What are the pros and cons of plastic cars?
by wcunning - 6/6/07 1:57 PM
In my recent column, The plastic transparent car, I wrote about increasing use of plastics in car body panels. Would you buy a car with a plastic body?
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by: wcunning June 6, 2007 1:57 PM PDT
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They are, but for a different reason.
Mazda's rotary is more efficient. But the reason is because of smaller size. Since each rotor acts like three pistons, you have a two rotor engine being able to produce the power of a V6. A three rotor engine likewise produces the power of a 9 cylinder engine (which does exist, but this is the equivalent).
The key being, a rotor takes a lot less space than three cylinders. Thus a 1.5 liter rotary is so much smaller than a 3.1 liter V6, yet produce the same power.
The efficiency then comes from less weight and smaller size. Of course in the equation power to move weight times speed, if you reduce weight, and leave speed and power the same... that's more efficiency.
Sadly, the rotary is no better at extracting more mechanical force from an amount of fuel. In fact, without turbo charging, it gets less. This is because it is harder to get the compression you need with a rotor.
modern planes may very well be made of composites but also cost how many millions to produce???? when cost is no object you can do a lot of radical things with exotic products. throughout WW2 and beyond a lot of planes used cloth in their construction. so does that mean we should also have cloth covered cars??
Frankly if the plastic is durable, UV resistant and offers the same protection as metal, and repair costs are the same, I would prefer plastic. If plastics ever have the same characteristics as carbon fiber I would pay extra for a car containing large amounts of these plastics paired with a powerful engine. It is pounds per horsepower that is the most potent factor influencing acceleration and top speed. The Lotus which is one of the lightest cars being produced can outrun cars with almost twice as many horsepower. Almost all motorcyles which are relatively light can go 0-60 in 4 seconds or less. Only very high performance cars perform like this because of their massive weight. Using more quality plastics would increase performance as well as gas economy.
Plastic bodies are good, but give me a steel chrome bumper
I like the light weight plastic bodies. I had a 58 Chevy Impala one time, a beautiful car, but I couldn't keep the fenders from rusting out around the headlights. Eventually, somebody sold me a fibre-glass fender. When the car eventually went to that big parking lot in the sky, there wasn't mush left to most of the body, but it sure had one nice fender. So I like the plastic because it doesn't rust.
I don't want it to be brittle in severe cold. Hey it gets pretty brutal on the Canadian prairie or the northern American mid-west.
But please, give us chromed steel bumpers again. You can actually use them for something, like pushing another vehicle if it is stalled. Also, if you lightly bump an immovable object, a plastic bumper may be destroyed while a chrome bumper just needs buffing with a soft cloth.
Get real - race cars have been made of fiberglass for most readers' lifetimes - and safety not an issue because of plastic - the frames and body safety design do all the work.
Plastic is durable, also burns!
There are pros and cons about all types of cars today, and I enjoyed driving a 95 Saturn SL2 for eleven years until the metal parts just gave up on it. The one incident that made me shudder was to see the results of a highway accident when two very modern cars hit headon, with one bursting into flame after impact. All the plastic burned so totally that all was left was the frame and a ten foot diameter black spot on the road! I'll stay with metal bodied cars as much as is possible, thanks!
Plastic cars are junk and your missing the point
At 62, I have owned a lot of cars. I have been in various forms of auto racing all of my life. I believe in all of the safety features because I have had the accidents before the rules required the various devices including safety belts. Having a car safe enough to with stand a crash at 200 MPH is great, believe me. On the street, the rules don't change, just the speed. At 35 MPH, you don't need a car to collapse into a pile of rubble to be safe.
Several years ago I put my wife in a 1986 Jag. It's a tank at 4975 lbs. She has been sitting stopped at a traffic light and was rear-ended by a Lexus SUV. She drove off with no damage. The Lexus was totaled. She was t-boned recently and got the wreaker driver to change the damaged wheel so she could drive home. The other car was totaled. She has never been hurt.
