---
title: "coolant reservoir cap — Niche Verdict: Worth a look (55/100) | Amazon United States - Flapen"
canonical_url: "https://flapen.com/amazon/research/us/automotive/coolant-reservoir-cap"
last_updated: "2026-07-14T05:31:39.619Z"
locale: en
meta:
  description: "coolant reservoir cap shows no brand lock-in (top 5 brands take 35% of clicks), but a small market ($73K/yr) keeps it on the watch list."
  "og:description": "coolant reservoir cap shows no brand lock-in (top 5 brands take 35% of clicks), but a small market ($73K/yr) keeps it on the watch list."
  "og:title": "coolant reservoir cap — Niche Verdict: Worth a look (55/100) | Amazon United States - Flapen"
---

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# **coolant reservoir cap**

**Worth a look**

Shows no brand lock-in (top 5 brands take 35% of clicks), but a small market ($73K/yr) keeps it on the watch list.

Market size 18Growth 20Conversion 61Competition 93Returns 55Price range 31Avg price 24Brand share 96Review moat 87Quality gap 76

**Brand share**

**Incredible****35%**

top-5 brand share — no brand owns this niche

**Competition**

**Great****22%**

top-5 click share — an open shelf

**Review moat**

**Great****264.25**

avg incumbent reviews — the moat a new listing must climb

**Quality gap**

**Great****4.3★**

avg incumbent rating — lower means beatable quality

**Conversion**

**Good****5.3%**

search→purchase rate — share of searches ending in a sale

**Returns**

**Good****2.8%**

return rate — above 6% kills the launch gate

**Price range**

**Okay****$3.08–$20.38**

cheapest to priciest tracked listing — scored on the share inside $15–$100

**Avg price**

**Bad****$8.59**

avg listing price — sweet spot $15–$100

**Growth**

**Bad****-10.1%**

90-day search growth — must beat 0% to launch

**Market size**

**Bad****$73K**

$73K/yr · 162K searches

## **Competition**

Clicks spread well past the top 5 (22% combined) — an open shelf where new products get seen.

**Brands**

**61 **▲rising

**Sellers**

**148**

**Top-5 brand share**

**35%**

**Open market**

**61%**

- Dorman13% - ACDelco7% - ROVIKE5% - KEVWR5% - SWQS4% - DeFageH4%

## **Product shelf**

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

0%2%$1K4%$3K6%$4K8%$6K1101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)1 product missing review or click data not plotted

All 89 tracked products in this niche — three views at once, no toggling.

### **Top sellers**

by 90-day click share

[1![Dorman 54201 Engine Coolant Reservoir Cap Compatible with Select Models](https://m.media-amazon.com/images/I/41lzLRp1tvL.jpg)**Dorman 54201 Engine Coolant Reservoir Cap Compatible with Select Models**Dorman**$12.42**4.6★4,822 rev](https://www.amazon.com/dp/B00Z7MMSIS) [2![2PCS Engine Radiator Coolant Water Tank Black Reservoir Cap Compatible with Infiniti Nissan Renault OEM# 21712-79900](https://m.media-amazon.com/images/I/51ZjS0ddk2L.jpg)**2PCS Engine Radiator Coolant Water Tank Black Reservoir Cap Compatible with Infiniti Nissan Renault OEM# 21712-79900**KEVWR**$6.26**4.4★385 rev](https://www.amazon.com/dp/B0CH2WHK8Q) [3![DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35](https://m.media-amazon.com/images/I/41zhRQhK12L.jpg)**DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35**DeFageH**$4.37**4.6★26 rev](https://www.amazon.com/dp/B0GHXR6BNP) [4![13502353 Coolant Reservoir Cap for Chevy GMC Buick Cadillac -Silverado 1500 2500 3500 Express Avalanche Suburban Captiva Cavalier Equinox Malibu Savana Sierra Yukon Radiator Surge Tank Cap](https://m.media-amazon.com/images/I/51NDXSymSoL.jpg)**13502353 Coolant Reservoir Cap for Chevy GMC Buick Cadillac -Silverado 1500 2500 3500 Express Avalanche Suburban Captiva Cavalier Equinox Malibu Savana Sierra Yukon Radiator Surge Tank Cap**ROVIKE**$11.52**4.4★162 rev](https://www.amazon.com/dp/B09XWDBMN9) [5![Car Radiator Cap Replacement OEM#68442532aa 53479332 Coolant Reservoir Cap Compatible with Chrysler Dodge Jeep Ram Standard Car Accessories Radiator Cover Easy to Mounting](https://m.media-amazon.com/images/I/41fv3r3SzML.jpg)**Car Radiator Cap Replacement OEM#68442532aa 53479332 Coolant Reservoir Cap Compatible with Chrysler Dodge Jeep Ram Standard Car Accessories Radiator Cover Easy to Mounting**Stacool**$7.20**4.5★84 rev](https://www.amazon.com/dp/B0D14C7WT3)

