Reddit appears in 14.7% of Gemini's sourced answers to car questions, more than any other website, against 0.3% of ChatGPT's. ChatGPT's top car source is Consumer Reports, which Gemini never cites, and no website reaches 7% of all sourced answers.
Analysis of 780 AI answers to 195 car questions · ChatGPT and Gemini, September 2026
Key Findings
- 1.Reddit is Gemini's most-cited source for car questions, appearing in 14.7% of its sourced answers, against 0.3% of ChatGPT's.
- 2.ChatGPT cites consumerreports.org in 10% of its sourced answers to car questions, while Gemini never cites it.
- 3.consumerreports.org is the most-cited website in AI answers to car questions at 6.7% of sourced answers, the lowest top-source share of 12 industries.
- 4.Gemini answers 52.8% of car questions without citing any source, against 2.3% for ChatGPT.
- 5.Companies and other commercial websites take 63.8% of the citations in AI answers to car questions, and government and university websites 11.4%.
Summary
A buyer comparing two used SUVs asks an AI assistant which is more reliable. On ChatGPT, the answer cites Consumer Reports, Car and Driver and the insurance regulators' association. On Gemini, when it cites anything, the most likely source is a Reddit thread.
Dealers, carmakers, parts retailers and auto publishers compete for citations alongside those sources. A citation is the link an AI answer shows as its evidence, and it is one of the few ways an answer sends a reader to a website. Knowing which sites win them, on which engine, shows an automotive business where it can realistically be named.
Reddit appears in 14.7% of Gemini's sourced car answers and 0.3% of ChatGPT's. The engines barely share a source list, and across both, the top website, consumerreports.org, reaches only 6.7% of sourced answers, the flattest leaderboard of any industry measured.
What we measured
On September 23, 2026 we asked ChatGPT and Gemini 195 car questions, each twice, as part of a wider study of AI sources across 12 industries. That gave 780 answers, 565 of which cited at least one source, and 642 different websites were cited across them.
A website's share is the percentage of sourced answers that cite it at least once, counting all pages from the same site together. We also sorted every citation by the kind of website behind it: government and education (.gov, .edu and .mil addresses), nonprofits and associations (.org), media and reference publishers, user-generated sites such as forums, social media and video platforms, and companies and other commercial websites. The same measures were taken for the other 11 industries.
ChatGPT and Gemini cite different sites
Gemini's list is led by Reddit and Wikipedia (12%), neither of which ChatGPT leans on: it cites Reddit in 0.3% of its sourced car answers and Wikipedia in 3.4%. ChatGPT's leaders are Consumer Reports (10%) and the National Association of Insurance Commissioners' naic.org (8.4%), and Gemini cites neither. The top two car sources on each engine are rare or absent on the other.
Source: Suff Digital analysis of 780 AI answers to 195 car questions · ChatGPT and Gemini, September 2026
| Measure | ChatGPT | Gemini |
|---|---|---|
| Answers with no source | 2.3% | 52.8% |
| Websites per sourced answer | 3 | 3.3 |
| Most-cited website | consumerreports.org | reddit.com |
| Share of sourced answers citing it | 10% | 14.7% |
Gemini also cites far less often. ChatGPT cites a source in 97.7% of car answers and lists 3 websites on average. Gemini cites a source in 47.2%, so more than half its car answers give the reader nothing to click. Across both engines, 27.6% of car answers cite nothing, almost all from Gemini.
No website owns car answers
That is the lowest top-source share of the 12 industries in the study; in fitness, the leader reaches 41.5%. The rest of the car list is a mix of every kind of site: Wikipedia (6.2%), naic.org (5.7%), Reddit (5%), Car and Driver (4.8%), the parts retailer AutoZone (4.4%), the Department of Energy (3.7%), Toyota (3.5%) and the National Highway Traffic Safety Administration (3.2%).