I still wish I owned the 1980 Buick I use to own. It was the small one, but it had the 35 MPH bumpers like my wife's Jag. Over the 18 years I owned the car, I was rear ended 8 times and never had to repair the car. But that's Houston traffic and I am not out to support auto manufacturers by buying a new car every time someone hits me.
I have been a geek since 1960. I always try new stuff. I have given up on plastic cars because I hate the noise these things start making after you hit one pot hole. Maybe if I lived in a small town and did not have to worry about the other driver and my bank balance, I might try again. But as long as Congress, the insurance companies, and the auto companies are playing games to get our money, I will have no part.
All you need to do is look up a little history. 40 years ago cars stopped from 60 MPH in 110 to 120 feet. Today they take more distance with anti lock brakes. 25 years ago cars with stood 35 MPH impacts without damage. Today they are totaled. It's all about your money.
All the current solutions are stupid. Everything can be recycled, except fuel. Alcohol just makes ADM rich and drives up the cost of food. I used to travel to Brazil where they have used alcohol for years. Rush hour traffic will choke you. It's all about your money.
I don't want to destroy the Earth. I want my grand children to have children of their own some day. But unlike our leaders, we use mass transit for trips, live close to our work, and just don't drive that much to save. Common sense is the thing that's missing.
Common sense is the thing that's missing.
"Common sense is the thing that's missing." Amen brother AMEN!!!
Editers Choice of Hybrid vehicles
I thought that hybrid technology was to reduce the carbon footprint.
Then I read the editers choice of hybrid vehicles. Over half of your top picks would cost me more than I am spending now for 12000 miles per year, and I drive a Towncar that gets about 22 miles per gallon. But of course your picks, for the most part, were mostly of the higher priced luxury hybrid vehicles. But then I drive a higher priced luxury vehicle so why would I buy one of your picks when it will cost me mileage? Wake up and pay attention to what you are picking, your choice in this case was not to bright. Unless your picks were just to keep up with the Jones...
Plastic Cars - not in my plans!
Ever had a small rub to your car in a parking lot, where some jerk backed out of a spot and scuffed up your paint work?
I just purchased a brand new vehicle and just had this experience.
I was able to polish out the damage to the metal bodywork with very little effort.
But it was a different story with the rear plastic bumper - there is absolutely no chance any scuff marks can be removed.
I also feal that normal wear and tear, weathering etc and suns rays will deteriorate the external finish of plastic.
My vote is no to plastic - Let the Chinese continue to use this for production of cheap Christmas time stocking stuffers!
there are cars out there now that are made with plastic panals , saturn and the smart to name a few. If they use aluminum of some metal that dont rust for the unibody ,up here in the north that would be the car, i just send a Honda to the salvage yard cause it rusted all out,theres no safty in a rusted out car it makes the whole car a crumple zone , or is there a resale value . On you tube there is videos of the smart in crash tests up to 60 mph . i think it would be a good ideal to use plastic or materials that is not susceptible to corrosion ,and if they add crumple zones so the car takes the inpact not you . lighter materials would be a plus better gas milage , but not so light that normal prairie winds would be a hazard to control.
I drive today the same car I drove 38 years ago.
Solid, reliable, in overfdrive 26MPG.
Finally put a new motor in after 300K.
Has over 500K on the clock.
You can see stuff under the hood and work on it.
I was in auto repair for 35 years, I wouldn't own plastic or import.
And as a bonus, no stinking computers!
Plastic or sheet metal for passenger cars ?
Combination is best. Example 1987 Jeep Wagoneer.
20 year old Wagoneer still looks good as anything on the road today. For Proof in a good sized photo see:
The Wagoneer has plastic fender lip trim. This little 4 cylinder bounce around town Jeep is finally getting tired out at 240,000ks. Starting to burn a little oil.
This never was a freeway vehicle and the ride is * harsh alert*. Still, it is always reliable and the lack of any serious rust must be the result of careful deluxe assembly and undercoating.
What would a Lexan / Perspex / plexiglas roof look like after 20 years? Would it have leaking cracks from temperature extremes? Would it look like hell due to thousands of scratches? Would it have gone all cloudy and dingey looking?
