Ive heard that bar and plate was more effecient because a smaller bar/plate can do the job of a larger tube fin just as efficiently, but Ive heard tube/fin flows better. Then I read the complete opposite on wrx performance website not to long ago. Im just looking for little clarification between the differences in performance and construction of the two.
Andy, this is from the NZ Supra site tech section, hope you find it useful:
There are two core types for air-to-air intercoolers and they both have their advantages and disadvantages. The BAR & PLATE type has more pressure drop and a lower flow rate but usually has a higher efficiency. The TUBE & FIN type has less pressure drop and a higher flow rate at the expense of a lower efficiency and will be the lower priced of the two. The factory mkiv intercooler is a TUBE & FIN design.
There are so many different opinions on which is better. You will have to decide for yourself. Both are proven so you really can't make a bad choice as long as the intercooler isn't made out of cheap material. I'm going with a Garrett bar and plate intercooler core with Precision end tanks.