Your OEM plastic fails, our's doesn't. If you've been a BMW enthusiast for some time, you know that the N55 expansion tank is a known weak point of the car. So, we did what we do best, and our Turner engineers put in the work to develop an improved expansion tank! Built to take the heat, pressure tested, TIG-welded, and designed for a factory-perfect fit, this kit adds durability without compromising your daily drivability! Upgrade your N55 with confidence and search T30031522 to erase any fears of your expansion tank cracking or worse! #turner #turnermotorsport #tms #turnerbmw #bmw #n55 #n55bmw #expansiontank #bmwthings