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Whats your average gas milage

Ultimate Gas Mileage Thread (Merged)

973K views 6K replies 759 participants last post by  NW07mazdaguy 
#1 ·
I am wondering...has anyone experienced poor gas mileage...taken
your 3 to a dealer because of it...and seen an improvement in your
mileage directly because of something the dealer was able to do
to your car?????  If so, could you PLEASE let us know what the dealer did.

OR...has a dealer tried different things to improve your mileage but failed to do so????  If so, PLEASE let us know what the dealer tried.

In other words-has any Mazda dealer in the world been able to "fix"
(especially the 2.3 Auto) the lousy gas mileage problem many of us
are experiencing?  Is it "fixable" by a dealer or are those of us unlucky enough to be getting poor mileage destined to have this problem for as long as we own the car.

Maybe there is a dealer here or there who has solved the problem.
And we can pass this info on to our dealer.  Or maybe it will turn out
that not even one Mazda3 owner has ever had the poor mileage
problem "fixed" by a dealer and that we are just wasting our time hoping that this or that might work.  Either way...it would sure be nice to know!

I am asking SPECIFICALLY if your dealer has been able to do something to your 3 to improve your mileage.  Or have they actually tried different things to improve your mileage that didn't work.  

I'm not asking about...mods to improve mileage, driving habits, oil
or gas, "try this's" or "try that's".  Hopefully this thread doesn't turn into a "I get good"-"I get bad mileage" pi***ng match.  Just, has your dealer been able to improve your mileage or have they tried something that didn't pan out?

I'll get the ball rolling.  My dealer replaced the FUEL PUMP (long crank problem) and hoped this might improve my mileage.  It has not!

Thanks for reading and hopefully participating.
everfeb
ps-my car is a year old, 7000 or so miles and broken in according to the book.  I had hoped over time my mileage would get better but it hasn't.
My patience has run out and I am only now  beginning to scream at my dealer about my mileage.
 
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#2 ·
Re: Gas Mileage Thread (Merged)

I know this isn't what you want to hear, but this is a trend in my 2.3 auto's milage that I've noticed and may be pertinent to solving your problem.

When I'm taking trips ~15-20 miles in length, or in traffic, or in the city, I observe ~20-23mpg no matter how easy or hard I am on the engine.

When taking trips 25+ miles in length, without traffic, on freeways, I observe 27-29mpg.

It's important for you to remember that the 2.3l engine in our car is tuned to perform as good as and sometimes better than your typical V6 found in most mid-sized sedans.

Here is what I think. I think the VVT technology is both a blessing and a curse depending on how far and where you drive. Stop and go driving is going to work the engine hard, especially with the VVT phasing in and out to add extra performance. This is compounded by our regular fuel ignition map and a restrictive airbox. Regular fuel burns fast when performance is being demanded of it. ---poor gas milage

But once you get the engine settled down on a long trip with cruise control set to ~70mph, the engine is doing little work and is running consistently and efficiently. ---good gas milage

What can a dealership do to solve the poor gas milage on the short trips? Advance the ignitions timing to work better with the VVT and unrestrict the airbox. I hope that's at least food for thought for the next time you bring this issue to your dealership.
 
#3 ·
Re: Gas Mileage Thread (Merged)

Unrecovery...thanks...I am not a techy guy AT ALL. Put gas in. Drive. Go to the dealer if there is a problem. So what is WT technology? I am though pretty interested in fuel economy and agree with your observations about how the 2.3 uses gas. Very poor around town only. Poor on short trip/town. And not too bad on long highway trips (for me if 60- 65mph).

Thanks for the food for thought, appreciate it.

everfeb
 
#4 ·
Re: Gas Mileage Thread (Merged)

It's VVT technology (two Vs), and it stands for Variable Valve Timing. Basically the engine adjusts it's valve timing for better efficency, there is a setting for lower RPM and higher RPM, I'm not sure if there are any in between. If your not looking for specifics, just know that it is Very Cool Stuff.
 
#5 ·
Re: Gas Mileage Thread (Merged)

VVT is Variable Valve Timing. The computer adjusts the cam timing while the car is running. It can get the best of all worlds, low end(RPM) power, mid range power, and high end power. In the old days, you put in a race car cam, and your car would have a lot of power at high RPMs but it wouldn't idle worth a darn, you put in a low end cam, and you would have good power at low RPMs but none at high RPMs. The VVT gives the engine much greater flexibility because it can vary between different camshaft timings. You probably won't notice it if you never rev the car up much.

everfeb: Dealers can rarely fix a gas mileage problem if there is nothing wrong. My grandpa had a similar problem with a Nissan Sentra from 1987. When he bought it, it would get 40+ mpg, something happened and the computer needed to be replaced and it only got 30 mpg. They changed everything and couldn't get the gas mileage back up, and he eventually just put up with the bad gas mileage. I know you don't want to hear it, but deffinitely try different brands and octanes of fuel (do 2 tanks of each in a row so you make sure most of the tank is the same type of fuel). I believe the 2.3 with the auto just gets bad gas mileage. Even Consumer reports got between 18 and 38 with the 2.0 litre with the Auto, average 27, and that does better than the 2.3. Look at your window sticker, and in the fine print below the EPA rating, it says what actual mileage ranges for this car (not the similar car secion) should be. The EPA is a specific rating cycle that a lot of people won't be able to acheive, but a lot of people will also get better than the EPA rating. This range shows what you should expect. Also, don't let your car idle to warm up for more than 1 minute or so, that will really waste gas, especially for short trips.
 
