U.S. online auto parts sales reached $44.6 billion in 2025, including third-party marketplaces.
The Auto Care Association's 2025 Joint E-commerce Trends and Outlook Forecast breaks that figure into two channels: roughly $23 billion from direct ecommerce (brand sites, independent retailers, and first-party Amazon), and $44.6 billion when third-party marketplace volume is included. The gap between those numbers reflects how much of the market still flows through Amazon and eBay rather than owned channels.
B2B marketplace sales accounted for nearly half of U.S. online auto parts revenue in 2024.
BigCommerce reports that B2B transactions made up roughly $20.7 billion of the $42.4 billion in total U.S. online auto parts revenue in 2024. That share has grown each year since 2020, as repair shops, fleet managers, and distributors shifted procurement online. The channel is no longer consumer-dominant and brands treating it as such are missing a significant portion of addressable demand.
The U.S. auto parts ecommerce market is on track to reach $211.42 Billion by 2029 according to Research and Markets.
The global e-commerce automotive aftermarket sat at $96.81 billion in 2024 and is projected to reach $211.42 billion by 2029, growing at a compound annual growth rate of nearly 17%. The shift is structural, not cyclical. Subscription-based parts services, rising EV component sales, and growing buyer comfort with spec-driven purchases online are all pulling demand in the same direction.
The global automotive ecommerce market is projected to grow from $135.14 billion in 2026 to $440.83 billion by 2034.
Fortune Business Insights places the global automotive ecommerce market (encompassing parts, accessories, and vehicle transactions) at $116.24 billion in 2025 and $135.14 billion in 2026, with a projected CAGR of 15.93% through 2034. North America led with a 32.79% share in 2025.
The global e-commerce automotive aftermarket reached $256.31 billion in 2025.
Research Nester separates the aftermarket-specific figure (parts and accessories only, excluding new vehicle transactions) at $256.31 billion in 2025, with a 14.3% CAGR projected from 2026 through 2035.
Note on market size figures: Methodology differences between research firms produce a wide range of estimates. The figures above reflect the most frequently cited sources. Hedges & Company's U.S.-specific figures, grounded in Census Bureau data and industry interviews, are the most operationally reliable for North American market planning.
Regional breakdown of global automotive ecommerce market (2025):
Source: Fortune Business Insights
The global automotive ecommerce market is growing at a CAGR of 15.93% through 2034.
That growth rate outpaces overall global ecommerce (projected at roughly 6.84% CAGR through 2030) by a significant margin. The structural driver is aging vehicle fleets in North America and Europe, where deferred new vehicle purchases during supply chain disruptions extended the average ownership cycle and increased demand for maintenance and repair parts.
The average age of U.S. vehicles reached 12.6 years in 2024.
S&P Global Mobility reports the U.S. vehicle-in-operation (VIO) average age hit 12.6 years in 2024, up from 11.9 years in 2019. An older fleet generates higher parts replacement frequency. Particularly in categories like brakes, suspension, electrical components, and engine parts where wear patterns are predictable and demand is non-discretionary.
The U.S. light-duty automotive aftermarket reached $413.7 billion in 2024 and is projected to surpass $500 billion by 2028.
The U.S. light-duty aftermarket grew 5.7% in 2024 to $413.7 billion, with an additional 5.1% growth projected for 2025. The light-duty segment is forecast to top $500 billion by 2028. Reaching that threshold just four years after crossing $400 billion. The total U.S. aftermarket, including light, medium, and heavy-duty vehicles, is projected to reach $664.3 billion by 2028.
The SEMA specialty equipment market hit a record $52.65 billion in consumer sales in 2024.
The SEMA 2025 Market Report places the U.S. specialty equipment market (covering performance parts, accessories, and customization products) at $52.65 billion, a 1% increase over 2023's $52.3 billion. The segment maintained growth despite broader consumer spending headwinds, reflecting the durability of enthusiast purchase intent.
Half of specialty equipment buyers are under 40.
According to the 2024 SEMA Market Report, half of those modifying their cars and trucks are under the age of 40. Younger accessory enthusiasts are also more likely to take on more extensive builds, including suspension and engine performance modifications. They skew toward wheels, lighting, and appearance products, and are more likely than older buyers to order parts online and pick them up or have them installed in-store. With 20% of under-40 accessorizers using that mixed-mode shopping pattern in 2023.