**~~View all top sellers →~~**

### **Newest**

by launch date

[![CCNU Coolant Reservoir Cap Replacement for Honda Odyssey 2011-2017 Acura ILX Radiator Overflow Expansion Tank Cap Replace 19102-RV0-A00 19102RV0A00 Engine Coolant Reservoir Tank Lid](https://m.media-amazon.com/images/I/31tteRZyknL.jpg)**CCNU Coolant Reservoir Cap Replacement for Honda Odyssey 2011-2017 Acura ILX Radiator Overflow Expansion Tank Cap Replace 19102-RV0-A00 19102RV0A00 Engine Coolant Reservoir Tank Lid**CCNU**$5.94**0 rev3mo ago](https://www.amazon.com/dp/B0GTLRGGZL) [![4PCS Coolant Reservoir Cap Replacement OEM# 21712-79900 - Radiator Overflow Coolant Reservoir Tank Cap Compatible with Nissan Murano Rogue Versa Quest & Infiniti EX35 FX37 G35 M35](https://m.media-amazon.com/images/I/51N4GLOhowL.jpg)**4PCS Coolant Reservoir Cap Replacement OEM# 21712-79900 - Radiator Overflow Coolant Reservoir Tank Cap Compatible with Nissan Murano Rogue Versa Quest & Infiniti EX35 FX37 G35 M35**Alfaly**$3.08**11 rev4mo ago](https://www.amazon.com/dp/B0GQV5L763) [![DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35](https://m.media-amazon.com/images/I/41zhRQhK12L.jpg)**DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35**DeFageH**$4.37**26 rev5mo ago](https://www.amazon.com/dp/B0GHXR6BNP) [![Houlishu 2 Pack Coolant Reservoir Cap Replacement Universal Radiator Reservoir Cap Compatible with OEM# 21712-79900 Black Overflow Tank Cover for Water & Antifreeze](https://m.media-amazon.com/images/I/41VmGxWsGBL.jpg)**Houlishu 2 Pack Coolant Reservoir Cap Replacement Universal Radiator Reservoir Cap Compatible with OEM# 21712-79900 Black Overflow Tank Cover for Water & Antifreeze**houlishu**$6.09**18 rev5mo ago](https://www.amazon.com/dp/B0GGYJHFBD) [![Icyfond Engine Radiator Coolant Water Tank Reservoir Cap OEM 21712-79900 Engine Cooling System Overflow Expansion Bottle Cap Compatible with Nissan Murano Rogue Versa Infiniti](https://m.media-amazon.com/images/I/41k4CF5aFvL.jpg)**Icyfond Engine Radiator Coolant Water Tank Reservoir Cap OEM 21712-79900 Engine Cooling System Overflow Expansion Bottle Cap Compatible with Nissan Murano Rogue Versa Infiniti**Icyfond**$7.79**4 rev6mo ago](https://www.amazon.com/dp/B0G796KTLB)

