Once a year, in a ritual that almost nobody outside the auto industry has heard of, the supply chain flips the script. More than 700 of the most powerful supplier executives sit down and grade the companies that buy from them. This year, the results proved that being a customer of choice is a competitive advantage.
Plante Moran's North American Automotive OEM-Supplier 2026 Working Relations Index recorded improvements at every OEM for the first time in the study's 26-year history. The index, which surveys Tier 1 suppliers and includes 78 of the Top 100 in North America, looks at how the six automakers actually behave across 2,348 buying situations.
This is the published version of a judgment every supplier makes silently, in every industry, every week. Buyers run scorecards on suppliers. Suppliers run one back and don't publish it. They price it through lead times, tooling quotes, change-order posture, risk premiums, and account staffing.
The grade has a name: customer of choice
The automotive numbers are the best proof anyone has assembled that the silent grade turns into cash. Researchers took 13 years of working relations data and laid it against the carmakers' own financials, and the link came back causal rather than coincidental. On average, something close to half the profit a manufacturer earned on each vehicle was not traced to its internal genius but to the state of its supplier relationships.
But handle that figure carefully.
It does not mean charm is half the job. It means profit hides in a place most executives never think to look: in the operating system running between the two companies, the connective tissue that suppliers are already pricing whether or not anybody bothers to measure it.
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The clearest example is from the 2021 microchip shortage. Here, the invisible grade became visible production numbers. Yet, as this was unfolding, Toyota spent a decade requiring key suppliers to stockpile 2-6 months of chips under the continuity plan it built after the devastating 2011 Fukushima earthquake. Reuters reported that one electronics supplier was contractually committed to holding at least four months of semiconductors for Toyota specifically. So, during this crisis, while other competitors idled plants, Toyota kept building and building and building. And ultimately, it took the U.S. sales crown from GM in 2021, the first year GM had lost it since 1931.
But here is the strange asymmetry at the core of all this. Yes, supplier scorecards are everywhere. And measurement running the other direction is so rare. But the silence does not exist because suppliers have nothing to say. In fact, this year's index pulled in more than 10,000 written comments from supplier executives. The feedback was specific and detailed.
And the payoff for asking carries a number too. Across over 100 large organizations, McKinsey found the companies that were collaborating regularly with their suppliers grew faster, ran leaner, and earned more than their industry peers.
Measuring what you can’t see
If you want to measure your own grade, it does not require a 26-year survey. It requires segmentation and strategic bottlenecks and launch-critical suppliers get watched hard. Competitive, high-spend categories kept being honest, and true commodities get no bureaucracy at all.
So how do you actually measure this?
First, ask your suppliers directly, once a year, and score it at the buying-team level, not by the company logo. Two questions do the heavy lifting: would you allocate scarce capacity or your strongest people to us ahead of comparable customers? And what single behavior would improve this account fastest?
Second, watch who stops bidding; your best suppliers rarely complain. They just go quiet on your RFQs, so track decline rates like a subscription company tracks churn.
Third, run reviews both ways, where the supplier shows up ready to grade you.
And fourth, look at your own behavior in the numbers: how you pay against terms, how long your quotes take, how often you spring late engineering changes, how often you're expediting. That stuff is a lot harder to fake than a survey.
Takeaway lessons
Hardball still works in liquid markets. For corrugated boxes, standard fasteners, and spot buys where capacity is plentiful and switching costs are near zero. The grade prices are only where something is genuinely scarce. Custom semiconductors, castings, battery materials, constrained tooling, and launch-critical engineering. The catch is that almost everything keeping a modern procurement chief awake at night already sits on that scarce list.
Raising the grade isn't free. The 2026 improvement is credited to OEMs fairly sharing tariff and EV-cost pain instead of pushing it downstream. The 2026 results demonstrate that every carmaker that changed its behavior got regarded within a single survey cycle.
The grade moves and suppliers are watching what you do now, not nursing a grudge from three years ago. So, ask your top suppliers this quarter how you score on payments, on forecasts, and on the speed of your decisions. Then receive their answers the way you fully expect them to receive your scorecard of them. Ultimately, the grading has been running for exactly as long as you have been buying anything. The only real choice left is whether you ever read it.
