With the Prius fuel tank capacity of 11.9, that means I have 2 gallons left in the tank. For this fill-up, I have driven the Prius 20 miles past zero on the cruising range meter (aka miles to empty). The Prius manual states that when the last fuel bar begins to blink, there is approximately 1.6 gallons or less left in the tank (p. 498 of the Owner’s Manual). I find the official value of 1.6 gallons remaining as soon as the low fuel indicator begins to sound and blink inconsistent with real world data. After tracking this number a couple of times in the past, the accurate gallons remaining is a staggering 1.9 to 2 gallons. So once the low fuel indicator starts blinking, you have between 80-120 miles left of driving range, depending on ambient temperature (extreme weather affects MPG negatively) and driving conditions (consistent uphill driving and stop & go traffic also kills MPG), before the tank goes dry.
My gas expenditure used to be anywhere from once every two to three weeks to once a week (due to excessive road trips) to now once every five to seven weeks. However, because of the shorter commute and colder winter climate these days, the MPG has decreased dramatically. I may need to look into grill blocking strategy to kick the MPG up a notch and jump back into the 50+ MPG arena. Still, spending between $35-$45 on gas once every 1.5 to 2 months is not a bad deal compared to $200-$250 a month with the RSX. Depending on how often we take my Prius on road trips instead of the lady’s Prius C, gassing up 7-12 times for the entire year is not too far from reality. If I had the Plug-in Prius (which I regret not getting instead), I’d probably run on 100% EV mode all day everyday. At approximately $2.00 a charge, it would’ve cost me only $16.00 a month for charging. As it is, the total cost of owning my Prius (since it’s already paid off), is about $82 a month, factoring gas and insurance.