Toyota Leads 2026 North American OEM Supplier Relations Study Amid Industry Cost Pressures

The 2026 edition of the North American Automotive OEM-Supplier Working Relations Index (WRI) released by Plante Moran on May 18 showed a rare industry-wide improvement across all six major automakers evaluated in the study. The report highlighted that every major OEM operating in North America improved its supplier relationship scores for the first time in the survey’s 26-year history. Despite ongoing tariff uncertainties and rising electric vehicle cost pressures, suppliers reported stronger perceptions regarding profitability potential, communication quality, buyer interactions and commercial fairness among manufacturers.

The study indicated that purchasing teams at automakers concentrated heavily on relationship management areas that remained under their direct influence. Since many procurement teams had limited authority over how tariff burdens and EV-related costs were shared between suppliers and manufacturers, they focused on transparency, supplier engagement and operational coordination. These efforts appeared to improve supplier sentiment even as the automotive industry continued to face increasing electrification expenses and supply chain complexity.

Among the automakers assessed, Toyota continued to lead the rankings with a score of 409 points, reflecting an improvement of 23 points compared with the previous year. Honda retained second place with 360 points after gaining 13 points. General Motors remained third with 318 points, increasing by eight points from last year’s survey results. The study showed that while rankings remained unchanged, the score improvements across all manufacturers reflected stronger supplier engagement efforts throughout the sector.

2026 North American OEM-Supplier Working Relations Index Rankings

The following table summarizes the latest WRI performance scores and year-over-year improvements recorded by the six major automotive manufacturers included in the study.

Nissan continued to hold fourth place with 255 points after a moderate six-point improvement. Ford posted the largest gain in the study, improving by 32 points to reach 223 points overall. Although the company remained fifth in the rankings, the improvement reflected stronger supplier perceptions related to fairness and engagement. Stellantis, while remaining at the bottom of the rankings, also recorded a significant 22-point improvement compared with the prior year.

Plante Moran collected and analyzed 750 responses from executives representing Tier-1 automotive suppliers serving the six OEMs evaluated in the report. The survey response count increased from 665 submissions recorded in 2025, indicating broader supplier participation this year. Responses were gathered from March through mid-April and covered several operational categories, including communication effectiveness, buyer behavior, profitability expectations, trust levels and commercial fairness across procurement operations.

The study also highlighted several areas where manufacturers made targeted progress. Ford and Stellantis achieved the largest gains in commercial fairness metrics, while Toyota and Honda continued to lead initiatives designed to help suppliers reduce operational costs. General Motors demonstrated the strongest improvements in covering sunk costs and EV-related cost recovery support. However, the company also faced criticism from suppliers regarding certain supply chain resiliency initiatives that were viewed as adding operational pressure.

Toyota and Honda maintained leadership positions in supplier trust and communication quality throughout the study period. Suppliers responding to the survey continued to rate both automakers highly for transparency, collaboration and long-term relationship stability. The findings suggest that relationship management remains a critical competitive factor for automotive manufacturers navigating ongoing electrification investments, supply chain risks and rising production costs across the North American automotive industry.

Frequently Asked Questions

What is the North American Automotive OEM-Supplier Working Relations Index?
The North American Automotive OEM-Supplier Working Relations Index is an annual study conducted by Plante Moran to measure supplier relationships with major automotive manufacturers. The report evaluates areas such as communication quality, commercial fairness, profitability potential, buyer effectiveness and trust between OEMs and Tier-1 suppliers. The 2026 study analyzed 750 supplier executive responses covering Ford, General Motors, Honda, Nissan, Stellantis and Toyota, providing insight into how suppliers perceive operational and strategic relationships across the automotive industry.

Which automaker ranked highest in the 2026 WRI study?
Toyota ranked highest in the 2026 North American Automotive OEM-Supplier Working Relations Index with a total score of 409 points. The company improved by 23 points compared with the previous year and continued to lead in supplier communication, trust and cost-reduction collaboration. Honda secured second position, while General Motors remained third. Despite strong score improvements by Ford and Stellantis, the overall ranking order among the six manufacturers remained unchanged from the previous year’s results.