I have the 1998 brochure (2 actually). Both say 48 gallons...and I also see the 180 shows 37 gallons. When I fill the front tank, if I drive down a hill, gas comes right out the cap area! So at least it "seems" to be full. The previous owner swears he put 26 in both tanks several times. I think he said something like he would go 75 miles on one tank and then switch... Hey Lea, I appreciate the help, but don't hurt your head searching!!!