In 2005, the Society of Automotive Engineers introduced a new test procedure (J2723) for engine horsepower and torque. The procedure eliminates some of the areas of flexibility in power measurement, and requires an independent observer present when engines are measured. The test is voluntary, but engines completing it can be advertised as "SAE-certified".

Many manufacturers began switching to the new rating immediately, often with surprising results. The rated output of Cadillac's supercharged Northstar V8 jumped from 440 hp (328 kW) to 469 hp (350 kW) under the new tests, while the rating for Toyota's Camry 3.0 L 1MZ-FE V6 fell from 210 hp (157 kW) to 190 hp (142 kW). The first engine certified under the new program was the 7.0 L LS7 used in the 2006 Chevrolet Corvette Z06. Certified power rose slightly from 500 hp (373 kW) to 505 hp (377 kW)."

This latest version of J1349 (J2723) will not cut everyone’s engine ratings. The first engine certified to meet the revised standard is the Corvette Z06’s LS7, and it actually received a five horsepower increase to 505. The revision to J1349 will account for new engine technologies and reduce the opportunity for liberal interpretation. By having a neutral third-party SAE witness certify an engine’s output, automakers can help dispel doubts and win customer confidence.

The new certification standard is voluntary. So far, General Motors is the only automaker that “plans to certify every new or significantly revised engine in the future." Ford does not have any plans to certify its engines, and Chrysler is still considering whether to certify all engines or just high-performance motors.

The first engine certified under the new program was the 7.0 L LS7 used in the 2006 Chevrolet Corvette Z06. Certified power rose slightly from 500 hp to 505 hp after adding the "Z06" sticker to the front fenders.