Supersize Me: 'Supersizing' vehicles offer minimal safety benefits, says IIHS study

Toronto, Ontario — A recent study on the crash compatibility of larger vehicles by the Insurance Institute for Highway Safety (IIHS) finds that so-called supersized vehicles provide minimal safety advantages compared to smaller ones.

The study indicates that for vehicles weighing less than the North American fleet average, the risk of occupant fatalities decreases significantly with each additional 500 pounds of weight. However, this benefit diminishes for vehicles exceeding the average weight of 4,000 pounds, as the IIHS reports a minimal reduction in risk for occupants associated with additional weight.

In terms of impact on other road users, adding 500 pounds to a lighter-than-average vehicle presents hardly any increased risk. Conversely, the same weight increase in a heavier-than-average vehicle escalates the danger for others on the road.

The study also highlights that between 2017 and 2022, heavy SUVs were 20 percent more likely than lighter vehicles to contribute to fatalities for other vehicle occupants. For pickup trucks, the likelihood of causing fatalities for other motorists was found to be two-and-a-half times greater than that of cars for models from 2011 to 2016. This figure decreased to just under twice as likely for models from 2017 to 2022.

For vehicles weighing less than the average of 4,000 pounds, each additional 500 pounds in curb weight resulted in a further reduction of driver fatality rates by 17 deaths per million registered vehicle years, according to the study.

To read the full report, click here.