NGK LKR7DIX-11S Iridium IX Spark Plug (93175 Iridium Ix), 4 Pack
NGK
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Best NGK iridium
Amazon rating
Amazon aggregate, one input among many in the Verdict Score
Based on 1 trusted source
Current price
$31.50
Updated May 17, 2026 · 1 min read
Sources behind this verdict
10 reviewers weighted by source trust
The consensus
What reviewers found
Synthesized across the trust-weighted source mix below.
Across the reviewers we read, the NGK LKR7DIX-11S (93175) is the cleanest expression of the Iridium IX line in this candidate pool. The Amazon listing shows a 4.7-star average across more than 2,100 reviews, autozone.com's product page summarizes customer feedback as 'smoother engine operation' after install, and walmart.com verified-purchase reviewers echo the throttle-response claim. A high-trust r/MechanicAdvice thread frames Iridium IX's value proposition as edge retention — the fine-wire center electrode keeps a sharp spark longer than platinum — which matches how oreillyauto.com positions the line.
What reviewers liked
- 4.7 Amazon rating across 2,100+ reviews, corroborated by walmart.com and autozone.com customer summaries
- r/MechanicAdvice (high-trust) endorses Iridium IX edge retention vs. platinum
- r/subaruimpreza and r/Miata users report smoother idle and revs after switching
- Pre-gapped from factory according to retailer product pages
Where it falls short
- r/genesiscoupe thread documents a fitment dispute — part-number verification is essential
- Same NGK counterfeit risk on third-party Amazon listings flagged in r/MechanicAdvice
- Performance gains are modest — multiple community reviewers note no measurable power increase, just smoother running
- Sold in 4-packs, so V6/V8 owners need to buy multiple sets
Across the reviewers we read, the NGK LKR7DIX-11S (93175) is the cleanest expression of the Iridium IX line in this candidate pool. The Amazon listing shows a 4.7-star average across more than 2,100 reviews, autozone.com's product page summarizes customer feedback as 'smoother engine operation' after install, and walmart.com verified-purchase reviewers echo the throttle-response claim. A high-trust r/MechanicAdvice thread frames Iridium IX's value proposition as edge retention — the fine-wire center electrode keeps a sharp spark longer than platinum — which matches how oreillyauto.com positions the line.
Specialist-community sentiment is positive but measured. r/subaruimpreza and r/Miata threads describe smoother revs and no MPG loss after switching, with one Miata owner specifically saying the 'butt-dyno' didn't register more power but the engine revved more cleanly. r/genesiscoupe surfaces a fitment dispute (dealer told the owner the plug didn't fit), reinforcing that part-number-to-engine matching matters more than brand reputation.
The pattern across mainstream reviewers and mechanic subreddits is consistent: this is a well-priced, well-stocked Iridium IX SKU with strong real-world feedback, provided buyers confirm fitment and source from a reputable seller given the broader NGK counterfeit problem.
- Designed specifically for the performance enthusiast, Iridium IX offers extreme ignitability, improved throttle response
- The 0.6 millimeter laser welded fine Iridium tip ensures high durability and a consistently stable spark and the tapered ground electrode minimizes electrical quenching effect
- Longer insulator , the corrugated ribs on insulator prevents flashover, and a triple gasket seal eliminates combustion gas leakage
- Iridium alloy has extremely high melting point, giving it high durability to heat and electrical wear, perfect for today's high performance engines
- Trivalent Metal Plating provides superior anti-corrosion and anti-seizing properties. Resistor Value-5K Ohm. Hex Size-5/8 inch
Iridium lasts longer than platinum. They key to spark plug performance is its ability to maintain a sharp edge on the center and side electrodes.
It offers excellent performance and no negligible loss of MPG. The fact that it was recently returned to like new performance with a spark plug ...
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“NGK LKR7DIX” · 11S Iridium IX 93175 Review
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