GM's 2014 1500 pickups earned the highest possible "overall" crash rating of five stars from the NHTSA, but that doesn't mean their full-size lineup is as safe as it could be.

The NHTSA gives up to five stars for "Frontal Crash," "Side Crash," and "Rollover" performance from which they create an "Overall" score.

1500's in all cab sizes and drivetrains received five stars on frontal and side crashes, four stars on rollovers.

2500 regular cabs only earned two stars overall, with two stars on frontal and side ratings. 4WD variants scored slightly higher in rollovers than RWDs, for four and three stars respectively. Crew cabs performed better on frontal impacts and much better on side impacts.

While the 2500 is bolstered to carry an additional ton over its rear axles and tow much more than that over the 1500, there don't seem to be differences in impact reinforcement up front.

Unfortunately the NHTSA reports don't present data on the two models in the same format, but after watching the frontal impact videos of both trucks it looks like the 2500 carries greater momentum through the crumple zone. That would explain why crash test dummies returned greater bodily injuries in the heavier trucks.

Silverado and their Sierra equivalents received the same rating in each category. Heavy-duty 3500 models have not been ranked by the NHTSA, but you can research details on the 1500s and 2500s .

MY2014 GM trucks have already been issued for head restraints with "excessive play" that failed to properly protect occupants from head injuries in collisions (trucks built 8/1/2013 to 9/10/13) and improperly welded airbag mounts that can cause inflation mounts to direct gas into the instrument cluster instead of the bag (trucks built 6/4/13 to 6/30/13).

Crashworthiness of the 1500 Silverado and Sierra impressed evaluators and represents a strong step forward in pickup safety. But It seems GM experienced some biased toward their most popular model and neglected to bring the heavy duty trucks up to the same standard. They're obviously capable of building a safe truck, now let's hope they start applying more innovation to the lower performers

Images: General Motors, NHTSA