If you’re in the market for General Motor’s 2015 Chevrolet Silverado HD or GMC Sierra HD trucks and don’t want to drop the coin for the Duramax-Allison powertrain combo, then we have some good news: GM has bumped the advertised horsepower rating of the 6.0L V8 in its one-ton heavy duty pickups from 322 hp to 360 hp.
According to USA Today, GM made the decision to bump the horsepower rating after finding that the 3500 HD trucks could pass government noise regulations while the engines were revving higher. One-tonne pickups fall into a category that requires them to meet a “pass by” noise regulation. To control the noise, automakers sometimes have to keep the engine in lower RPM ranges during pass-by testing. The automaker can then only advertise the horsepower the engine is making at the reduced speed, even though the engine is capable of producing more power.
The same rules do not apply for the three-quarter-ton 2500 HD Silverado and Sierra models, as they are in a different category.
“No longer do we need to ‘de-rate’ the full-size pickups, as we have done for over 20 years, because new technology and design make them quiet enough at full power to pass the noise test,” GM powertrain spokesman Tom Read told USA Today. As a result, “we are revising our information for the 2015 model year,” he said.
The heavy-duty Chevrolet Silverado 3500 and GMC Sierra 3500 will go on sale in Q1 of 2014 as 2015 models.