Did the limited use of fender trim plastic keep this Jeep from rusting around the fenders?
Should I put a new engine in this Jeep? [$$]
Should I do a PEV conversion? [$$]
How about a [ made in France],compressed-air motor conversion.
Refuel with 2 hours of nightime air compression to a 4,500 PSI tank.
Think of it as a steam engine wihtout heat or steam.
The French are exporting thousands to India and they run air-pressure Taxis in Paris. [ Photo on my blog ]
Plastic cars are a dubious wait and see thing for me. = TG
Stops rusting nicely, but resiliance in other cases is iffy.
Pros: Less opportunity for corrosion. If the paint gets a scratch, chip, scrape, it's not going to rust. So on most cars with a plastic body or lower body panels, "death from car cancer" is practically a thing of the past. Typically everything else will wear out before the body goes (look at old Saturns for instance.)
Cons: Most automotive plastics have limited give or are composited with another more rigid material. So if you bang a car into something too hard it will crack or tear. (Unfortunately the 5mph resilient bumper is no more.) So things in the past which would have merely caused a dented bumper or panel (if that even) now necessitate replacement of the entire piece. Replacement panels aren't cheap, typically over $500 U.S. Also if the plastic is a composited with another material such as fiberglass it can't be easily recycled if at all. If repaint work is done on a car with mixed plastic and metal body panels, sometimes the paint doesn't match 100% due to the different qualities of the plastic and metal primers.
by whitegreyhat - 6/20/07 10:58 PM
In Reply to: Stops rusting nicely, but resiliance in other cases is iffy. by pauljs75
The types of plastics which are going to be used in these cars are high quality polymers. These engineers are not stupid. Where do you think Kevlar comes from (polyarylamide), the answer is plastics. In case you don't know what that is used for, it is used for making bullet proof vests, and other bullet proof applications. We aren't talking about making a car out of last years unsold Christmas ornaments. People get this idea of plastics and automatically start to think about the Pintos and Geo Metros. It is not the same thing, very rarely is a typical consumer like you going to see the actual potential that plastics have for actual practical use, because of the fact that it is very expensive at this stage in development and the other reason is people don't want change. They hear plastic cars and immediately become paranoid about being "disintegrated upon impact" or "zapped by lighting" as i saw in previous posts, have some faith in the future...
Plastic vs metal
OK; Good points raised by all. Carcinogens? Bad. Lightweight, ding resistance,recylable? Good! Safety? Mixed bag depending. Look at the A-1 race cars. Very light weight, but the "cockpit" area is very safe and detachable in case of smashups. Same theories should apply to any passenger vehicle. Corvette is a prime example of a private car that uses some of these ideas. Fiberglass panels, X-frame, side protection etcetera. I've seen Stingrays that looked like an unassembled Japanese action toy...hundreds of pieces, but the driver pod almost untouched and the driver? Still alive to tell a harrowing tale.
Bottom line is the maximum safety/economy/environmentally friendly unit we can build, NOT the easiest, cheapest, most profitable piece of eye-candy we can get away with.
Retro in China
i own a plastic car
My 1986 Popntiac Fiero GT is made of three types of plastic. The roof,hood and trunk lid area hard plastic for strength andthe fenders and door panels are a flexible type the same as on a Saturn. The front and rear bumpers are soft flexible plastic with flex paint so it will not crack in minor hits. This plastic car is the most fun car I have owned.
I would just not buy a car.
If all are worried about carbon footprints on the sands of limited time, then why buy a car at all. Use the old Dodge Dart until it's rust and dust. They go public transport or scooter/motorbike/mountain bike. Move closer to work so you can walk. Change your lifestyle to save the planet. There is not much time left. Ask a polar bear.
Carless in Nepal
Pity I cant download photograph for you to see a bus the alloy manels melted but the fibreglass is still in situ..
magnesium is one of the only metals i know of that would burn like what you describe. i know there are others but that is one very commonly used. even with a fire like that the fiberglass would be just a crust. the polyester resin in fiberglass will burn and/or melt but the spun glass fibers will stay pretty much intact.
