2 of 7
GMC Sierra/Chevrolet Silverado
Front impact: Good
Side Impact: Poor
Whiplash protection: Acceptable
Stability Control: Optional
Top Safety Pick: No

While they earned the top grade of "Good" for front-crash protection, General Motors big trucks got a "Poor" rating from the Insurance Institute for side-impact protection.

The problem, according to the Institute, is a weak side structure combined with the absence of body-protecting side airbags. These trucks do have head-protecting side airbags and those worked well, but those airbags don't protect ribs and internal organs.

The Silverado and Sierra earned top ratings for both front and side impact protection from the federal government's National Highway Safety Administration, which uses different tests from those used by the Insurance Institute.

"IIHS tests are valid and we do pay attention to them," GM said in a statement responding to the Insurance Institute, "but it's also important to understand the results of a single test do not determine whether a vehicle is safe or not."

GM will be making changes to these trucks for the 2010 model year that will allow them to perform better on the Insurance Institute's tests, a GM spokeswoman said separately.

NEXT: Nissan Titan

Last updated February 11 2009: 12:23 PM ET
More Galleries
17 cool gadgets that tease the future Smart telescopes, surveillance for dogs, an electric roadster and more from CES 2018. More
These 12 airplane beds let you really sleep on a flight For the price of a premium class ticket, you may just get a space that's comfortable, private, and quiet enough to ensure a good rest. More
CES 2018 kicks off with oddball gadgets The biggest tech show of the year opened with a collection of quirky gadgets. More

Special Offer