Is radiator flush profitable to sell on Amazon United States?

The niche generates $287K/yr across 16 tracked products. 1 of 3 products launched in the last 360 days are still selling. 90-day search growth is -9.8%. Flapen's verdict: Worth a look (50/100).

How competitive is the radiator flush niche?

12 brands and 73 sellers compete. The top 5 products take 70% of clicks and top 5 brands hold 83% of demand.

What do buyers complain about in radiator flush?

Top complaints mined from reviews: Leak-Proof, Compatibility-Overall, Quality-Overall. The return rate is 1.9%.

When does demand for radiator flush peak?

Demand is steady year-round — the busiest month runs 1.3× the quietest.

What does it cost to enter the radiator flush niche?

Listings span $5.82–$92.76; the average listing price is $21.11 (sweet spot $15–$100). The average incumbent carries 545 reviews — the moat a new listing must climb.

radiator flush

Worth a look

Shows a sweet-spot price point ($21.11 avg), but soft demand (-9.8% this quarter) keeps it on the watch list.

Avg price

Great$21.11

avg listing price — sweet spot $15–$100

Price range

Great$5.82–$92.76

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

Conversion

Great7.7%

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

Returns

Great1.9%

return rate — above 5% kills the launch gate

Review moat

Good545.13

avg incumbent reviews — the moat a new listing must climb

Market size

Good$287K

$287K/yr · 177K searches

Quality gap

Okay4.5★

avg incumbent rating — lower means beatable quality

Brand share

Okay83%

top-5 brand share — brands hold most of the demand

Competition

Bad70%

top-5 click share — a locked-up shelf

Growth

Bad-9.8%

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

According to Flapen's Amazon United States niche tracking, radiator flush is a $287K/yr Amazon United States market (177K searches/yr). The top 5 brands hold 83% of demand. Verdict: Worth a look — 50/100.

Data updated Jul 9, 2026 · scored weekly · How we score niches

radiator flush market data

Units sold / yr: 10K–13K; avg 500–750/product
Revenue / yr: $211K–$264K; units × avg price
Conversion rate: 7.7%
Avg BSR: #69
Page quality: 0%
Prime: 100%
Sponsored: 69%
Out of stock: 2.7%
Avg brand age: 78 months
Avg seller age: 162 days

Competition & brand share

The top 5 products capture 70% of clicks — a locked-up shelf that new listings rarely crack.

Brands

12 rising

Sellers

Top-5 brand share

83%

Top 20: 100%

Top-5 click share

70%

Top 20: 100%

Open market

12%

Prestone36%
BlueDevil Products19%
CRC19%
Gunk5%
Design Engineering5%
IRONTITE5%
Open — no brand owns it (6 brands, 12%)

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — -9.8% search growth over the last 90 days.

No pronounced peak months · busiest ÷ quietest = 1.3×

Open Trend

Top radiator flush search terms

radiator flush83K/yr -5.1%7.2% conv.
coolant flush41K/yr -12.1%4.8% conv.
radiator flush and cleaner16K/yr -16.1%6.6% conv.
cooling system flush6K/yr -11.4%5.8% conv.
thermocure5K/yr -1.5%17.3% conv.
cooling system cleaner4K/yr -10.8%4.9% conv.
coolant cleaner4K/yr -2.0%5.3% conv.
coolant flush cleaner5K/yr -31.9%6.5% conv.
coolant system flush4K/yr -19.9%7.0% conv.
thermocure radiator flush4K/yr -33.0%17.8% conv.

All search terms

Top radiator flush 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.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 16 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

Prestone AS105 Total Cooling System Cleaner for Radiator Heater Core and Hoses 22 oz. 1 pack

Prestone$13.854.6★2,360 rev

CRC Thermocure Coolant System Rust Remover 32 Oz Rust Remover for Vehicle Cooling Systems Removes Rust Scale and Deposits

CRC$26.144.6★1,572 rev

Prestone Products Corp Radiator Flush/Cleaner AS105R

Prestone$5.824.7★181 rev

BlueDevil 3 in 1 Radiator Flush | Automotive Oil Degreaser Radiator Flush Rust Remover | 32 oz. | Multi-Vehicle Formula

BlueDevil Products$12.824.5★587 rev

DEI Radiator Relief Cooling System Flush Improves Cooling Performance 16 oz

Design Engineering$11.784.2★42 rev

Newest

by launch date

LURKA Coolant System Flush Gun Lever Action Heater Core Flush Kit with 3/4 & 1/2 Garden Hose Adapters/Shut-Off Valve Air & Water Combo Radiator Flusher Nozzles for 5 Sizes of Hoses (19-40mm)

LURKA$27.036 rev

5mo ago

QUFYSK Coolant Flush Gun Lever Action Heater Core Flush Kit Coolant Flush Kit for Automotive Coolant Flush Air and Water Radiator Flush Kit with Nozzles for 19-40mm Hoses

QUFYSK$29.8127 rev

6mo ago

ERRECOM Zeus+ Cleaner for Radiators and Cooling Systems 12 fl oz Bottle (350 mL)

ERRECOM$11.93151 rev

7mo ago

BlueDevil Radiator Flush 32 oz | Deep Cleaning Coolant System Flush | Removes Rust Scale & Grime

BlueDevil Products$92.76587 rev

1y ago

BILITOOLS Coolant Funnel Kit Automotive Radiator Coolant Filling Tool

BILITOOLS$18.3258 rev

1y ago

What buyers say about radiator flush

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

What buyers love

Quality-Overall18%

“Solid quality”

Efficiency14%

“Working good”

Value For Money11%

“Good price”

Ease Of Use9%

“Easy to use”

Advertised Vs Actual Product9%

“Works as it should”

Coolant6%

“No spills, easy adding, no more bubble over from burping your coolant system”

Ease Of Cleaning5%

“Cleans as it should”

Leak-Proof3%

“Doesn't leak”

Durability2%

“But it really seemed to break things up nicely”

Heating2%

“This coolant flush gun made back flushing my heater core a piece of cake”

What buyers complain about

Leak-Proof18%

“not sure how much leaked out”

Compatibility-Overall11%

“Adapters would not fit my Toyota or Honda”

Quality-Overall9%

“Absolutely trash in every”

Rusts/Corrodes9%

“it quickly became contaminated with rust also”

Heating6%

“Engine would overheat after running about 5 miles”

Coolant3%

“Its the only way I was able to get all air out of my cooling system on my 7th generation honda civic”

Instructions/User Manual/Troubleshooting2%

“It doesn't come with a manual”

Water Resistance2%

“The water was really nasty”

Pressure1%

“The only downside to that was no air pressure”

Color1%

“deep red that is difficult to see when it is fully dissolved”

Top return reasons

Coolant20%

Size-Overall16%

Compatibility-Overall15%

Advertised Vs Actual Product12%

Leak-Proof7%

Defective Material/Parts5%

Value For Money5%

Functionality-Overall4%

Rusts/Corrodes3%