---
title: "Napa 4003 Fuel Filter — $243K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/automotive/napa-4003-fuel-filter"
last_updated: "2026-08-07T04:24:47.017Z"
locale: en
meta:
description: "Niche score 48/100 · $243K/yr market · 300K searches/yr · $51.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 48/100 · $243K/yr market · 300K searches/yr · $51.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Napa 4003 Fuel Filter — $243K/yr Amazon US Niche (2026) - Flapen"
---
# **napa 4003 fuel filter**
**Skip it**
Soft demand (-36.0% this quarter) — this niche doesn't clear our bar today.
Market size 45Growth 7Conversion 20Competition 20Returns 100Price range 95Avg price 93Brand share 14Review moat 100Quality gap 96
**Review moat**
**Incredible****7.25**
avg incumbent reviews — the moat a new listing must climb
**Returns**
**Incredible****0.0%**
return rate — above 5% kills the launch gate
**Quality gap**
**Incredible****3.9★**
avg incumbent rating — lower means beatable quality
**Price range**
**Incredible****$27.97–$71.00**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Avg price**
**Great****$51.52**
avg listing price — sweet spot $15–$100
**Market size**
**Okay****$243K**
$243K/yr · 300K searches
**Conversion**
**Bad****1.6%**
search→purchase rate — share of searches ending in a sale
**Competition**
**Bad****76%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****94%**
top-5 brand share — brand-locked demand
**Growth**
**Bad****-36.0%**
90-day search growth — must beat 0% to launch
**Signals**[** Low Review Barrier**](https://flapen.com/research/niches?market=us&signal=low_review_barrier "Top brand's reviews < 500") [** Quality Gap**](https://flapen.com/research/niches?market=us&signal=quality_gap "Avg rating < 4.0") [** High Price**](https://flapen.com/research/niches?market=us&signal=high_price "Avg price > $50") [** Out of Stock**](https://flapen.com/research/niches?market=us&signal=out_of_stock "OOS rate > 10%")
According to Flapen's Amazon United States niche tracking, napa 4003 fuel filter is a $243K/yr Amazon United States market (300K searches/yr). The top 5 brands hold 94% of demand. Demand peaks in Jan–Feb–Dec. Verdict: Skip it — 48/100.
Data updated Jul 9, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **napa 4003 fuel filter market data**
- **Units sold / yr**
- **2K–3K**
- avg 0–100/product
- **Revenue / yr**
- **$103K–$129K**
- units × avg price
- **Conversion rate**
- **1.6%**
- **Avg BSR**
- **#3,305**
- **Page quality**
- **0%**
- **Prime**
- **0%**
- **Sponsored**
- **100%**
- **Out of stock**
- **14.8%**
- **Avg brand age**
- **54 months**
- **Avg seller age**
- **159 days**
## **Competition & brand share**
The top 5 products capture 76% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**7 **▼falling
**Sellers**
**39**
**Top-5 brand share**
**94%**
Top 20: 100%
**Top-5 click share**
**76%**
Top 20: 100%
**Open market**
**2%**
- linenb31% - Topzywlc29% - TrixmEsque14% - Generic11% - LOKLNEYK9% - Skluauat4% - Open — no brand owns it (1 brand, 2%)
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -36.0% search growth over the last 90 days.
