Originally Posted by BlackFighter
The oem one is plastic on top. The koyo is all alum thay getts much more hot on top then the oem plastic one.
It doesn't get any hotter than the plastic end tanks but since aluminum transfers heat faster than plastic it also transfers heat faster to your hands when you touch it giving you the impression that it at a higher temperature. It is not.
Do not confuse temperature with heat and/or the transfer of heat. They are different.