Why do car radiators have plastic tanks?

[Steve S]

Originally Posted By: swalve
Yet, with all this "cheap" plastic, cars last longer than ever. And more reliably.

The material isn't the issue, the design is.
No they don't. You are mistaking newer technology vs quality there are better plastics seal material the oils are way better there is lead free gas which is way better and probably the most important are the emission laws. The newer cars are throw away tin cans.

 

[parimento1]

yes some of the emission laws are to blame, mainly fuel economy. In an effort to make cars lighter to maintain fuel economy everything has become paper thin and cheaply made. Do you think engine with aluminum blocks and heads would be put in regular passenger cars had it not been for CAFE? Cast iron is much cheaper yet more durable than aluminum; but it is heavier. At least auto makers are working on making these disposable cars recyclable just like tin cans! I hope I get my 5 cent deposit back when I finally junk my car lol.

 

[PandaBear]

Originally Posted By: parimento1
yes some of the emission laws are to blame, mainly fuel economy. In an effort to make cars lighter to maintain fuel economy everything has become paper thin and cheaply made. Do you think engine with aluminum blocks and heads would be put in regular passenger cars had it not been for CAFE? Cast iron is much cheaper yet more durable than aluminum; but it is heavier. At least auto makers are working on making these disposable cars recyclable just like tin cans! I hope I get my 5 cent deposit back when I finally junk my car lol.


You probably get more than 5c in the fuel saving compare to a 5000lb tank your dad was driving.

 

[TomYoung]

I am having a tough time believing that this is even a question. Are we talking about plastic overflow "tanks" or the plastic components on radiators? Either way, new radiators, with their plastic parts area heck of a lot more reliable than the all metal parts of old.

Why? Well for the same reason you have rubber hoses connecting the rad to the block and because they prevent electrolytic interaction. Leave the metal parts for what they do best - conduct heat to fins and into the air. I have driven 3/4 million miles since replacing my last radiator, all metal, on a '76 chevette.

 

[John K]

with the price of brass and copper you might find someone stealing your radiator for scrap! I think corrosion resistance of plastic is also a big plus.

 

[Gary Allan]

Originally Posted By: TomYoung
I am having a tough time believing that this is even a question. Are we talking about plastic overflow "tanks" or the plastic components on radiators? Either way, new radiators, with their plastic parts area heck of a lot more reliable than the all metal parts of old.

Why? Well for the same reason you have rubber hoses connecting the rad to the block and because they prevent electrolytic interaction. Leave the metal parts for what they do best - conduct heat to fins and into the air. I have driven 3/4 million miles since replacing my last radiator, all metal, on a '76 chevette.


You have rubber hoses due to the total lack of suitability for rigid piping in that scenario. It's the same for your air conditioning, power steering...whathaveyou ..the plumbing interface is flexible since the engine and the frame aren't integrated. Designers would be thrown a good curve ball in the usage of such things, I imagine. If it was more sensible to have rigid piping ..ABS or Nylon would be used if galvanic interaction was important.

I've never had a metal tank "fail". I've had a hole poked in it ..and it was easily repaired. Now cores ..surely ..but with metal tanks it was always customary to just recore the rad. Now with plastic tanks ..while there is an evolution to actually servicing them, they're throw away items for the most part.

I'd say that IF you really maintain your cooling system ..especially with the mixed alloy engines of today, you "may" get enough life out of the rad/heater core.

..but ..when the tank seam goes bad on another plastic tank rad ..what do I blame it on??