Auto Warranty: AI Market Discovery Index

Benchmark Summary

Endurance leads the Auto Warranty AI Market Discovery Index in September 2026 with valid recommendation coverage of 84.0%. That figure moved down from August 2026's 88.8%, a decline of 4.8 points that the benchmark flags as beyond normal variation, yet Endurance remains the category leader. Since the May 2026 baseline, when Endurance held 0.0% coverage, the brand's rise to 84.0% is a significant increase of 84.0 points. CarShield ranks second in September 2026 at 75.0%, a 9.0-point gap behind Endurance.

CarShield recorded the largest coverage increase, rising 6.7 points from 68.3% in August 2026 to 75.0% in September 2026. CARCHEX recorded the largest decline, falling from 80.5% in August 2026 to 73.2% in September 2026 (Down 7.3 points), a change the benchmark flags as beyond normal variation. Eight brands — American Dream Auto Protect, CARCHEX, CarShield, Endurance, everything breaks, Olive, Omega Auto Care, and Toco Warranty — moved significantly on valid recommendation coverage since the May 2026 baseline. No tracked brand qualified as a significant decliner over the full series, though CARCHEX, Endurance, Omega Auto Care, and Toco Warranty each declined in two consecutive months.

The benchmark began with 800 prompt-surface observations in September 2026 and produced 679 qualified observations after qualification.

Current Benchmark at a Glance

The July 2026 intermediate month saw qualified observations at 610 and a leader coverage of 89.7%, while August 2026 held qualified observations at 625.

Qualified surface breadth counts the canonical AI/search surface families with at least one qualified observation. The six families in this benchmark are ChatGPT, Copilot, Gemini, Perplexity, AI Overviews, and AI Mode. September 2026 covered all six.

For the strategic interpretation of this benchmark, read CiteWorks Studio's analysis of How AI Search Is Recommending Auto Warranty

Research Scope and Qualification

The public benchmark uses a narrower set of observations than the raw collection universe. The qualification funnel for each month is below.

Brand-level percentages use the qualified observations as the public denominator, not the raw collection. For September 2026, the 679 qualified observations derive from 800 source prompts after removing 20 irrelevant and 101 reserved observations. See the AI Market Discovery Methodology for the full qualification rules.

Current Brand Standings

The table below shows the primary current-month benchmark view for September 2026, sorted by valid recommendation coverage.

How to Read the Standings

• Presence rate: Share of qualified observations where the brand is mentioned at all.
• Valid recommendation coverage: Share of qualified observations where the brand appears in a recommendation-shaped answer that includes a valid, actionable recommendation.
• Top-three rate: Share of qualified observations where the brand is recommended within the top three positions.
• Rank-one rate: Share of qualified observations where the brand is recommended in the first position.
• Net sentiment: Positive minus negative mention share, scaled to a 0 to 1 range.

For formulas and denominator rules, see AI Market Discovery Metric Definitions.

Recommendation Coverage Movement

Several brands showed notable August-to-September moves beyond normal variation. CARCHEX declined from 80.5% in August 2026 to 73.2% in September 2026 (Down 7.3 points), continuing a two-month decline that began in July 2026. Omega Auto Care declined from 24.5% in August 2026 to 19.6% in September 2026 (Down 4.9 points). Toco Warranty declined from 14.4% in August 2026 to 9.1% in September 2026 (Down 5.3 points). Endurance moved down from 88.8% in August 2026 to 84.0% in September 2026 (Down 4.8 points).

Largest Increase: CarShield

CarShield's valid recommendation coverage rose from 68.3% in August 2026 to 75.0% in September 2026 (Up 6.7 points), a change the benchmark flags as beyond normal variation. Since the May 2026 baseline of 29.4%, the brand has risen 45.6 points. The brand was present in 91.2% of September 2026 qualified observations and appeared in the top three in 63.5% of them.

Largest Decline: CARCHEX

CARCHEX's valid recommendation coverage declined from 80.5% in August 2026 to 73.2% in September 2026 (Down 7.3 points), a move beyond normal variation. Coverage also declined in the prior month, from 81.8% in July 2026 to 80.5% in August 2026. Despite the two-month decline, CARCHEX's coverage remains well above its May 2026 baseline of 30.2%, holding at 73.2% in September 2026.

Category Leader: Endurance

Endurance led the category in September 2026 with valid recommendation coverage of 84.0%, ahead of CarShield at 75.0%. Endurance also led on presence (99.9%), top-three rate (80.8%), and rank-one rate (77.8%). The brand's coverage declined in each of the two months since July 2026, moving from 89.7% in July 2026 to 84.0% in September 2026, while remaining the category leader throughout.

Recommendation Placement Snapshot

Coverage alone does not show how prominently a brand is recommended. The table below shows placement among the top three and first-position recommendations for the leading brands in September 2026 alongside their May 2026 baselines.

Close coverage can still hide different first-position rates. Endurance and CARCHEX both appeared in the top three in the large majority of observations, but Endurance took the first position in 77.8% of September 2026 observations, while CARCHEX took the first position in only 0.6%.

Buyer-Intent Distribution

In September 2026, all qualified observations fell into the brand recommendation class. The public series for this month measures that class of discovery and does not yet contain qualified observations in the pricing and value or multi-brand comparison classes.

Historical Measurement Record

New measurements are added to the same evergreen benchmark report.

Evidence and Source Layer

The benchmark is built from prompt-level observations that retain the query, AI/search surface, answer, brand outcome, recommendation placement, sentiment, and, where exposed, citations or attributable evidence sources. Source presence is evidence about the information environment. It is not automatically proof that the source caused the recommendation.

Scope Boundaries

This public benchmark does not measure market share, attributable sales, every possible AI response, organic-search ranking, social mention volume, private or sponsored channels, or causality from a metric movement alone.

About This Benchmark

The LLM Authority Index AI Market Discovery Index provides a neutral, observation-based view of how AI and search surfaces recommend and present brands across a vertical. The Auto Warranty benchmark tracks 12 brands across six canonical AI/search surface families using a fixed qualification protocol.

• AI Market Discovery Methodology
• AI Market Discovery Metric Definitions
• AI Market Discovery Research Standards
• Modeled AI Authority Value

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The public industry benchmark shows category-level standings. A company-level Authority Index can go deeper. The public percentage cannot identify the prompts, competitors, or sources causing the result.

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