"Both And" is the real answer, IMHO.
I favor the increased use of plastic materials in auto construction. Where ever the materials make sense use them. Materials Science and Engineering is a steadily evolving art/discipline, and new uses of old materials, as well as new materials altogether are constantly being brought to the marketplace.
The only major downside of plastic materials are their susceptibility to become involved as fuel in any fire events. That may also produce a toxic or at least noxious gas as well. There are ways to mitigate and control that danger, but at some tipping point where most (or at least most of the surface) of the vehicle is plastic that danger may become more serious.
The other trend which I favor is the use of more alloy, esp. Aluminum alloys, in certain parts, e.g. wheels, major & minor castings, engine blocks, Tranny cases, etc.
All of that should add up to a lighter and more efficient vehicle requiring less horsepower to motivate, less braking to halt, and increased duty-life cycle for major subsystems and the vehicle itself. Engines are so much better now than they were, even by the late 1970's, that few people, other than car restorers, even realize how poorly conceived and made all engines from 1900 to the early 1970's really were!
Modern injection sytems, engine management computers, and distributorless ignitions are far superior to all that ever went before. The use of specific alloys at various points inside the engine itself have reduced weight, increased reliability, and made closer tolerances possible. This allows modern engines to produce a great deal more torque and power from smaller displacement engines without having the increased internal stresses reduce engine life. In fact, a well maintained modern engine often lasts more than twice as long, between major breakdowns or overhauls, than any enigne produced in the 50's and 60's. Few people ever own a vehicle long enough, any more, to replace either valves, rings, or bearings. That was not the case for most of automotive history before the past twenty years.
I had seriously thought that by this time we would be siing the use of high-temperature, low brittleness ceramic components inside our engines. I don't know what the current status of the development cycle on those items is, but I recall the prediction that items like that would eventually turn up inside the combustion chambers of engines with positive results.
If you are an automotive engineer invovled all that has happened especially since 1980, feel free to pat yourslef on the back for the thoroughgoing evolution you have put the auto through since you began work.
JB is firstname.lastname@example.org
Bend your mind around the new concept.
Living in a state that salts roads in the winter, I can think of at least one big pro to a plastic bodied car. As far as safety, it may be time to reconsider the turtle model. Do people wear steel helmets when riding motorcycles? No, they're fiberglass and plastic foam. Bicycles, even lighter...styrofoam with plastic mesh reinforcing and a thin plastic shell to protect and smooth the surface. It's cheap, it's light, it does the job. As far as recyclable, anything is recyclable with the right technology. I hunt for stores that take plastic grocery bags for recycling and stuff their barrels with bags I get from my own shopping, my family and friends.
I like the plastic bodies in my Saturn cars.
I bought my first Saturn car in 2000 because I need a car for tight parking spaces without worrying about dents. My 2000 Saturn LS2 serves me well for that purpose. I since bought two more Saturns, a 1996 LS2 for my daughter and a 2005 Ion2 for my mother-in-law. There is not a single dent in the plastic bodies. On the other hand, my 2002 Honda Odyssey has several dents including a nasty one on the right fender near the wheel-well. I think for city driving and parking, nothing beats plastic body panels.
Not if I can help it...
In late May I was coming home late as the bars were closing and a patron of one of the bars pulled out in front of me with so little time that all I could do was attempt to dodge his extended cab long bed pickup. I got as far as the corner of the truck bed.
I was driving a 1974 Super Beetle. The front end of the car was crushed, but the force of initial contact of the car to the truck dissipated enough energy to save my life and the paramedics were able to pull me out through the passenger side door after getting it open. The car from the doors back looked fine, although there was enough twisting of the frame of the car to make opening the driver's side door impossible, and the passenger side door stuck unagreeably but could be opened.
I believe had I been in the beer can cars of today in any equivalent size as the bug, I wouldn't be here to type this reply. I suffered 2 broken ribs, probably whiplash, probably torn meniscus of my right knee, and a deep laceration to the bone on my left outer elbow. I impacted the steering wheel with my central jaw, driving a partial lower plate through the skin below my lower lip. It was not pretty, and the other driver was taken to jail for DWI and also given a ticket for failure to yield.
