Comparing auto insurance for an SUV vs. auto insurance for a truck is largely meaningless. That's because there are differences in the price of different models of each kind of vehicle and there are other factors that influence insurance costs. However, you can get a general understanding of insurance costs for the two kinds of truck by looking at a few points.
The Myth of Models
One pervasive myth in the insurance world is that particular kinds of cars, such as SUVs or sports cars, cost more to insure because they encourage dangerous or expensive driving. This is not true. Insurance companies base their prices on analyzed risk and the statistical data behind it -- not on notions of the drivers who buy certain kinds of cars.
Cost of the Vehicle
One place the SUV vs. truck factor might affect insurance rates in a meaningful way is the cost of the vehicle in question. Insurance rates are based in large part on the value of the vehicle being insured. In general, an SUV is a more expensive vehicle than a truck of a similar class made in the same year. There are, of course, exceptions: a new truck might be more expensive than a 10-year-old SUV and thus cost more to insure.
Vehicles with advanced safety features such as traction control, side curtain airbags and proximity alerts can qualify for insurance discounts. Since SUVs are considered family vehicles, some models come standard with safety features a truck in the same class does not. This can mean reduced insurance costs for the SUV.
Your insurance rates will vary according to the make and model of the vehicle, your driving record, the ZIP code where you park, market rates, your age and marital status and even your credit rating. Although a national "average" insurance number is meaningless in context, it's true that SUVs are generally more expensive than trucks -- meaning that, on average, somebody with both an SUV and a truck would pay less to insure the truck assuming the two were of similar classes and built the same year.