Originally Posted by TheOtherDave™

Total capacity for all the 94-01 Integra line is 13.2 gallons.
The dash light comes on when you've got about 3 gallons left.

You'll get a better estimate if you divide the number of miles between fillups by the exact quantity of gas consumed.

But it sounds like you do a lot of highway commuting. 340 into about 9 or 9.5 gallons is very good.