Pickups, CUVs, and SUVs now account for the largest combined share of specialty equipment spending.
The platform shift from sedans and coupes to light trucks has reshaped the aftermarket category mix. These three vehicle types dominate modification and accessory spending, which has implications for product catalog prioritization, fitment data requirements, and the search terms that drive paid and organic traffic.
Over 90% of DIY auto parts buyers conduct online research before purchasing.
Hedges & Company places digital influence on DIY auto parts purchases at 90%. Meaning roughly nine in ten products sold to DIY and enthusiast consumers are influenced by online research before the transaction, regardless of where the final purchase occurs. The figure has grown steadily since 2017, when their own research placed it at 85%.
Consumers now split aftermarket spending nearly equally between online and offline channels.
SEMA's 2024 and 2025 research found that consumers have fully adopted mixed-mode shopping. Moving between online and brick-and-mortar channels based on product type, price point, and installation complexity. What this means operationally: the ecommerce channel captures a growing share of discovery and decision even when the transaction happens offline. A retailer without a strong online presence loses influence at the top of the funnel regardless of in-store conversion.
The percentage of consumers who start in-store purchase journeys online has grown steadily since 2018.
The Auto Care Association's 2025 Joint E-commerce Trends and Outlook Forecast documents this shift without quantifying the exact current percentage but the directional finding is consistent with Hedges & Company's digital influence data. Online is where the buying journey begins for most parts categories, including ones that ultimately transact at a counter or retail location.
DIYers are more likely to purchase from online-only sources than brick-and-mortar stores.
The Auto Care Association's 2025 forecast specifically notes that DIY buyers (those who install their own parts) show a stronger preference for online-only retailers (Amazon, eBay, RockAuto) relative to DIFM buyers, who are more likely to involve a professional installer and purchase through service channels.
The DIY/DIFM split is the most consequential segmentation variable in the aftermarket for ecommerce strategy. It determines category mix, catalog depth, conversion path, and margin structure.
Wheels and tires carry among the highest professional installation rates in the specialty equipment market despite strong online purchase activity.
According to the 2022 SEMA Market Report, DIY installation accounts for only 27% of off-road and oversize tire purchases and 25% for performance and specialty tires — meaning roughly 73–75% of buyers in those subcategories rely on a professional shop for mounting and balancing. The product transacts online but the customer relationship extends to the installer — a "buy online, install offline" dynamic that has implications for how brands and retailers think about the full purchase journey, not just the point of transaction.
DIFM purchasers skew toward complex components — exhaust, computers, emissions, suspension.
The Auto Care Association's e-tailing study draws a clear line between the two buyer types by category. DIYers concentrate in simpler, lower-complexity purchases like filters, glass, lighting, and electrical parts that are generally easier to install. DIFM purchases skew toward more complex parts: exhaust systems, engine computers, and emissions components. DIFM buyers are more likely to be Millennials purchasing for upgrades rather than routine maintenance. More tech-savvy, more active on social media during the research process, and more likely to buy on mobile.
Engine part ticket amounts grew at up to 6% CAGR from 2021 to 2025.
The Auto Care Association's 2025 forecast reports that average order values for engine parts grew at a CAGR of up to 6% from 2021 through 2025, though this growth is attributed primarily to inflation rather than volume increases. The implication: margin per transaction has held in nominal terms but pressure on unit economics is real for brands absorbing cost increases without equivalent price flexibility.
Fitment is where most auto parts ecommerce businesses leak revenue. The statistics here reflect structural issues that show up in feed suppressions, return rates, and conversion gaps, not just product availability.
Sites with comprehensive Year-Make-Model search consistently outperform those with basic search functionality.
Across SCUBE's work with automotive parts ecommerce clients, Year-Make-Model (YMM) compatibility search is the single feature most correlated with above-average conversion performance. Sites that implement it well see materially higher conversion rates than those that don't, often by a significant multiple. The gap reflects not just UX but data quality: YMM search only works if the underlying fitment data is accurate and complete. A well-designed fitment interface built on incomplete or inconsistent vehicle data produces the same buyer friction as having no fitment search at all.
A single part can require hundreds or thousands of individual fitment data points.
