A new study attempting to quantify motorists' vulnerability to higher gasoline prices shows Hawai'i drivers aren't that bad off compared to many other states.

The report by the Natural Resources Defense Council, a non-profit group that says it's dedicated to protecting public health and the environment, found Hawai'i drivers spent 4.58 percent of their income on gasoline.

That ranked 40th; the state with the worst vulnerability was Mississippi at 7.87 percent.

"This report shows that when oil prices go up, families in some states are hit much harder than others because they are paying a greater percentage of their income at the gas pump," said Deron Lovaas, one of the report authors.

While the report attempts to rank states and the threat rising oil prices pose to them, it doesn't take into account Hawai'i's use of petroleum for much of its electrical generation. On this basis, Hawai'i's economy is said to be the most fragile when it comes to rising oil prices.

The U.S. Energy Information Administration says Hawai'i relies on oil for about 90 percent of its energy needs.

Lovaas said he and other analysts had looked at how much motorists in each state drive daily, the fuel efficiency of their vehicles and compared that against personal income in coming up with the ranking.

Lovaas said it appears Hawai'i is in a very difficult situation when told of the dependence on oil for producing electricity here.

Lovaas also looked at solution rankings for each state, examining public policy responses such as offering incentives for purchases of hybrid vehicles. In this respect, Hawai'i ranked 32nd, with the top state being California.