Spark Plug Tester Market Report: Sales Volume, Market Share, Leading Brands & Market Trends
Spark Plug Tester sales on Amazon US totaled 24,150 units in July 2026 (▲ 1.3% vs. the prior month), generating an estimated $281,701 in revenue across the 50 top-ranked ASINs for this search term. Demand is heavily concentrated at the top of the ranking — the ten best performers capture 80.3% of unit volume and 71.9% of revenue, while a typical listing is priced at $18.21. The keyword itself pulled 21,236 Amazon queries over the same period (▲ 8.6% MoM).
Zooming out to the 12-month window ending July 2026, the spark plug tester Top 50 moved 233,250 units and $2,604,861 in cumulative sales — an average of 19,438 units and $217,072 per month. Monthly throughput topped out at 25,500 units in April 2026 and dipped to 13,050 in May 2026, leaving the latest reading 16.9% higher than August 2025.
Spark Plug Tester Sales Trend (Trailing 12 Months)
Based on the top 50 ASINs by monthly sales for this keyword
2025/08
2025/09
2025/10
2025/11
2025/12
2026/01
2026/02
2026/03
2026/04
2026/05
2026/06
2026/07
Monthly Sales 2026/07
24.1K
▲ 1.3% MoM
Monthly Revenue 2026/07
$281.7K
▲ 0.3% MoM
Top 10 Market Share 2026/07
80.3%
Spark Plug Tester Market Share & Sales Concentration on Amazon US — July 2026
The most-sold spark plug tester listing on Amazon US in July 2026 is ASIN B0D8PXNPYH (Brand: WINAMOO), which sold 6,000 units at $8.95 apiece — equal to 24.8% of every unit tracked in this report and 1.5× the volume of the No. 2 listing.
The Top 10 ASINs account for 19,400 units and $202,406 in July 2026 — 80.3% of unit volume and 71.9% of revenue among all 50 ranked ASINs in this report.
Sales Volume of Top ASINs for 'Spark Plug Tester' on Amazon
July 2026
Is 80.3% Top 10 share highly concentrated?
Ask AI to evaluate competition, market structure, and entry opportunities using ’s tracked Amazon sales, ranking, and keyword data.
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Top 5 Volume Share breakdown
B0D8PXNPYH
WINAMOO Automotive Test Light with 3-48V LED Digital Voltage Display, Auto Circuit Tester with Voltmeter & Dual Color Polarity Indicate, Electric Test Pen w/Stainless Probe for Car/Truck/SUV Checker
6K
▲ 20.0%vs. prior month
$53.7K
latest month
12-month trend
B0FJR8M3ZV
Hoiny 2pcs Feeler Gauges Set Stainless Steel, Spark Plug Gap Tool | 32 Straight & 16 Angled Blades, Dual Marked SAE/Metric Wider Range, Filler Gauges Kit for Valves, Automotive, Piston, Guitar
4K
▲ 0.0%vs. prior month
$31K
latest month
12-month trend
B00144AZ6K
CTA Tools 3235 Spark Plug Gapper: Coin-Style Spark Plug Gap Tool, 0.020"–0.100" Measurement Range, Plated Steel, Quick-Check Reference Tool
3K
▲ 0.0%vs. prior month
$15K
latest month
12-month trend
B09FJSZD2H
SINGARO Inline Spark Plug Tester, Plug-in Engine Ignition Tester, Car Exterior Accessories, Automobile, Lawn Mower,Engine Verification-Armature Diagnostic Test Tool
1K
▼ 50.0%vs. prior month
$7K
latest month
12-month trend
B0C1RP7SSS
YEYETUO 2PCS Spark Plug Tester, Ignition Coil Tester for Engines for Cars | Inline Spark Tester, Quickly Diagnose Ignition and Engine Defects, for Cars, Lawnmowers, Internal / External Engines
1K
▲ 0.0%vs. prior month
$7K
latest month
12-month trend
B0CNH5P66F
Universal Fuel Injector Tester and Cleaner Tool Kit, DIY Cleaning Tool Kit, 8 Pulse Modes, 4 Wire Dual Channel for 2 Fuel Injectors, 8 Size Cleaning Adapters, 12V/5V Output Power
1K
▲ 0.0%vs. prior month
$26.6K
latest month
12-month trend
Unlock to view all Top 50 ASIN competitors and their sales contributions
Best Spark Plug Tester Brands on Amazon US — Top 3 Brand Sales Concentration (July 2026)
WINAMOO is the best-performing spark plug tester brand in July 2026, moving 6,000 units across 1 ASIN for 30.9% of Top 10 volume. Hoiny follows with 4,000 units (20.6%), ahead of CTA Tools on 3,000 units (15.5%).
