When it comes to optimizing your diesel truck, FASS Diesel Fuel Systems are an obvious choice.
But if you’re exploring their product line, you might encounter two distinct options: the “ No-Drop ” FASS Diesel Fuel System and the “ Drop-In ” FASS Diesel Fuel System. While both will deliver the purest fuel possible, and protect your investment, they offer slightly different benefits and features.
Let’s break down the key differences to help you decide which FASS system is right for your rig.
The FASS Fundamentals: What Both Systems Deliver
Before diving into the distinctions, it’s important to remember what both No-Drop and Drop-In FASS systems offer:
- Superior Fuel Filtration:
Both systems significantly improve fuel quality by removing contaminants like water (over 99%), air/vapor, and particulate matter down to incredibly small levels (2-micron absolute filtration). This protection is vital for modern, high-pressure common rail fuel systems.
- Extended Injection System Life:
By delivering cleaner fuel, both types of FASS systems can TRIPLE the life of expensive fuel injectors and injection pumps—potentially saving you thousands on costly repairs.
- Improved Performance: Cleaner fuel leads to more efficient combustion, which can result in optimized fuel economy, restored horsepower, and sharper throttle response.
No-Drop FASS Diesel Fuel System: The Complete Fuel System Overhaul
The “No-Drop” FASS Diesel Fuel System is exactly what it sounds like: a comprehensive fuel system upgrade that doesn’t require dropping your fuel tank for installation.
This is a significant advantage for many truck owners, as removing the fuel tank can be a time-consuming and labor-intensive process.
Key characteristics and benefits of a No-Drop FASS System:
- Complete Fuel System Replacement:
A No-Drop Kit combines a FASS Titanium Signature Series Fuel System with the FASS Fuel Sump Kit. This means it
replaces
your factory in-tank fuel pump, offering a complete upgrade to your fuel delivery and filtration.
- Increased Fuel Flow:
Because it includes a dedicated FASS lift pump, the No-Drop system provides significantly more fuel flow than your OEM (Original Equipment Manufacturer) fuel pump.
This is particularly beneficial for trucks with performance modifications that demand higher fuel volumes. Flow rates can range from 100 GPH (gallons per hour) up to 290 GPH.
- Simplified Installation (No Tank Drop):
The integrated fuel sump kit allows you to drill a single hole in your fuel tank and bolt in the sump, bypassing the need to remove the entire tank to access the factory fuel module.
This saves hours of installation time.
- Ideal for Higher Mileage or Modified Trucks:
If your truck has higher mileage and your OEM fuel pump is nearing the end of its life, or if you’ve added performance modifications (like larger turbos, tunes, etc.) that require more fuel, a No-Drop system is the ideal choice.
It ensures your engine receives the precise and ample fuel supply it needs.
- Cost-Effective as a Bundle: Often, purchasing a No-Drop Kit (which bundles the Titanium Signature Series system and the sump kit) is more cost-effective than buying the components separately.
Drop-In FASS Diesel Fuel System: The Plug-and-Play Filtration Solution
The “Drop-In” FASS Diesel Fuel System takes a different approach. Instead of replacing your entire fuel pump, it’s designed as a simple, plug-and-play filtration upgrade that utilizes your existing stock fuel pump .
Key characteristics and benefits of a Drop-In FASS System:
- Enhanced Filtration, Retains OEM Pump:
The primary function of a Drop-In system is to drastically improve fuel quality by adding FASS’s superior filtration (2-micron absolute), and air/vapor removal, and water separation to your existing fuel system. It works in conjunction with your factory in-tank lift pump for fuel flow.
- Easy Installation (True Bolt-In):
Drop-In systems are renowned for their simplicity. They typically bolt into a factory mounting location and connect directly to your existing fuel lines, requiring no cutting, wiring, or drilling into your fuel tank. Many can be installed in an hour or less by a DIY enthusiast.
- Ideal for Stock or Lightly Modified Trucks with Lower Mileage:
If your truck is relatively new, has lower mileage, and is mostly stock or has only minor performance modifications, a Drop-In system is an excellent choice. It provides the essential benefits of FASS filtration without the expense or complexity of a full pump replacement.
- Cost-Effective Entry Point: Drop-In systems are generally more affordable than No-Drop Kits, making them a great entry point into the world of FASS fuel filtration.
Which FASS System is Right for You?
The choice between a No-Drop and a Drop-In FASS Diesel Fuel System boils down to your truck’s current state, your performance goals, and your comfort level with installation:
- Choose a No-Drop FASS System if:
- Your truck has higher mileage, and you’re concerned about the longevity of your OEM fuel pump.
- You have performance modifications (or plan to add them) that require increased fuel flow to the engine.
- You want the absolute best in fuel delivery and filtration, with a complete replacement of your stock system.
- You prefer an easier installation process that avoids dropping the fuel tank, even if it involves drilling a single hole for the sump.
- Choose a Drop-In FASS System if:
- Your truck is relatively new or has lower mileage, and your OEM fuel pump is still in good condition.
- You’re primarily looking for improved fuel filtration and protection for your injection system, without needing a significant increase in fuel flow.
- You prefer a truly plug-and-play installation that can be done quickly and easily, without any modifications to your fuel tank.
- You want a cost-effective way to get FASS’s legendary fuel quality benefits.
Ultimately, both FASS No-Drop and Drop-In systems offer substantial benefits for any diesel truck owner. Understanding their core differences will empower you to make the best decision for your vehicle and ensure you’re getting the most out of your diesel engine for years to come.
The post “No-Drop” and “Drop-In” FASS Fuel Systems—what’s the difference? first appeared on FASS Diesel Fuel Systems | In God We Trust.
