Volcanic rocks often have a vesicular texture caused by voids left by volatiles trapped in the molten lava. Pumice is a highly vesicular rock produced in explosive volcanic eruptions.
The Dodge Nitro is available as a sport utility. Inventory prices for the 2011 Nitro range from $6,585 to $16,609. It gets EPA-estimated 18-19 MPG combined.
The latest price cut actually puts the 2015 on par with the original 1992 Viper when adjusting for inflation. Those first models carried a cost of $50,700 when new or about $86,130 today, according to Dodge. The 2015 Viper is getting mechanical updates too with all models upgraded to 645 horsepower and a highway fuel economy rating of 20 miles per gallon, a 1-mpg improvement.