spark plug gap tool
Worth a lookShows searches that convert (13.4% search→purchase), but prices mostly outside the sweet spot ($3.89–$17.61) keeps it on the watch list.
Conversion
Incredible13.4%search→purchase rate — share of searches ending in a sale
Returns
Incredible0.9%return rate — above 5% kills the launch gate
Market size
Good$736K$736K/yr · 556K searches
Review moat
Good1,235avg incumbent reviews — the moat a new listing must climb
Brand share
Good73%top-5 brand share — brands hold most of the demand
Growth
Okay+12.2%90-day search growth — must beat 0% to launch
Competition
Okay65%top-5 click share — leaders hold, buyers still browse
Avg price
Okay$9.90avg listing price — sweet spot $15–$100
Quality gap
Okay4.6★avg incumbent rating — lower means beatable quality
Price range
Bad$3.89–$17.61cheapest to priciest tracked listing — scored on the share inside $15–$100
According to Flapen's Amazon United States niche tracking, spark plug gap tool is a $736K/yr Amazon United States market (556K searches/yr). The top 5 brands hold 73% of demand. Demand peaks in Apr. Verdict: Worth a look — 54/100.
Data updated Jul 12, 2026 · scored weekly · How we score niches
spark plug gap tool market data
- Units sold / yr
- 60K–80K
- avg 4,000–5,000/product
- Revenue / yr
- $594K–$792K
- units × avg price
- Conversion rate
- 13.4%
- Avg BSR
- #38
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 56%
- Out of stock
- 0.0%
- Avg brand age
- 44 months
- Avg seller age
- 161 days
Competition & brand share
The top 5 products take 65% of clicks — established leaders, but buyers still shop beyond them.Brands
14 falling
Sellers
77
Top-5 brand share
73%
Top 20: 100%
Top-5 click share
65%
Top 20: 100%
Open market
20%
- CTA Tools38%
- Toolwiz12%
- GEAROLL9%
- PQY7%
- Kastar7%
- NYTKL6%
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — +12.2% search growth over the last 90 days.Peak months: Apr · busiest ÷ quietest = 1.6×
Top spark plug gap tool search terms
- spark plug gap tool361K/yr
- spark plug gapping tool53K/yr
- spark plug gapper24K/yr
- sparkplug gap tool14K/yr
- spark plug gap gauge13K/yr
- calibrador de bujias automotriz12K/yr
- spark plug gap12K/yr
- spark plug feeler gauge9K/yr
- spark plug gap tool iridium plugs5K/yr
- spark plug gapper tool8K/yr
Top spark plug gap tool 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.
All 16 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
CTA Tools 3235 Spark Plug Gapper: Coin-Style Spark Plug Gap Tool 0.0200.100 Measurement Range Plated Steel Quick-Check Reference Tool
CTA Tools$4.804.6★7,456 rev
Toolwiz Spark Plug Gap Tool with 32 Blade Steel Feeler Gauge Gapping Tool for Most 10mm 12mm 14mm 16mm Thread Spark Plugs Red
Toolwiz$17.614.6★607 rev
GEAROLL Spark Plug Gap Tool with 32 Blade Steel Feeler Gauge Spark Plug Gapping Tool for Most 10mm 12mm 14mm 16mm Thread Spark Plugs Red
GEAROLL$16.604.7★187 rev
CTA Tools 3238 9 Wire Spark Plug Gap Gauge
CTA Tools$6.074.5★1,970 rev
PQY Universal Spark Plug Gap Tool with 32 Blades Steel Feeler Gauge Spark Plug Gapper Gapping Tool Adjuster for Most 10mm 12mm 14mm 16mm Sparkplug Red
PQY$17.114.5★740 rev
Newest
by launch dateGEAROLL Spark Plug Gap Tool with 32 Blade Steel Feeler Gauge Spark Plug Gapping Tool for Most 10mm 12mm 14mm 16mm Thread Spark Plugs Red
GEAROLL$16.60187 rev
