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41

tune up kit spark plugs and wires

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A small market ($58K/yr) — this niche doesn't clear our bar today.

Market size 15Growth 22Conversion 40Competition 50Returns 53Price range 62Avg price 95Brand share 36Review moat 71Quality gap 42

Avg price

Incredible$45.09

avg listing price — sweet spot $15–$100

Review moat

Good665.71

avg incumbent reviews — the moat a new listing must climb

Price range

Good$6.60–$144.09

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

Returns

Good2.9%

return rate — above 6% kills the launch gate

Competition

Good55%

top-5 click share — leaders hold, buyers still browse

Quality gap

Okay4.5★

avg incumbent rating — lower means beatable quality

Conversion

Okay3.2%

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

Brand share

Okay84%

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

Growth

Bad-7.0%

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

Market size

Bad$58K

$58K/yr · 41K searches

Competition

The top 5 products take 55% of clicks — established leaders, but buyers still shop beyond them.

Brands

15 flat

Sellers

75

Top-5 brand share

84%

Open market

13%

  • ACDelco32%
  • NGK29%
  • Ozikutech11%
  • TICANEE6%
  • AD Auto Parts4%
  • MCCKLE3%
  • Open — no brand owns it (9 brands, 13%)

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%5%$3K10%$6K15%$9K20%$12K1101001K10K Reviews — right = deep review moat Market share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 28 tracked products in this niche — three views at once, no toggling.

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — -7.0% search growth over the last 90 days.
1K750Spike '24Spike '25Spike '26SepDecMarJunAugNovMarMay

No pronounced peak months · busiest ÷ quietest = 1.4×

Reviews

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

What buyers love

Value For Money22%

“Great value”

Quality-Overall18%

“Good product as expected”

Size-Overall17%

“Fit perfect”

Socket/Port/Plug12%

“Good plugs”

Assembly/Installation8%

“Easy installation”

Advertised Vs Actual Product7%

“Product was exactly as described”

Efficiency6%

“Performing great in my vehicle”

Durability2%

“Durable”

Functionality-Overall2%

“now it runs as good as can be expected”

Correct Contents1%

“Correct parts”

What buyers complain about

Quality-Overall19%

“Cheap quality”

Socket/Port/Plug12%

“The spark plugs dont fit”

Size-Overall11%

“Too short”

Compatibility-Overall9%

“Not compatible”

Flammable9%

“Causes random misfires”

Functionality-Overall6%

“Didnt work”

Product Condition6%

“I ordered this spark plugs and looked dirty and used”

Durability5%

“2 out of 8 broke in half literally requiring easy out to extract”

Defective Material/Parts4%

“Terrible sends broken parts”

Value For Money4%

“These are very much more expensive at parts store”

Top return reasons

Size-Overall33%
Compatibility-Overall17%
Advertised Vs Actual Product11%
Socket/Port/Plug8%
Product Condition7%
Defective Material/Parts6%
Value For Money4%
Functionality-Overall3%
Flammable2%
Quality-Overall2%