Spork Marketing documents the data complexity: a single SKU may require fitment data segmented by trim level, engine size, transmission type, drivetrain configuration, and model year — with variations that change year over year. For catalogs with 50,000+ SKUs, incomplete fitment data is not a minor QA issue; it's a structural cap on organic search visibility and paid campaign performance.
Digital fitment tools that use VIN-based lookup reduce returns and increase conversion.
Straits Research's automotive aftermarket analysis notes that digital fitment tools using VIN lookup and 3D scanning have measurably reduced return rates and increased conversion by closing the buyer confidence gap around compatibility. For high-SKU retailers, fitment accuracy is an acquisition cost issue as much as an operations issue. Wrong-part returns erode margin and customer retention simultaneously.
Third-party marketplaces account for roughly half of U.S. aftermarket ecommerce.
According to the Auto Care Association and MEMA Aftermarket Suppliers' Joint E-commerce Trends and Outlook Forecast, third-party marketplace sales (Amazon, eBay, and Walmart) reached $21.8 billion in 2024, against $22.3 billion from direct ecommerce retailers, putting marketplaces at approximately 49% of the $44.1 billion total U.S. aftermarket ecommerce market. That near-even split reflects both the breadth of Amazon's auto parts catalog and the search behavior of DIY buyers, who treat marketplace platforms as a default product discovery channel for straightforward replacement parts. For branded sellers, it also means competing on a platform where private-label alternatives have direct access to the same demand.
Amazon saw 7.5% year-over-year growth in automotive products sales between 2022 and 2023.
Auto Care Association data cited by SCUBE Marketing shows Amazon automotive product sales grew 7.5% YoY between 2022 and 2023. Specific subcategories (shocks/struts and floor mats) grew at 22% during the same period, reflecting the strength of consumable and commodity parts on the platform.
Amazon dominates in automotive lighting, accounting for 8% of their auto parts sales.
The concentration of Amazon's automotive share in lighting is a useful proxy for where marketplace advantages are strongest: high-volume, low-complexity, low-fitment-risk categories where price and delivery speed determine purchase. This is also where margin pressure is most acute for branded sellers competing against private-label alternatives.
Digital influence on U.S. auto parts and accessories is projected to reach $200 billion in 2026.
Hedges & Company projects total digital influence on the U.S. auto parts market, including both online transactions and offline purchases that began online, at $200 billion in 2026, up from $177 billion in 2023. This figure represents the share of total aftermarket revenue (online and offline) that was influenced by digital channels at some point in the purchase journey.
Paid search remains the dominant customer acquisition channel for auto parts ecommerce.
SCUBE Marketing's analysis of the automotive parts ecommerce category identifies paid search as the primary acquisition channel, ahead of organic, marketplace advertising, and social. The most effective paid search strategies organize campaigns by vehicle make and model, mirroring how buyers actually search, rather than by part type alone. This alignment between campaign structure and search behavior produces significantly higher conversion rates than generic keyword-to-product mapping.
Mixed-mode shopping is now the default, not the exception.
SEMA's 2024 and 2025 research confirms that consumers no longer follow a linear path from online research to online transaction. They research online, compare on marketplaces, call the retailer, visit a counter, and return for installation advice, often across multiple sessions and channels for a single purchase. Ecommerce infrastructure that supports only the direct transaction captures a fraction of the influence it could have.
The B2B channel is growing faster than B2C in the automotive aftermarket ecommerce market.
While B2C controlled the majority of the ecommerce automotive aftermarket in 2024 at roughly 67% of total revenue, the B2B segment is projected to expand at a 22.70% CAGR through 2030. Meaningfully outpacing B2C growth. In the U.S. specifically, B2B transactions accounted for approximately 35% of the $44.6 billion in automotive ecommerce sales in 2025, a clear signal that repair shops, distributors, and fleet operators are rapidly adopting digital procurement channels. These buyers expect the same platform functionality that consumer channels offer (VIN lookup, cross-referencing, bulk ordering, and account-based pricing) and brands without B2B-capable infrastructure are ceding this segment to intermediaries who have built for it.
SCUBE Marketing specializes in paid media and SEO for high-SKU, spec-driven ecommerce brands in the automotive aftermarket and adjacent industries. If your catalog exceeds 5,000 SKUs or your paid media structure was built for a simpler world, the SCUBE Game Plan is a free diagnostic that shows where spend is leaking and what a realistic path forward looks like.
