I have a 2017 CX-5. According to the owners manual, it has a 14.8-gallon fuel tank, when the fuel gauge nears empty (say 10-15 miles to go) it only takes 11.0-11.5 gallons.
I have slightly over 2000 miles on the odometer and have filled the tank 7
times. If I plot "Gallons Added to Tank" vs "Miles to Empty" it form a straight line
with a zero intercept of 11.7 gallons.
It may indeed be a 14.8 gallon tank, that is what it would take to fill the tank from a dry and empty tank, no baffle, no fuel pump or sender just a basic tank, you add the other stuff and the capacity drops, plus there is generally an error in the onboard computer calculations just due to the fact that every station is set different on where the fill nozzle shuts off and if your topping off the tank or not, so it's not straight forward on yes the tank will take this much fuel everytime it is refilled at this point on the fuel gauge, in real life if the fuel gauge says empty, is it really empty? No it's not it can have anywhere from a couple of pints to as much as a full gallon still inside, so don't concern yourself about capacity, you should watch the fuel mileage and never run it below the 1/4 mark, watching mileage can alert you to an engine problem and keeping the level above 1/4 keeps the fuel pump cool so it can last longer. HTH
While I understand completely that there might be as much as a gallon still in the tank when the tank registers "empty" in order to accommodate the fuel pump and sender, I did not expect nearly 3 gallons left. Mazda must be applying a huge factor of safety when they calculate miles to empty. Thank you for your response.
It's not like the old days when you could run it out of gas and put in a gallon to get you to a station and fill up, then you would know really close as to how much the tank actually held, but today doing that could cost you a fuel pump and the labor to put it in, not mention towing.
I have a 2017 Mazda CX-5 and have noticed the exact same issue. When filling the tank it tops out at around 11.7 gallons (with 10- 15 miles left on the computer). I called the service department today and couldn't get an explanation. I emailed Mazda today and will see if they have an answer. Very frustrating!
I heard back from Mazda. They indicated the car has 2-3 gallons remaining when the computer is at zero miles left. It's essentially a reserve. Check page 9-5 in manual.
Thank you Jan for the info. My 2017 Mazda CX-5 has the same issue and the service department has no idea why.
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