Source: Suff Digital analysis of 780 AI answers to 195 car questions · ChatGPT and Gemini, September 2026
| Rank | Website | All answers | ChatGPT | Gemini |
|---|---|---|---|---|
| 1 | consumerreports.org | 6.7% | 10% | 0% |
| 2 | wikipedia.org | 6.2% | 3.4% | 12% |
| 3 | naic.org | 5.7% | 8.4% | 0% |
| 4 | reddit.com | 5% | 0.3% | 14.7% |
| 5 | caranddriver.com | 4.8% | 6.3% | 1.6% |
| 6 | autozone.com | 4.4% | 6% | 1.1% |
| 7 | engineerfix.com | 3.7% | 5.5% | 0% |
| 8 | energy.gov | 3.7% | 5.2% | 0.5% |
| 9 | global.toyota | 3.5% | 5.2% | 0% |
| 10 | nhtsa.gov | 3.2% | 4.7% | 0% |
| 11 | progressive.com | 3% | 2.4% | 4.3% |
| 12 | kbb.com | 3% | 2.4% | 4.3% |
| 13 | cms.gov | 2.7% | 3.4% | 1.1% |
| 14 | iii.org | 2.7% | 3.4% | 1.1% |
| 15 | mercedes-benzcaribbean.com | 2.7% | 2.1% | 3.8% |
Carmakers get cited directly. Toyota, Mercedes-Benz, Ford and Stellantis each appear in about 2% to 4% of sourced answers, and insurance sources such as Progressive (3%) and the Insurance Information Institute (2.7%) show up alongside Kelley Blue Book (3%). A flat list means no brand is locked in, and a well-built page on a specific car question can win the citation.
How cars compare with other industries
Companies and other commercial websites take 63.8% of car citations, nonprofits and associations (.org) 12.3%, and government and university websites 11.4%, 9th of 12 industries for official sources. User-generated content, meaning forums, social media and video, takes 2.9%.
Cars sit in the commercial half of the table, alongside travel and software, but unlike them no single company dominates: software's top source reaches 24.3% of sourced answers and travel's 13.2%, against 6.7% for cars.
Source: Suff Digital analysis of 780 AI answers to 195 car questions · ChatGPT and Gemini, September 2026
| Industry | Top source | Share of sourced answers | Government and university share | User-generated share |
|---|---|---|---|---|
| Legal | americanbar.org | 14.7% | 20.6% | 3.8% |
| Health | nih.gov | 32.3% | 36.2% | 0.6% |
| Money | irs.gov | 13.8% | 30.2% | 1.7% |
| Real estate | consumerfinance.gov | 27.2% | 26.9% | 1.6% |
| Home improvement | energy.gov | 11.8% | 39.2% | 1.6% |
| Travel | delta.com | 13.2% | 8.1% | 2.8% |
| Cars | consumerreports.org | 6.7% | 11.4% | 2.9% |
| Software | apple.com | 24.3% | 4.7% | 3.2% |
| College | consumerfinance.gov | 13.1% | 32.1% | 2.1% |
| Fitness | nih.gov | 41.5% | 45.5% | 0.2% |
| Pets | vcahospitals.com | 18.4% | 10.1% | 3.1% |
| Recipes | usda.gov | 37.5% | 31.8% | 2.1% |
What this means for dealers and automotive brands
With no dominant source, car questions are winnable. Publish clear pages on the specific questions buyers ask: running costs and insurance costs by model, known faults and recalls, towing and cargo figures, trim-by-trim differences. State the numbers plainly and date them, so an AI engine can quote them with confidence.
Plan for Reddit on Gemini. Owners discussing your models there shape what Gemini repeats, so answer questions publicly where it is appropriate and make sure your own pages address the complaints that come up in those threads. On ChatGPT, your pages are cited alongside Consumer Reports, Car and Driver and insurance sources, so match their specific, well-sourced detail. An automotive seo program built around buyer questions covers both.
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<p style="font:14px/1.5 system-ui,sans-serif">Source: <a href="https://www.suffdigital.com/resources/data-studies/ai-sources-car-questions">Reddit Is Gemini's Top Source for Car Questions at 14.7% vs 0.3% on ChatGPT - Suff Digital</a></p>
Cite this study
Suff Digital. (2026). Reddit Is Gemini's Top Source for Car Questions at 14.7% vs 0.3% on ChatGPT. https://www.suffdigital.com/resources/data-studies/ai-sources-car-questions
Reddit Is Gemini's Top Source for Car Questions at 14.7% vs 0.3% on ChatGPT - Suff Digital - https://www.suffdigital.com/resources/data-studies/ai-sources-car-questions
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