do you suddenly want to take chances with safety Clover?

            • Brent,

              You ought to know better than to attempt to educate an optics expert such as Clover, who of course is also an ace mechanic, a pro driver, structural engineer, chemist, master of time and space….

          • Tell us Brent why they do not work the same? Believe it or not a filament is not one light source. It is around a half inch long. That is not one point of light source. That much I know. It is different so that is your educated reason? Not good enough reason for me.


          • I just realized I have a lot of extra parts for just about everything, except bulbs. Thanks for this thread! I’m going to stock up on some 192s and 1157s.

          • Clover, I already explained it to you.
            Here, this manufacturer of LED lamps describes that their lamps meet FMVSS 108.


            Notice how they are not selling bulb replacements, but replace the entire lamp with one designed fore LEDs.

            Here’s a diagram explaining a little about lamp optics:

            Why don’t you go out and find a LED bulb replacement that at least claims to meet FMVSS 108? Not an entire lamp, something that replaces the bulb in the lamp. Either that, or STFU.

            • I’d bet almost anything you’ll (per usual) fail to get a direct answer to your direct questions out of him/her/it. Clover will just segue off into new non sequiturs. You might as well try to nail Jell-O to the wall….

          • From looking at some of Brent’s links it looks like LED lights should be required. It said the visibility of the light is 2 tenths of a second quicker than standard bulbs. With the aggressive tailgaters we have on our highways today that have a following distance within a second, 2 tenths of a second is huge.


          • I told you about rise time several posts ago. Where’s your FMVSS 108 compliant bulb replacement LED modules? Don’t have one? STFU then.

  10. Yeah, but sealed-beam headlights are cheap because their design and engineering costs were amortized decades ago. And with modern technology, a sealed-beam is little more complex or difficult than a household light switch.

    If you tried to make a modern headlight assembly from glass, it would be even more expensive, not to mention heavier.

    I’m all for using composites and plastics for lightening the car. As long as they’re painted; I hate naked CF. It’s for ricers.

    I look at it this way: Once, steel and aluminum were grossly expensive specialty materials, but because they were used in more and more applications over time, the costs dropped, availability increased and people learned how to easily work with them.

    Carbon fiber, Kevlar and nanocarbon are no different.

    In my opinion, metals are nearing obsolescence as materials for dynamic structural applications. While they’re strong, they’re very heavy.

    Besides, if the modern trend is to make the car essentially disposable, it makes more sense to build the vehicle from composites instead of steel and aluminum. You don’t need a stamping press to mold Kevlar.

    I can manufacture a Kevlar or CF fender in my garage with mail-order materials and some ingenuity. I can’t make a replacement steel fender for my 850 without a house-sized stamping press.

      • Yeah, but just remember – the East Germans were Marxists, and the defining characteristic of Marxism is a shining inability to do ANYTHING correctly.

        I’m thinking more along the lines of F1 cars.

        • The engineers who came up with that little marvel were most certainly no marxists but living under a marxist system. When the Trabant came out in the late 50ies, it was pretty much state of the art for a small car (not sensationally good, (2-stroke engine, as they were not allowed to develop a 4-stroke by the russians) but not so bad either).
          That they did no development work on it for some quarter of a century because the Bolsheviks were broke by the mid-sixties is another matter altogether.
          When they were, in the late eighties, allowed to put a decent motor into the thing, it ran along at 180+ on the German Autobahn and handled nicely on normal roads – which tells you something about the quality of the overall concept. Ask the man who owns a souped up beetle (the standard free enterprise car in Germany, twice as large on the outside but not a bit on the inside) how that thing handles. By then however the image had been completely bombed out, and it did not compete against the Beetle but against the Golf and its likes, so a 4-stroke Trabant is a rare, if rather nice little car. If you get to Germany, try to find one for an afternoon’s ride, just to get a feeling of a 1950ies small an cheap car with some good ideas put into it.

          • I’ve never actually driven a Trabby, so I can’t comment from personal experience. But I have driven a Yugo GV – another fine product of East Bloc collectivism – and that thing was an epic POS!


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