My 2009 Mazda6 2.5 has 11-15 mpg city. Should I worry?

[waterbuck1]

Hi-
I have a 6-week old Mazda6 2.5 liter automatic tranny, with about 1500 miles on it. It drives just fine.

my average mileage, as registered on the trip computer during a period of mostly in-town driving (birmingham, al) , is generally 11-14 mpg.

An average with mixed city and highway was about 18 mpg.

My first manual calculation based on miles since last fill-up suggested an average of 15 mpg. I need to confirm that by doing it a second time.

I don't run the rpm's high, and sometimes I use manumatic shifting to try to improve mileage as well. The car runs well.

City mpg of 12-14 mpg is lower than the epa estimate of 20mpg.

Is this something that needs to get checked out? Since the car drives perfectly, I don't even know what to ask the dealer to look at.

 

[zinger002]

wow, thats not great. one would assume that the car would still need to be broken in a bit more for some bigger conclusions to be drawn... but it wouldnt hurt to see if its warentied...

 

[coyfish]

Yeah thats not normal. Thats about all I can do to help you sry. . .

 

[niky]

EPA estimates don't take into account how you drive and what weather you drive in...

The best way to figure out if there's anything wrong with your car is to fill her up to the first click on the pump's auto-shut-off, run on the highway (preferably on a weekend with light traffic) at about 60 mph for an hour or two, go back to the same station and the same pump and fill up again. If you can't get within 5 mpg of your car's EPA highway figure, then something might be wrong.

Of course, consider also that your car's engine is still "green" and has to be broken in properly... you might want to wait another 2000-3000 miles before doing this test.

 

[tunersteve]

Moved to correct section.

 

[Blendercloud]

I don't know the solution to your mileage problem. However, I have had a couple of experiences with relatives where they had a similar problem. They returned the car and the dealer replaced the engine once and in the other instance replaced the entire truck.

I would go to the dealer right away to report your problem and have them look over it. If they cannot find anything, you should consider changing where you fill up. If over the next 1,000 miles it still does not improve you should speak to that dealer again. The car is obviously not performing as advertised.

 

[Trip CX90]

Few misc thoughts . . .

I've had my 09 6 for about 3 months now. 7,000 miles. It's a 2.5L 6MT. I started off with an avg city/hwy of 24/30. It's now around 27/32. But I do a lot of "rural" and suburban driving. Only about 10% stop and go city driving.

Most newer engines are built with tight tolerances. A break in period for max power or fuel economy is a must. As others mentioned, driving style and weather can affect fuel economy. Your location can as well. Gasolines with higher ethanol levels tend to burn cleaner but are worse on fuel economy.

Check your tire pressures! Tire pressures can affect fuel economy. I keep mine 2 - 3 psi over factory spec.

Try switching to a Top Tier gasoline to see if it helps. www.toptiergas.com

For poops and giggles, try a fuel system cleaner. When you're below 1/2 tank, dump a can or two in, and fill up.

Does the transmission feel like it's shifting properly? Not slipping or harsh? Does it drop revs when cruising?

If the transmission has a "sport shift" feature? Try to drive with it for a full tank and be sure to shift it early to keep revs down.

An off the wall thought . . . Do you know how old your car is? Even tho I recently purchased, my car was close to a year old. If your car was sitting around on a lot for awhile, check all the fluids to make sure they're at proper levels and clean. Check the air filter, too. It's not uncommon for critters to stop it up.

With these fairly easy measures you might rule out a few things. If something is dirty/clogged up, the car is responding with richer fuel mixtures to compensate. The other possibility is that it is a hardware problem. A sensor is sending the engine mgmt computer bad info. On that note it could be a software problem, too.

Lastly, you have to consider that maybe it is what it is. Even tho engines are built to the same specs, inexplicably, they can vary from each other. It's possible the tolerances in your particular engine add up to so-so fuel economy. As long as it performs well otherwise, it's probably nothing to worry about if some preemptive measures turn up nothing.

 

[mitchflorida]

My guess is that you are not improving your gas mileage buy using the manumatic feature. Probably the opposite. The automatic transmission has a computer that calculates the best shifting patterns for gasoline mileage, and your constant shifting probably interferes with that.

I would only use the manumatic when you want to increase performance or acceleration at the expense of gas mileage.

 

[niky]

How long are your trips, and how much traffic do you drive in? Excessively short trips can increase consumption... a lot.

I've actually seen that range of economy from the 2.5 liter engine, but only when using it for short trips (say, five miles or so) in traffic. Hell... I can get 11 mpg in traffic from my Protege 2.0. Of course, that's because my cams are so honking huge.

Again, the only way to know for sure is to take it on a good, long, highway cruise away from traffic, with a top-off to top-off fuel reading.