I can't imagine a 'steel cage' absorbing this impact and still leaving me enough room to live through the wreck. The ribs and lower lip would have been protected from the steering wheel ONLY until the cage was crushed inward enough to collapse upon my survival space.
I was driving only 35mph, it was a downtown street but on the outskirts of town, and as far as I can tell, I never had a chance to hit the brakes. I can't say for sure because after the impact I was unconscious, probably with a concussion, until the paramedics pulled me from the car. I ended up with a hole in my memory, there's no 'tape' to 'playback' of the wreck. The 'tape' starts when the EMS guys are trying to reassure me while trying to figure out how to get me safely out of the car. I have a picture of the bug, but no way to share it here unless you contact me and make special arrangements. The car was almost completely restored, new motor w/less than 10K on it and less than 6 mos old, new front end, macphearson struts, tires, the car was in top running shape and ready for new paint and interior. Now it is a twisted piece of sick modern art.
Plastics are still plastics....
Plastics??? You gotta be kidding. Back in 1976, when I accidently reversed into a lamp-post in the dark of the night, the post tilted 15 degrees. No damage was done on my Fiat 132 chromed STEEL bumper! Not even a dent! Try doing that today with your "modern" safety-oriented car! Sigh! Bring back the good ole times!
You've got to be kidding. There is such a thing as economizing too much. What kind of protection is a plastic car going to provide to a driver or passenger in a collision? What is going to be the weight factor of plastic cars? The higher the speed, the more air resistance there is, and I'm currently having visions of plastic cars veering off the road whenever there's a healthy gust of wind. A YUGO would seem like a luxury limousine compared to a plastic car. What a silly idea!
It would be nice to have a vehicle constructed with memory plastic. If you bang it up a little bit of heat would make it spring back good as new!
UNSAFE AT ANY SPEED
This discussion reminds me of the French sportscar Renault Alpine, I drove in Germany. The car's body was made entirely out of plastic, even the luggage compartment - at the front of the car - was made of impregnated cardboard. The tires were extra-wide, resulting in a stark reduction of pressure per square inch, and thus reducing the car's ability to withstand aqua-planning.
Indeed, in June of 1990 - at a speed of under 60 mph - the front liftet off, the car started spinning, non-reactive to any counter-steering attempt, eventually hit the guard rail, at which time it dissolved itself in its parts. My head hit and broke the side window and I was out for 15 minutes.
That experience taught me to stay away from cars that have been designed by engineers who have not a clue of the consequences of their efforts to make cars lighter, for whatever reason. Saving gas? Yes! Toyota has the right idea.
who are you kidding
I think that both the tin cans and the plastic cars are death traps. I don't want any of the newer cars or trucks. Give the older models anytime. I've recently been involve in an accident that had I been in either the tin-cans or the plastic cars I don't think I would be here to give my opinion. I tried to avoid a tractor-trailer making a U turn in the middle of the highway. I wound up hitting the trailer. I totaled my 88 Eagle Premier but my son and I only suffered minor injuries. bumps and bruises and a few cuts. had I been in a tin-can or plastic car then I would have wound up with the engine in my lap and the trailer in my face. If you want to risk that then you take the tin-cans and the plastic. I want METAL around me for some protection should something like that happen to me again. Thank God for the protection of good old fashion METAL
All very well, but people need to be aware of limitations
Making cars lighter obviously increases fuel efficiency. There the benefits end as far as I'm concerned. If you've ever seen a regular (steel) sedan car that's gone up against a Ford F350 pickup (of which there are many where I live) you'd think more than twice about driving a little plastic car. Little plastic cars are only safe if everyone drives little plastic cars.
In Europe, many cars have plastic body panels as well as the bumpers. I've seen the results of someone hanging a bike rack from the rear hatch of a popular French car - While driving along a freeway, the fiberglass simply tore away at the point where the rack was hooked on, dumping the unfortunate owner's expensive bicycles in the path of oncoming traffic.