Hey everyone,

I am new to this forum. So I apologize in advance if this shouldn't belong here, or if this has been asked already. I tried searching for it on this forum, but couldn't find anything.

So, this has been bothering me for a while now .

Mazda 6 2015 tank size is supposed to be 16.4 Gallons ~ 62L.

When I am driving my car reaches approximately (depending on my driving ) 400 miles. usually I refill my gas when the display is telling me that I have only 5 miles left. So if I passed 400 miles with 16.4 gallon that's aprox. 24.4 miles per gallon.

But then when I gas up my car I always gas up about 12 gallons max and it reaches the full tank capacity. WHY ? Is that part of some reserve gas protection ?

 

I am interested to hear what others have to say...

I have a 2015 Mazda 3 and have the same problem. I can only put 10 gallons in the 13.2 gallon tank when the tank is nearly empty. My question from day 1 is: Is there 3 gallons of air in the tank when full or 3 gallons of gas when empty?

While I understand you should not drive your vehicle until empty due to contaminants getting into the fuel filter, 10 gallons of gas for me is not enough to make it from Monday to Friday and is often not enough to make it through the weekend.

Hopefully the brilliant engineers at Mazda have designed the warning light to force us to leave 3 gallons in the tank avoiding the fuel filter problem.

 

Hey,

Thanks for replying. I was thinking the same. That it could be some kind of protection, but 4-5 gallons is a lot. It just seems kinda strange.

 

And to your first point. Welcome to the forum. Please don't be afraid to ask anything. If someone thinks it is an easy question, they don't have to respond. This leaves the door open for those of us with less technical knowledge to contribute. If people only ask the most complex questions, people like me would have nothing to contribute, I would also have little interest in the forum since I tend to rely on a trusted mechanic for the maintenance and repairs, although my Mazdas have needed few repairs so far.

 

I'm going to say it's probably reserve. On many of the cars I've had, I could drive for miles and miles when it says "0" miles left. I've pushed our Pilot close to 30 miles on "0" and my Passat above 40 driving through the Adirondacks in the middle of the night when I couldn't find a station (scary). I can leave my house in my current Mazda6 at 0 and drive to work 16 miles away without issue.... I know... not good to go this low. Gas prices are cheaper near where I work, so sometimes I push it.

 

In my experience, there is no such a thing as a modern car on the road today which is out of fuel when the DTE (Distance To Empty) display shows zero, in fact, many cars, my TL for example, can drive over 100 miles after the DTE shows zero and still not run out of gas.

Just a fact of life.

 

I passed the question on to Mazda. They told me that the tank has 2 to 2.5 gallons in the tank when it reaches zero miles remaining. This is to give you enough gas to make it to a fuel station and so that you don't use the gas at the bottom of the tank and risk damage to the fuel pump. My frustration with this is if we are buying gas when it has 75 miles or so remaining (to keep 2.5 gallons in reserve) and Mazda has adjusted the computer to keep 2.5 gallons in reserve, we end up with 5 gallons in reserve. As a result, we end up making roughly 1/3 more fueling stops than we need.

 

Then there are cars like my TL where the DTE shows zero when only 13 gallons of the published 17 gallon capacity has been used; of course that four gallons is in addition to the two and a half reserve; very annoying.