#6 ·
Re: Gas Mileage Thread (Merged)

I didn't know this up until recently but the A/C stays on (even if you have the button in the off position) when the heater is on and the direction is in the floor mode on the dial. If you keep the direction in the vent/floor position on the dial the the A/C will stay off.. This could account for some very bad gas mileage when you don't expect it in the winter time..
 
#7 ·
Re: Gas Mileage Thread (Merged)

By gum he's right!

Pg. 6-7
• In the [floor] position, air conditioning
is automatically turned on to defrost
the windshield (however, the
indicator light does not illuminate)
and the position [outside air] is
automatically selected.

Also pg. 6-8
• In the [defroster] or [defroster/floor] position, air
conditioning is automatically turned
on to defrost the windshield quickly
(however, the indicator light does
not illuminate) and the
position [outside air] is automatically selected.
The air intake selector switch
cannot be changed to the [recirculate]
position.
 
#8 ·
Re: Gas Mileage Thread (Merged)

Tony said:
I didn't know this up until recently but the A/C stays on (even if you have the button in the off position) when the heater is on and the direction is in the floor mode on the dial. If you keep the direction in the vent/floor position on the dial the the A/C will stay off.. This could account for some very bad gas mileage when you don't expect it in the winter time..
I've been getting ~26 mpg, doing mostly around town/stop & go type driving. I've had the heater set to floor just about all the time (until now). I guess I should see an increase in mpg.

One thing to keep in mind; the compressor cuts out below 32F. Also I'm pretty sure that when the fan switch is "OFF", then the compressor is kept off.
 
#10 ·
Re: Gas Mileage Thread (Merged)

Tony said:
I didn't know this up until recently but the A/C stays on (even if you have the button in the off position) when the heater is on and the direction is in the floor mode on the dial. If you keep the direction in the vent/floor position on the dial the the A/C will stay off.. This could account for some very bad gas mileage when you don't expect it in the winter time..
What, you mean to tell me that I've contributed to the low gas mileage b/c I've been leaving the airflow on the "floor-only" setting?!

Thanks for the info, I'm going to set it to vent/floor and will let ya'll know how things go after a couple gas fill-ups. Currently, with "floor only" setting, I get a smidge over 22 miles a gallon.
 
#11 ·
Re: Gas Mileage Thread (Merged)

Vent/floor also runs the compressor.
 
#12 ·
Re: Gas Mileage Thread (Merged)

If mode selector dial is set at "floor" or ANY other setting to the right the A/C compressor comes on- regardless of whether the A/C button is pushed or not-if fan speed is 1 or higher. It doesn't matter where your temp contol is set...hot or cold...A/C is on. At 32F my A/C compressor still comes on. At 23F my compressor does not come on...it just does not come on regardless of mode setting or if the A/C button is pushed or not. So in 23F or colder weather, the A/C is not on even in "floor">"defrost" settings.
In any setting to the left of "floor" the A/C compressor comes on only when the A/C button is pushed except in colder weather when A/C does not come on no matter what.

I'm KIND OF SURPRISED at the response to this thread. 867 VIEWS so far and apparently not even one person has taken their 3 to a dealer to have their poor gas mileage problem checked out???
Strange considering so many people post about it, especially owners of the 2.3 AUTO.

BTW..blsgtr...26mpg mostly around town with 2.3 AUTO is excellent. Leave your floor heater on!!! On 61%Hwy/39%City miles driven I've averaged 22.4 mpg. Shoot...if I drive over 70mph I don't come close to getting on the highway what you get around town!!!!

Brian_B...pretty good...at least you're around EPA which is unusual...my mileage is 20% worse than the EPA #'s which is why I started this thread hoping someone might have had poor gas mileage fixed by something a dealer might have done.
everfeb
 
#13 ·
Re: Gas Mileage Thread (Merged)

RonH said:
Vent/floor also runs the compressor.
Ron, I just checked on my car, and the compressor cycles when the switch is set to "floor" (A/C button-off), as we now know.

When I turned the switch 1 click to the left (~11:00 o'clock), I didn't see the compressor clutch pull in at all. So this tells me that at least the first "in between" position of vent/floor doesn't call for the compressor.

Wacky climate controls!
 
