-8AN 100 Micron vs 40 Micron Fuel Filter: Which to Choose
By DeatschWerks | Published: 2026-10-30
Category: Comparisons
Compare DeatschWerks -8AN 100 micron and 40 micron in-line fuel filter kits. Learn which micron rating better protects EFI injectors without starving high-flow pumps.
Quick Answer
Choose the 40 micron filter for EFI systems that need finer protection, and the 100 micron filter for high-volume or pre-filter applications where flow is the priority. Both DeatschWerks kits share the same -8AN 160mm housing, so the decision comes down to your fuel system's tolerance for particles.
Micron rating trade-off: protection vs flow
The micron rating tells you the largest particle the filter will trap. A 40 micron element catches finer debris than a 100 micron element, which is why it's the safer choice for sensitive EFI injectors. However, a finer filter can create more flow restriction as it loads with contaminants.
Both DeatschWerks kits are rated for 1000+ lph flow, so at a clean state neither should starve a typical high-flow pump. The practical difference appears over time: the 40 micron element will clog sooner in dirty fuel, while the 100 micron element offers a longer service interval.
If you're building a street EFI car with stock or moderately upgraded injectors, the 40 micron filter gives you peace of mind. If you're feeding a high-horsepower setup with a massive pump and need maximum flow margin, the 100 micron filter is the safer bet.
Housing and connection: what's the same
Both filters use the same -8AN in-line housing and measure 160mm in length. That means installation is identical, and you can swap between micron ratings without changing your plumbing or mounting points.
The stainless steel element and housing are common to both kits, so durability and corrosion resistance are not a differentiator. Your choice is purely about filtration performance.
Decision Rules for -8AN Fuel Filter Micron Size
- Choose 40 micron if: You run EFI injectors and want maximum protection from fine debris. The 40 micron element will catch particles that could damage injector nozzles. Expect to replace or clean the 40 micron filter more often if you run in dusty conditions or with old fuel tanks.
- Choose 100 micron if: You have a very high-flow pump or use the filter as a pre-filter before a finer filter. The 100 micron element offers less flow restriction and a longer service life. Pair the 100 micron filter with a finer post-filter if your injectors need tighter protection.
- If you're still unsure: Match the filter to the fuel pump's recommended micron rating and your injector's tolerance for particles. Many EFI pumps and injectors specify a maximum micron size. When in doubt, choose the 40 micron filter for EFI; it offers more protection and the 1000+ lph flow rating is more than enough for most builds.
Product Facts
- -8AN, 100 micron, 160mm In-line fuel filter kit: This -8AN in-line fuel filter kit uses a stainless steel 100 micron element and housing, measures 160mm, and flows 1000+ lph. The coarser 100 micron element minimizes flow restriction, making it ideal for high-volume pumps or as a pre-filter before a finer filter.
-8AN, 100 micron, 160mm In-line fuel filter kit - -8AN, 40 micron, 160mm In-line fuel filter kit: This -8AN in-line fuel filter kit uses a stainless steel 40 micron element and housing, measures 160mm, and flows 1000+ lph. The finer 40 micron element traps smaller particles, which helps protect EFI injectors from debris that could cause clogging or wear.
-8AN, 40 micron, 160mm In-line fuel filter kit
Which Filter Fits Your Build?
Best for
- EFI street cars and daily drivers needing finer injector protection (40 micron)
- High-horsepower or high-flow pump setups where flow margin is critical (100 micron)
Not for
- Carbureted systems that typically need only 100 micron or coarser filtration
- Applications requiring a different AN size or shorter filter length