With 9 brands splitting the Top 10 and 67.0% of volume sitting with three of them, this is a concentrated shelf — the leaders hold multiple listings or one very high-velocity ASIN, so a new entrant competes against established review moats rather than an open field. Average selling prices among the leaders run from $5.02 to $8.95, which frames the price band a competing listing has to justify.
Brand share of Top 10 volume
WINAMOO
1 ASIN in Top 10
30.9%
Units
6K
Revenue
$53.7K
Avg. price
$8.95
B0D8PXNPYH
$8.95·★4.7·3K revsWINAMOO Automotive Test Light with 3-48V LED Digital Voltage Display, Auto Circuit Tester with Voltmeter & Dual Color Polarity Indicate, Electric Test Pen w/Stainless Probe for Car/Truck/SUV Checker
Units sold6K
Hoiny
1 ASIN in Top 10
20.6%
Units
4K
Revenue
$31K
Avg. price
$6.99
B0FJR8M3ZV
$6.99·★4.7·664 revsHoiny 2pcs Feeler Gauges Set Stainless Steel, Spark Plug Gap Tool | 32 Straight & 16 Angled Blades, Dual Marked SAE/Metric Wider Range, Filler Gauges Kit for Valves, Automotive, Piston, Guitar
Units sold4K
CTA Tools
1 ASIN in Top 10
15.5%
Units
3K
Revenue
$15K
Avg. price
$5.02
B00144AZ6K
$5.02·★4.6·7.5K revsCTA Tools 3235 Spark Plug Gapper: Coin-Style Spark Plug Gap Tool, 0.020"–0.100" Measurement Range, Plated Steel, Quick-Check Reference Tool
Units sold3K
Trending Spark Plug Tester Products — Growth Leaders & New Top 10 Entrants
Based on July 2026 data, this shortlist surfaces the two kinds of ASIN worth keeping an eye on — the ones that just broke into the Top 10, and the ones growing fastest month over month. On the growth side, B01HU2L1NU leads positive momentum with ▲ 250.0% MoM growth on 700 units, with B098QNW4R3 close behind at ▲ 100.0% MoM on 400 units.
The two signals carry different weight. A fresh entrant means share has already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date. A steep growth rate works as the earlier warning: it marks demand that is still compounding, usually a month or two before the ranking catches up to it.
B01HU2L1NU
Ram-Pro Inline Spark Tester, Plug Engine Ignition 6-12 Volt Fool-Proof – Pick Up Coil/Armature Diagnostic Detector Tool for Automotive, Car, Lawnmower, Small & Big Internal/External Engines
Price
$8.99
Rating
4.5
Reviews
6.8K
Latest month sales
B098QNW4R3
9 Pcs Automotive Compression Tester Kit and Spark Plug Tester, Red | 0-300PSI Universal Car Motorcycle Chainsaw Outboard Motor Snowmobile Engine Testing Tools for Cylinder Pressure Gauge
Price
$21.49
Rating
4.5
Reviews
1.7K
Latest month sales
B0DMZ7GNZH
DXNQ Spark Plug Measuring Tool, Zinc Alloy Measuring Wire Spark Plug Gap Gauge Tool Scaled from 0.020" to 0.100", Portable Spark Plug Adjustment Tool, Gap Measuring Tool Car Accessories
Unlock to view ASIN details and product titles
Price
$3.69
Rating
4.5
Reviews
130
Latest month sales
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