I been using a 99 npr. 5.7 220-180 miles on usually 100-120. In gas at 3.20-3.59 gal. Its enclosed its locked nobone knows the wiser. Plus side can fit couple hundred pcs in it. Or 6-10k lbs of batteries lol either way she does her job ohh my luck is its only cpsted 5-10 cents per mile for maintinence 6-7k$ in 180k miles.