9K7KSpike '24Holiday '24Prime Day '25Spike '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jan, Feb, Dec · busiest ÷ quietest = 2.4×
[**Open Trend **](https://flapen.com/research/us/automotive/napa-4003-fuel-filter/trend)
## **Top napa 4003 fuel filter search terms**
- **solvent filter trap**130K/yr-40.9%0.6% conv. - **solvent trap**76K/yr-37.1%0.6% conv. - **solvent filter trap 1/2 x 28**36K/yr-10.6%1.0% conv. - **fuel filter 1/2 x 28**22K/yr-43.2%0.5% conv. - **solvent filter**6K/yr-27.6%0.7% conv. - **solvent filter trap 1/2 x 28 with baffles**4K/yr+15.0%0.6% conv. - **solvent filter trap 1/2 x 28 suppressor**6K/yr-34.3%0.6% conv. - **1/2x28 fuel filter**6K/yr-41.7%0.5% conv. - **solvent filter trap 5/8 x 24**5K/yr-58.8%0.4% conv. - **solvent tramp 1/2 x 28 with baffles**5K/yr-47.1%1.7% conv. [**All search terms **](https://flapen.com/research/us/automotive/napa-4003-fuel-filter/search-terms)
## **Top napa 4003 fuel filter products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%10%$24K20%$49K30%$73K40%$97K110100 Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 12 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Black Aluminum Solvent Filter Trap Kit High-Efficiency 1/2x28 Fuel Filter with Baffles Suppressor Cleaner Oil Filter**linenb**$31.98**4.8★18 rev](https://www.amazon.com/dp/B0GTGQXL8G) [2**Solvent Filter Trap Black Aluminum Solvent Trap Kit 1/2 x 28 & 5/8 x 24 Automotive Fuel Filter 8 Filter Element with Multiple End Caps for Industrial Grade Automotive Accessories (1/2 x 28)**Topzywlc**$50.66**3.2★14 rev](https://www.amazon.com/dp/B0GVSL3JXG) [3**Solvent Filter Trap 1/2 x 28 Black Aluminum Solvent Filter Trap Kit with Multiple End Caps for Industrial Grade Automotive Accessories (1PC)**Generic**$59.08**5.0★1 rev](https://www.amazon.com/dp/B0GVYLSPJL) [4**Solvent Filter Trap 1/2 X 28 Black Aluminum Fuel Filter Kit with Multiple End Caps Industrial Grade Automotive Accessories 1/2 x 28 * 1 set**TrixmEsque**$63.47**4.4★8 rev](https://www.amazon.com/dp/B0GVMBGHVD) [5**Solvent Filter Trap Black Aluminum Solvent Trap Kit 1/2 x 28 & 5/8 x 24 Automotive Fuel Filter 8 Filter Element with Multiple End Caps for Industrial Grade Automotive Accessories (5/8 x 24)**Topzywlc**$50.67**3.2★14 rev](https://www.amazon.com/dp/B0GVSQM86V)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**6 & 10 Inch Extension Spiral 1/2-28 5/8-24 Single Core Automotive Metal Fuel Filter Housing Assembly Solvent Trap for NAPA 4003 WIX 24003 Car Alloy Fuel Filter Component (6inch 35mm 1/2-28)**GENTERUN**$56.94**1 rev2mo ago](https://www.amazon.com/dp/B0H18Q8QDX) [**Solvent Filter Trap 50mm Universal Aluminum Alloy Solvent Trap Kit 100 Micron Inline Automotive Fuel Filter with An6 An8 An10 Adapter for Filtering Unleaded Gasoline Ethanol and Alcohol (Black)**Topzywlc**$27.97**1 rev3mo ago](https://www.amazon.com/dp/B0GW8D6YTF) [**Solvent Filter Trap 50mm Universal Aluminum Alloy Solvent Trap Kit 100 Micron Inline Automotive Fuel Filter with An6 An8 An10 Adapter for Filtering Unleaded Gasoline Ethanol and Alcohol (Red)**Topzywlc**$27.97**1 rev3mo ago](https://www.amazon.com/dp/B0GW8JPG9S) [**Solvent Filter Trap 1/2 x 28 Black Aluminum Solvent Filter Trap Kit with Multiple End Caps for Industrial Grade Automotive Accessories (1PC)**Generic**$59.08**1 rev3mo ago](https://www.amazon.com/dp/B0GVYLSPJL) [**Solvent Filter Trap Black Aluminum Solvent Trap Kit 1/2 x 28 & 5/8 x 24 Automotive Fuel Filter 8 Filter Element with Multiple End Caps for Industrial Grade Automotive Accessories (1/2 x 28)**Topzywlc**$50.66**14 rev3mo ago](https://www.amazon.com/dp/B0GVSL3JXG)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Solvent Filter Trap 50mm Universal Aluminum Alloy Solvent Trap Kit 100 Micron Inline Automotive Fuel Filter with An6 An8 An10 Adapter for