**~~View all new products →~~**

### **Trending**

90-day click momentum

[![CCNU Coolant Reservoir Cap Replacement for Honda Odyssey 2011-2017 Acura ILX Radiator Overflow Expansion Tank Cap Replace 19102-RV0-A00 19102RV0A00 Engine Coolant Reservoir Tank Lid](https://m.media-amazon.com/images/I/31tteRZyknL.jpg)**CCNU Coolant Reservoir Cap Replacement for Honda Odyssey 2011-2017 Acura ILX Radiator Overflow Expansion Tank Cap Replace 19102-RV0-A00 19102RV0A00 Engine Coolant Reservoir Tank Lid**CCNU**$5.94**0.0★**▲ 314%**](https://www.amazon.com/dp/B0GTLRGGZL) [![4PCS Coolant Reservoir Cap Replacement OEM# 21712-79900 - Radiator Overflow Coolant Reservoir Tank Cap Compatible with Nissan Murano Rogue Versa Quest & Infiniti EX35 FX37 G35 M35](https://m.media-amazon.com/images/I/51N4GLOhowL.jpg)**4PCS Coolant Reservoir Cap Replacement OEM# 21712-79900 - Radiator Overflow Coolant Reservoir Tank Cap Compatible with Nissan Murano Rogue Versa Quest & Infiniti EX35 FX37 G35 M35**Alfaly**$3.08**4.8★**▲ 302%**](https://www.amazon.com/dp/B0GQV5L763) [![Houlishu 2 Pack Coolant Reservoir Cap Replacement Universal Radiator Reservoir Cap Compatible with OEM# 21712-79900 Black Overflow Tank Cover for Water & Antifreeze](https://m.media-amazon.com/images/I/41VmGxWsGBL.jpg)**Houlishu 2 Pack Coolant Reservoir Cap Replacement Universal Radiator Reservoir Cap Compatible with OEM# 21712-79900 Black Overflow Tank Cover for Water & Antifreeze**houlishu**$6.09**3.4★**▲ 259%**](https://www.amazon.com/dp/B0GGYJHFBD) [![DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35](https://m.media-amazon.com/images/I/41zhRQhK12L.jpg)**DeFageH 2Pcs Coolant Reservoir Cap - Premium Leak-Proof Coolant Caps for OEM# 21712-79900 Compatible with Nissan Pathfinder Maxima Murano Infiniti G35**DeFageH**$4.37**4.6★**▲ 216%**](https://www.amazon.com/dp/B0GHXR6BNP) [![SWQS Coolant Reservoir Tank Cap for Toyota Engine Coolant Expansion Tank Cap 16471-0A030 Radiator Coolant Caps Replacement for Toyota Sienna 2004-2010 Lexus RX330 2004-2006 & RX350 2007-2009 (Black)](https://m.media-amazon.com/images/I/41XUblMdkAL.jpg)**SWQS Coolant Reservoir Tank Cap for Toyota Engine Coolant Expansion Tank Cap 16471-0A030 Radiator Coolant Caps Replacement for Toyota Sienna 2004-2010 Lexus RX330 2004-2006 & RX350 2007-2009 (Black)**SWQS**$9.93**3.0★**▲ 184%**](https://www.amazon.com/dp/B0G4TXK4LH)

**~~View all trending →~~**

## **Demand & seasonality**

Weekly Amazon search volume, last 104 weeks — -10.1% search growth over the last 90 days.

4K3KHoliday '24 seasonSepDecMarJunAugNovMarMay

No pronounced peak months · busiest ÷ quietest = 1.1×

## **Reviews**

What buyers praise and complain about, mined from review topics.

### **What buyers love **

**Size-Overall**55%

*“Fit great”*

**Quality-Overall**13%

*“Quality replacement”*

**Value For Money**7%

*“Good price”*

**Advertised Vs Actual Product**5%

*“Worked as advertised”*

**Coolant**4%

*“Worked great as direct replacement for coolant reserve tank fill cap”*

**Efficiency**4%

*“Does the job just fine”*

**Leak-Proof**2%

*“No leaks so far”*

**Assembly/Installation**1%

*“Easy installation”*

**Durability**1%

*“durable”*

**Ease Of Use**1%

*“Easy to use”*

### **What buyers complain about **

**Size-Overall**23%

*“Doesnt fit advertised to fit”*

**Compatibility-Overall**14%

*“Did not fit Suzuki Kizashi”*

**Quality-Overall**11%

*“Expected much higher quality from Gates”*

**Durability**8%

*“Not durable”*

**Coolant**7%

*“Stop coolant loss”*

**Functionality-Overall**5%

*“doesnt fix”*

**Leak-Proof**4%

*“Will leak everywhere”*

**Advertised Vs Actual Product**3%

*“Do not believe what is advertised”*

**Value For Money**3%

*“absolute waste of money”*

**Pressure**3%

*“It doesnt hold pressure”*

### **Top return reasons **

**Size-Overall**53%

**Coolant**22%

**Compatibility-Overall**10%

**Advertised Vs Actual Product**3%

**Defective Material/Parts**3%

**Pressure**2%

**Value For Money**2%

**Functionality-Overall**1%

**Leak-Proof**1%

**Product Condition**1%