I have a 97 honda civic ex coupe with 165xxx. the fuel light comes on at a relitive rpm. so if you are going 60 mph, 2250rpm approx, you have a minimum of 30 miles. i just ran my car to .01 gal left in the tank, according to the gas pump. i ran over 40 miles with the light on at 65mph. so if it comes on just set the trip and you have on average 30 miles to fill up.