The Society of Automotive Engineers plans to create a single benchmark for measuring towing performance, an issue that for years has been a bone of contention among auto makers.

The latest flare-up comes as truck rivals Ford Motor Co. and General Motors Corp. bring their heavy-duty, or Class 2 and Class 3, pickups to market.

GM claims towing capacity of 13,000 lbs. (5,897 kg) on the '07 three-quarter and 1-ton Chevrolet Silverado and GMC Sierra, which are now in full production.

Ford last year unveiled its '08 Super Duty lineup, including the F-450, which offers towing capacity in excess of 24,000 lbs. (10,000 kg).

Gary White, GM vice president and vehicle line executive-fullsize trucks and SUVs, says he has concerns with some competitors' truck-hauling claims.

Careful not to single out Ford's new F-450, which White hasn't driven, he says “real-driving situations” show advertised towing claims may be overblown.

As a result, GM petitioned SAE to develop a uniform standard to measure towing. SAE now plans to devise a uniform benchmark but says its decision to pursue a new guideline was based on “broader industry need, not just one party's.”