I just bought a new '05 XTerra on Saturday, had 150 miles on it at the lot, probably from test driving and such, and the dealer filled up the tank for me before I drove off the lot. Currently, I'm at 308 miles on the odometer, and I'm at half a tank. Probably not an accurate extrapolation from my first tank of gas, but right now I'm looking at around 310 miles per tank, give or take. Again, nothing technical here, just basing it on my first half a tank used. That was city driving, mostly back and forth to work, and my lunch hour.
Hope this helps a little

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