Filtering Unleaded Gasoline Ethanol and Alcohol (Red)**Topzywlc**$27.97**5.0★**▲ 25%**](https://www.amazon.com/dp/B0GW8JPG9S) [**6 & 10 Inch Extension Spiral 1/2-28 5/8-24 Single Core Automotive Metal Fuel Filter Housing Assembly Solvent Trap for NAPA 4003 WIX 24003 Car Alloy Fuel Filter Component (6inch 35mm 1/2-28)**GENTERUN**$56.94**2.0★**▲ 25%**](https://www.amazon.com/dp/B0H18Q8QDX) [**Solvent Filter Trap 5/8 x 24 Black Aluminum Fuel Filter Kit with Multiple End Caps Industrial Grade Automotive Accessories (5/8 x 24 * 1 set)**TrixmEsque**$69.05**4.4★**▲ 25%**](https://www.amazon.com/dp/B0GXK34GST) [**Solvent Filter Trap 50mm Universal Aluminum Alloy Solvent Trap Kit 100 Micron Inline Automotive Fuel Filter with An6 An8 An10 Adapter for Filtering Unleaded Gasoline Ethanol and Alcohol (Black)**Topzywlc**$27.97**5.0★**▲ 25%**](https://www.amazon.com/dp/B0GW8D6YTF) [**Solvent Filter Trap Black Aluminum Solvent Trap Kit 1/2 x 28 & 5/8 x 24 Automotive Fuel Filter 8 Filter Element with Multiple End Caps for Industrial Grade Automotive Accessories (1/2 x 28)**Topzywlc**$50.66**3.2★**▲ 24%**](https://www.amazon.com/dp/B0GVSL3JXG)
**~~View all trending →~~**
## **What buyers say about napa 4003 fuel filter**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Quality-Overall**32%
*“Great product, just as advertised”*
**Advertised Vs Actual Product**14%
*“Works as it should”*
**Ease Of Cleaning**10%
*“Simple twist-on design making the whole process much cleaner and more efficient”*
**Value For Money**8%
*“Maybe a lower price lol would be wonderfully appreciated”*
**Fuel Efficiency**8%
*“After the ATF kicks yours in”*
**Size-Overall**6%
*“Fits perfectly”*
**Motor Power**6%
*“Almost like Hiram Percy Maxim designed it for a 30cc engine himself”*
**Filtration**5%
*“Its a inline filter that works pretty well”*
**Design-Overall**3%
*“Perfect design and works really well, easy to clean, not sure why others rated it poorly,”*
**Assembly/Installation**3%
*“Worked great and easy to install”*
### **What buyers complain about **
**Leak-Proof**25%
*“Leaking junk”*
**Quality-Overall**19%
*“Garbage”*
**Noise Level**19%
*“My neighbors are constantly complaining about the noise these little nitro engines make, so I machined a slip coupler with a 1/2-28 thread and voilà”*
**Material Quality**13%
*“Also the endcaps are cheap plastic”*
**Advertised Vs Actual Product**13%
*“This is not what is advertised DO NOT BUY THIS”*
**Functionality-Overall**6%
*“Does not work at all”*
### **Top return reasons **
**Filtration**33%
**Advertised Vs Actual Product**30%
**Functionality-Overall**10%
**Compatibility-Overall**5%
**Size-Overall**5%
**Defective Material/Parts**5%
**Value For Money**5%
**Quality-Overall**3%
**Material Quality**3%
**Durability**3%
## **Common questions**
- **Is napa 4003 fuel filter profitable to sell on Amazon United States?**
- The niche generates $243K/yr across 12 tracked products. 4 of 12 products launched in the last 360 days are still selling. 90-day search growth is -36.0%. Flapen's verdict: Skip it (48/100).
- **How competitive is the napa 4003 fuel filter niche?**
- 7 brands and 39 sellers compete. The top 5 products take 76% of clicks and top 5 brands hold 94% of demand.
- **What do buyers complain about in napa 4003 fuel filter?**
- Top complaints mined from reviews: Leak-Proof, Quality-Overall, Noise Level. The return rate is 0.0%.
- **When does demand for napa 4003 fuel filter peak?**
- Demand peaks in Jan–Feb–Dec; the busiest month runs 2.4× the quietest.
- **What does it cost to enter the napa 4003 fuel filter niche?**
- Listings span $27.97–$71.00; the average listing price is $51.52 (sweet spot $15–$100). The average incumbent carries 7 reviews — the moat a new listing must climb.
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