Hello,

My son just bought a 2017 Mazda CX-5 Grand Touring. The car had only 10,000 miles on it and it is almost like new. We were looking at the gauges on the car as it relates to Fuel mileage and Distance to Empty (DTE). The car's gas tank is suppose to hold 14.8 gallons but with the fuel pump and other things is will probably hold less. The issue is when he fills up his tank, and he does not try to overfill, the actual Full to Empty Gauge shows Full, yet the Distance to Empty (DTE) shows only 266 miles on a tank when it should be showing 400+ miles available per tank fill. Is this a problem with the cluster? The car is under warranty for 12 months or 12,000 miles. Every time he fills the tank the DTE says 266 miles.

I told him to just use the F to E gauge and to fill up when it hits 1/4 of a tank and to ignore the DTE reading as he needs to make sure the fuel pump is covered adequately. He has tried resetting the MPG averages but it still shows 266 miles for a full tank.

Anyone else have these issues?

If so what was the solution. Should he disconnect the Battery and see if it will reset?

Any advice would be appreciated.

Thanks In Advance

 

The DTE readout will vary its reading based upon previous driving style and previous gas mileage. You can often see it adjusting if you watch it closely, but I would recommend keeping eyes on the road. If my wife drives the CX5, it will predict about 290 to 300 miles when the tank is filled. If I have driven it primarily for a while, it will often show about 360. My wife has a heavy foot.

 

The DTE is based on historic data. Clearly the previous driver did short infrequent trips, resulting in poor fuel economy & calculated DTE for fuel.

Disconnect the battery over night. Reconnect and drive normally. This should reset the learning process.

Also reset the trip meters (A&B) plus the fuel economy average data everytime its filled with fuel.

 

Mine was higher then I would ever get when I filled up. After a few tanks, the great distance to empty adjusted to closer to what I was actually getting. It is still more optimistic when full. I don’t look at it until it gets low.

I had the similar question from a different perspective. In addition to the miles per tank issue, I focused on the fact that I could only put 10 gallons of gas in a tank that had a capacity of 13 in my Mazda3.

I called Mazda and asked them the question: is there 3 gallons of gas in the tank when the remaining miles is zero or is there 3 gallons of air when I fill it up?

They said the computer hits zero with extra gas to leave you with fuel to get to a station if you drove to zero plus the reserve to protect the fuel pump.

Basically, I was leaving a quarter tank to protect the fuel pump and Mazda was leaving a quarter tank meaning I had nearly a half tank in reserve. I now buy gas before the light comes on but not by much.

 

The fuel pump is required to be submerged in fuel to prevent itself from overheating and premature failure.