Quote:
Originally Posted by ROLLGUY
I needed to replace the radiator in my brothers '05 E320 CDI W211, so I ordered and received a Spectra Premium unit. To my surprise, it has only one row of tubes. The factory one had two. I can't see how manufacturers can sell a radiator with half the cooling capacity. The description says "Unit is designed to original equipment (OE) fit, form and function requirement".
It looks identical, so it should fit just fine. It is the "function" aspect I am concerned about. I just wonder if I should send it back and get a two row (Nissens or Valeo).....Rich
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There's a lot of crap out there, but your assumptions are bad. The question isn't only the number of tubes, it's the size of the tubes as well. And fin design makes a big difference. Some of the worst radiators have four or more tubes and very dense rows. More is not necessarily better. Unfortunately, the only way to know is to try it.
What's important is how much tube/fin contact area is created, how restrictive the air flow path is and how turbulent the air and water flow are. Lately, I've been competing against insanely cheap Chinese radiators which invariably come with four small rows. My radiators have two rows. But in a comparison between four 3/8" tubes and two 1" tubes, the 1" tubes give measurably bettter performance. See the drawing below to understand how fewer can be better. The problem is that the ends of the tubes make poor contact with the fins. So fewer, bigger tubes have more contact area. It may seem to be a small point, but it makes a big difference. Additional improvements can come from corrugated fins and turbulators in the tubes.