2pcs Feeler Gauges Set Stainless Steel 32 Straight & 16 Angled Blades Dual Marked SAE/Metric Wider Range Spark Plug Gap Tool Filler Gauges Kit for Valves Automotive Piston Guitar
Hoiny$7.15530 rev
CNRAQR Universal Spark Plug Gap Tool for Most 10mm 12mm 14mm 16mm Spark Plugs with 1 Set Feeler Gauge Blue
CNRAQR$14.55131 rev
NYTKL Spark Plug Measuring Tool Wire Spark Plug Gap Gauge Scaled from 0.020 to 0.100 Inch Universal Zinc Alloy Spark Plug Adjustment Tools Gapper Gauge Car Accessories (1PCS)
NYTKL$4.0191 rev
Guslcez Stainless Steel Feeler Gauge 32-Blade 0.04-0.88 mm (0.0015-0.035 Inch) Precision Gap Measuring Tool for Valve Adjustment Spark Plug Gap Dual Marked Metric and Imperial Measuring Tools
Guslcez$5.01147 rev
Trending
90-day click momentum
carleef 1PC Car Spark Plug Measuring Tool Standard 0.020 to 0.100 Inch Cars Spark Plug Gap Tool for Quick Reading Scale Essential Car Accessories Sparks Plugs Gapping Tools
carleef$3.894.5★
NYTKL Spark Plug Measuring Tool Wire Spark Plug Gap Gauge Scaled from 0.020 to 0.100 Inch Universal Zinc Alloy Spark Plug Adjustment Tools Gapper Gauge Car Accessories (1PCS)
NYTKL$4.014.3★
2pcs Feeler Gauges Set Stainless Steel 32 Straight & 16 Angled Blades Dual Marked SAE/Metric Wider Range Spark Plug Gap Tool Filler Gauges Kit for Valves Automotive Piston Guitar
Hoiny$7.154.7★
GEAROLL Spark Plug Gap Tool with 32 Blade Steel Feeler Gauge Spark Plug Gapping Tool for Most 10mm 12mm 14mm 16mm Thread Spark Plugs Red
GEAROLL$16.604.7★
Toolwiz Spark Plug Gap Tool 2pcs High Precise Gapping Tool Adjustment Kit for 12mm 14mm Thread Spark Plug
Toolwiz$7.724.5★
What buyers say about spark plug gap tool
What buyers praise and complain about, mined from review topics.What buyers love
“Excellent Product”
“Works as it should”
“Worth the money”
“Easy to use”
“Works great”
“Good spark plug gap tool”
“Lots of sizes”
“durable”
“Well built”
“is a highly accurate gage-I measured with a digital calipher”
What buyers complain about
“Low quality”
“Totally inaccurate”
“Not even close to the correct sizes it should be”
“Wont hold short plugs”
“Well dot does not work with small plugs”
“can only close then which is the easy part”
“The feeler gauges it comes with dont have anything thick enough for my cars spec”
“it came apart”
“I received a used set”
“One of the gauge wire fell out”
Top return reasons
Common questions
- Is spark plug gap tool profitable to sell on Amazon United States?
- The niche generates $736K/yr across 16 tracked products. 2 of 2 products launched in the last 360 days are still selling. 90-day search growth is +12.2%. Flapen's verdict: Worth a look (54/100).
- How competitive is the spark plug gap tool niche?
- 14 brands and 77 sellers compete. The top 5 products take 65% of clicks and top 5 brands hold 73% of demand.
- What do buyers complain about in spark plug gap tool?
- Top complaints mined from reviews: Quality-Overall, Measurement/Reading Accuracy, Size-Overall. The return rate is 0.9%.
- When does demand for spark plug gap tool peak?
- Demand peaks in Apr; the busiest month runs 1.6× the quietest.
- What does it cost to enter the spark plug gap tool niche?
- Listings span $3.89–$17.61; the average listing price is $9.90 (sweet spot $15–$100). The average incumbent carries 1,235 reviews — the moat a new listing must climb.