Tech Time-Radium Fuel Filter Upgrade for 16+ Ford Focus RS

Did you know that the Focus RS has a serviceable fuel filter? Have you serviced or upgraded your fuel filter? Did you know that manufacturers recommend serviceable fuel filters be replaced every 20k-40k miles?

If you answered "No" to any of these questions you may want to keep reading, as we have some valuable information on how an Upgraded Fuel Filter can make a difference on your Focus RS.

One of the many differences between the MK3 Focus ST and Focus RS is the fuel filter. Ford outfitted the RS with a serviceable fuel filter that is placed beneath the car, neighboring the fuel tank. The OEM filter media was chosen without careful consideration of what owners would be doing with their RS. The OEM filter just doesn't cut it when it comes to high horsepower applications and alternative fueling such as Ethanol. The OEM filter is also very restrictive and the effects of this can be greatly increased the longer the stock filter is in place. Luckily for you, there is a simple and proven solution from our friends at Radium Engineering.

The Radium Engineering Fuel Filter Kit can be installed at your home garage in approximately an hour with basic tools. To make the process even simpler, Radium has supplied instructions for install which can be found here. 

When comparing the Radium filter to the OEM Filter, it is far less restrictive. The Radium filter puts less stress on the fuel pump, roughly 3-5.5psi less than OEM. Lower pre-filter pressures will draw less current and lower fuel temperatures while increasing fuel flow.

The red marks above represent one aftermarket pump and the purple marks denote 2 aftermarket pumps. Note that there is a 2% and 4.5% flow increase, respectively.

Radium offers 3 different elements for their fuel filters inlcuding Cellulose, Microfiber Glass, & Fine Stainless Cloth. All filters mentioned are maintenance-free, however, the cellulose and Microfiber glass options are not reusable. The Stainless options can be cleaned in an ultrasonic solvent bath, or with carb cleaner followed by a light air blast from the inside out every 10k-15k miles. 

All are great options over stock, however the graph above proves that not all filters are made equal.

Our recommended filter would be the Fine Stainless Cloth option due to it being reusable, providing excellent flow & filtration, and compatibility to alternative fueling. On top of that, it would be the last fuel filter you would need to buy!

To pick up a Radium Engineering Upgraded Fuel Filter system for your Focus RS, follow the link here.