Frequently Asked Questions (FAQ)

Do the FASS kits include everything needed to install them? What about Class 8 kits?

The majority of our kits are vehicle specific and come with all parts needed for installation. The Class 8 kits require a fuel return line kit to complete installation (visit to see the complete line of fuel line kits).

I have purchased one of your units, how do I receive the extended warranty?

After purchasing from a registered or authorized FASS dealer it’s essential to complete the 1st page (front and back) of the installation manual within 30 days and mail to address below with a copy of your receipt or visit to register online.

Diesel Performance Products, Inc.
16240 Hwy O Suite B
Marthasville, MO 63357

Can I install the FASS system myself or does it need to be installed by an authorized FASS installer?

FASS is continuously updating and changing our units to make them easier to install for the end user. As long as you take your time, read and follow the provided installation manual, installs can be completed by the end user. If you have any questions, please don’t hesitate to call our staff of knowledgeable customer service representatives.

Will my fuel mileage increase?

After the installation of the Titanium series unit, our customers have reported 2-3 mpg increases for pickups and .4 mpg increases for Class 8. While this is an average, FASS does not guarantee fuel mileage increases.

Am I required to use FASS filters on the Titanium series unit?

FASS realizes that in emergency situations you may not be able to find FASS filters in time. For your convenience, at, we have provided a list of cross reference filters available at auto parts stores and full service truck stops

Does FASS void factory manufacturer warranties?

No, FASS does not void factory manufacturer warranties because our products meet their filter specifications.