(MONEY Magazine) – A recent study by the Insurance Institute for Highway Safety (IIHS) examining the damage caused by sport utility vehicles and light trucks in accidents with other vehicles raises a big question for owners of those big vehicles: Will their insurance rates rise?

Specifically, the study included findings that could affect the liability portion of those rates. That's the part of your premium that you pay to cover damage you inflict on others in an accident. The IIHS report concludes that, on average, insurers have been paying higher liability claims for the largest SUVs ($107)--and even for small SUVs ($94)--than for passenger cars ($71). And experts say nothing drives liability rates up faster than insurers having to pay higher claims.

Even so, any widespread rate changes will take at least a year. Why? Because changing rates is a glacial process that requires insurers to present extensive research to state regulators, who then have to approve the rate hikes.

So far, two insurers have begun to charge higher premiums: Farmers Insurance Group and a smaller outfit called Progressive Corp. Farmers is doing so only in Pennsylvania and Maryland, where its premiums are now about 10% higher for SUVs like the Ford Explorer or Chevy Suburban. The insurer entered the market in the two states only recently, so it was setting its rates for the first time rather than going through the onerous process of changing them. "We researched what we were paying out in liability claims by make and model, and higher claims were incurred by SUVs and light trucks," says Farmers' spokeswoman Diane Tasaka.

Meanwhile, the study also found that in a collision involving an SUV and an automobile, occupants of the rolling family rooms are four times less likely to die than whoever is in the smaller car. So this could be the beginning of an unusual trend. Says Steve Goldstein, vice president of the Insurance Information Institute: "Charging a higher premium to drivers of safer vehicles would represent a sea change for the industry."

--James E. Reynolds