Despite a tough pricing environment, suppliers delivered the industry's best shareholder returns in the first quarter, up 5.0 percent.
All 41 global parts suppliers posted a positive return in the 12 months that ended March 31, averaging a 63.5 percent gain.
Clarion Co. Ltd. turned in the weakest return in the period, though still up 3.9 percent.
"Suppliers continue to demonstrate their ability to cut costs, but they can't cost save themselves forever," says Mike Burwell, a partner with PricewaterhouseCoopers.
He stressed that suppliers need a diverse customer base and must have production in low-cost countries.
Tenneco Automotive Inc. shot into the top spot for every period. It rose 89.7 percent in the first quarter, 461.3 percent for the 12 months and 353.1 percent for the three years.
"Contributing to the results is the company's focus on emissions systems, a business that will benefit from increased regulation demanding more environmentally friendly cars," PricewaterhouseCoopers says in its analysis of the rankings. "And management has sought to increase the percentage of materials purchased from low-cost countries."
Tower Automotive Inc. provided the worst return in the quarter, down 26.2 percent. "It's more related to the fact that they'd come so far in the quarter before and they gave back some of those gains," says Dave Hiemstra, a senior associate at PricewaterhouseCoopers.
The supplier delivered a 51.7 percent return in the quarter that ended Dec. 31.
Goodyear Tire & Rubber Co. had the worst three-year return, down 61.8 percent.
Burwell attributed the performance to the weak tire business and a recent Securities and Exchange Commission investigation of the tire supplier.