#15 ·
Re: Gas Mileage Thread (Merged)

I think it's wierd that the A/C comes on with the floor only setting; according to the manual this allows for window defrosting. Doesn't this make the defrost & floor setting redundant? Everything from the center to the right of the dial uses A/C which I can verify with the smell test. The car's performance improved a bit on today's commute. I was still getting over 22mpg in overall driving with my defroster always on before.
 
#16 ·
Re: Gas Mileage Thread (Merged)

Wait a minute, when I don't need to use the AC, heat, or defrost, I leave the fan knob off, and the other knob set to defrost. Are you trying to tell me that in these settings, the AC compressor or anything involved with this system is ON? I really doubt that, that seems impossible and not the way Mazda made it to work. Plus, when NOT using the AC, Heat or Defrost, how could that part of the car affect gas mileage if nothing is running?

In my last 2 tanks I've only been getting 21 & 22 mpg. I'm going to change my commute so that I'm driving more highway miles than local roads and slow speeds, I'm hoping this will increase my miles per gallon as I have heard it's proven that more highway miles in a tank of gas gets better MPG no matter what!
 
#17 ·
Re: Gas Mileage Thread (Merged)

Mello...maybe we can get "blsgtr" to do his thing with the compressor clutch and see if with fan in off and mode selector dial in "defrost" anything happens. I kind of think when the fan is off the whole system is off but you never know with HVAC.
Can you help "BLSGTR"??
BLSGTR...another question. You did your compressor clutch thing with car idling. In your opinion would the A/C compressor operate the same at highway speeds as when idling? Thanks
everfeb
 
#18 ·
Re: Gas Mileage Thread (Merged)

Something I've noticed... with my car in anything other than the left most setting on the A/C... i hear the compressor kick in. Havent paid attention if it does it with the fan in off position but it DOES do it in floor/vent mode with fan speed at 1.
 
#19 ·
Re: Gas Mileage Thread (Merged)

Tony said:
I didn't know this up until recently but the A/C stays on (even if you have the button in the off position) when the heater is on and the direction is in the floor mode on the dial. If you keep the direction in the vent/floor position on the dial the the A/C will stay off.. This could account for some very bad gas mileage when you don't expect it in the winter time..
OMG.
 
#20 ·
Re: Gas Mileage Thread (Merged)

I just wanted to pop in and say I totally agree with Unrecovery.

I've noticed the same issue and I'm currently trying to adjust my low mileage trips for best efficiancy. I suspect if you keep your shift points high you'll get better mileage, the torque "pull" at low RPMs is the gas eater.
 
#22 ·
Re: Gas Mileage Thread (Merged)

there are 2 reasons to turn the A/C compressor on during defrost.

1. to help keep the air dryer and moisture free. moisture in the air is what starts fogging up the windows.

2. it keeps the compressor oiled. imagine if your compressor never got oiled for 6 months out of the year. then all of a sudden you were running it full blast. it wouldnt take more than a couple years to sieze that puppy.
 
#24 ·
Re: Gas Mileage Thread (Merged)

MetalCord...If you read my original post you can see that-on this thread-I was hoping to get replies SPECIFICALLY from people whose poor mileage either WAS improved by something a dealer did to their 3 or whose poor mileage WAS NOT improved by a dealer. Very specific. Has a DEALER out there actually been able to do something to a 3 to improve it's mileage OR have the things dealers have actually done to try to improve poor mileage not worked and wasted their and their customer's time. I was actually trying to avoid a "How can I improve my mileage" topic.

Now, with 1234 views, there has not been one response which directly answers my questions. Lots of helpful replies which I appreciate but none which answer my question. At this stage I'm starting to think that not even one person has taken their 3 to a dealer to see if the DEALER can do something to improve poor mileage. And this surprises me with so many people (maybe we are the vocal minority) complaining about mileage.

Anyway, there are many many ways we ourselves can try to improve our mileage on our own so it IS a real good idea to start another topic based on your suggested titles (above). Go for it. I would be interested in seeing what people have to say and it WOULD BE NICE to see all the different ways people try to improve their mileage..located under one topic.

everfeb
 
#25 ·
Re: Gas Mileage Thread (Merged)

everfeb said:
Mello...maybe we can get "blsgtr" to do his thing with the compressor clutch and see if with fan in off and mode selector dial in "defrost" anything happens. I kind of think when the fan is off the whole system is off but you never know with HVAC.
Can you help "BLSGTR"??
BLSGTR...another question. You did your compressor clutch thing with car idling. In your opinion would the A/C compressor operate the same at highway speeds as when idling? Thanks
everfeb
I would guess that the cycling rate of the compressor would be determined by rate of heat transfer in the plenum core. When the pressure switch(es) are closed, the compressor clutch is pulled in. The in (on) cycles are fewer and farther between as it gets colder. On a 35 degree day, there probably shouldn't be too much mpg loss.
 
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