Ford Focus ST Expansion Tank 2013+

I told you this project was going to move fast. In the last update, we laid down our design plans for how we will give this RS coolant expansion tank some sprucing up. Not only did we make the tank more pleasing to look at, we also increased the capacity and added a neat sight tube so you can check your levels with ease. You guys have been asking for it, so let's get up close and personal.

The stock unit pales in comparison to the size of the Mishimoto tank.

One of the first things you'll notice with this tank is the capacity increase over the stock unit. We are making this tank to fit both the Focus RS and ST, but that doesn't mean we have to stay within the size parameters of the stock unit. The stock expansion tank holds a maximum of 1.56 liters of fluid. Our design more than doubles that, with a maximum fluid capacity of 3.58 liters. With the increase in capacity comes an increased chance of fluid sloshing inside the tank during hard driving. To combat the extra fluid's movement, we

Anyone with a car older than 15 years or so likely has a coolant expansion tank with the structural integrity of wet toilet paper. These tanks rarely get aesthetic love in the factory vehicle design. They are usually plastic, look weird and can start cracking given enough time. After 20 years, the expansion tank in my 1995 Nissan 240SX project car will literally begin crumbling around your finger if any sort of pressure is applied. We don't want that happening to your RS/ST a decade or two from now, so we decided to design a sweet looking expansion tank that will outlast the car and be a nice addition to your engine bay.

The stock cap on the RS has a pressure limit of 21psi

Factory expansion tank for the ST

There is a lot of focus (I haven't made that pun in a while, give me a break) devoted strictly to improving how this EcoBoost hot-hatch platform performs since it's introduction. This is important, our engineers have that as a clear goal in their minds. For our RS, we've released an