Fuel Economy

[kk3]

ive been reading through most of the forums and have dont think that anyone has as bad a fuel economy rating as mine.

i have a 2005 gt 2.3 auto
i usually let the trans shift at about 2.5k to 3.5k
so im not really racing it
my city rating is horrible..
im getting avg 12-14 L/100km
so that means a tank averages only a few hundred kilometers.
no where near the 500-650ish km other ppl are getting..

high way i get about 10 l / 100 km
its not bad but i drive fast.
for some strange reason when i drive at common speed or the limit
100 - 120kph (3000ish rpm), i get even worst milage than when im
doing 140ish ( 4400ish rpm)
has any one experienced this?

and what can i do about such bad milage.??
i love my car and i want to keep it for a long time.
but with gas being so expensive and the economy rating for a truck (new tacoma 4.0 v6 similar to my rating) i really dont want this problem to continue.

[PiCASSO]

Originally posted by everfeb


PICASSO...yup, misery loves company. Question...when they did the diagnostic with the sensors and computer did they just hook it up and scan it or/and did they download the latest update and reflash the PCM?? I hope I\'m using the right terminology???
everfeb

Hmmm... not sure exactly what they (Avante Mazda, Richmond Hill) did with my Mazda. I would assume that if the firmware on the PCM was dated, they would upload it accordingly. I tried to ask questions like, \"was my car operating on the low or high end of the specification\", but I got no answer from the assistant service manager. Either he didn\'t know, or simply isn\'t used to an engineer asking technical questions regarding the work done on a vehicle. I\'ll follow up with them the next time I have an oil change done and verify that all the software (firmware) on the PCM is up to date.

[kl7402001]

holly cow!! 17L/100km?? ... man mine is pretty good .. 10L/100km ...

Shift at earlier rpm range man ... and i think this helps alot .. watch out for the blinking hand .. thats signalling a yellow coming soon so let off the gas .. or speed up .. so u won\'t have to stop and lose gas on stop and go ..

[keving]

Got the spreadsheet, thanks PiCASSO.

Kevin

[everfeb]

Originally posted by kl7402001


holly cow!! 17L/100km?? ... man mine is pretty good .. 10L/100km ...

Shift at earlier rpm range man ... and i think this helps alot .. watch out for the blinking hand .. thats signalling a yellow coming soon so let off the gas .. or speed up .. so u won\'t have to stop and lose gas on stop and go ..

Thanks for the tips. I already do these and everything else I can think of to get optimum gas mileage. Rolling stops, no more than 30 seconds idle at initial startup, turn motor off if I figure I am going to be sitting for longer than 10 seconds (not in traffic of course but for example a drive through window)..tire pressure..avoiding turning A/C by not using \"floor\" to \"defrost\" settings.

It\'s not the way I drive...it\'s the car...I really think there is something very wrong with it...for such a small car with such a small motor my 2.3 auto is a real gas pig when it comes to city driving. It\'s no hell at speeds above 65mph/105kmh either. Just something wrong.

The service department where I bought my 3 is really not up to speed so I\'m done with them and will be going to another dealer. Hopefully, they\'ll be better problem solvers???
everfeb

[kl7402001]

maybe ur O2 sensor is busted .. so ur car don\'t know how rich u are running? ..oh man hope u find the problem ...

[PiCASSO]

Originally posted by kl7402001


maybe ur O2 sensor is busted .. so ur car don\'t know how rich u are running? ..oh man hope u find the problem ...

Yeah, that\'s something that my dealership (Avante) did is measure the O2 (Oxygen) levels before and and after the catalytic converter, and (if I\'m not mistaken) before the intake to see if the vehicle was running rich or lean. But \"everything was within normal parameters\" as mentioned by the service department. Oh well...

[everfeb]

About the O2 sensor I read somewhere there was a problem with California cars...the sensor was reversed somehow or other (I think). MAYBE some of our O2 sensors could be buggered...you never know.
A poster from Calgary on the Mazda Axella 3 forum was getting poor mileage and her dealership has replaced the \"emission harness\" and \"air flow sensor\" and said this should improve her mileage. She\'s checking a tank of gas now to see if mpg improve and is going to report back. Anyway I have no idea what this \"harness\" and \"sensor\" are. Maybe someone could enlighten? I will mention these 2 things + 02 sensor to my NEW service guys and see if they can determine anything.

PiCASSO...sounds like your dealer cares?? And is at least trying. Hopefully my NEW one will too.
KL7...Thanks..I do to. I have been very patient hoping my mpg would kind of improve over time on it\'s own. So I haven\'t done a lot of complaining to dealer. But mpg is getting worse so it\'s time. The service dep\'t at dealer where I bot the 3 just didn\'t seem to know anything or much care which is why I\'m leaving them. Hopefully the service people at the dealer I\'m going to be going to will be sharper and more up to speed.
everfeb

[everfeb]

KEVING...have you complained to dealer at all?? Have they tried anything to improve mpg?
According to brochure 9.2L/100km is the ultimate goal for city driving with your 2.3 5spd however these numbers are pretty much unattainable when a car is driven normally...especially in cold weather. But bring it to their attention if you haven\'t already. Maybe if enough of us who ARE AWARE of the fact we are getting poor mileage start to complain- Mazda might pay attention. I feel this car was sold to me very much under false pretenses as I get no where near the advertised mpg.
BTW..I do like the car. Just want to be able to drive it further for my money!!

everfeb

[PiCASSO]

Originally posted by everfeb


About the O2 sensor I read somewhere there was a problem with California cars...the sensor was reversed somehow or other (I think). MAYBE some of our O2 sensors could be buggered...you never know.
A poster from Calgary on the Mazda Axella 3 forum was getting poor mileage and her dealership has replaced the \"emission harness\" and \"air flow sensor\" and said this should improve her mileage. She\'s checking a tank of gas now to see if mpg improve and is going to report back. Anyway I have no idea what this \"harness\" and \"sensor\" are. Maybe someone could enlighten? I will mention these 2 things + 02 sensor to my NEW service guys and see if they can determine anything.

As far as I understand, the \"emission harness\" is electrical wiring that connects the \"air flow sensor\" (up front at the intake manifold) and the two O2 sensors (behind the exhaust manifold, between the catalytic converter), which make their way to the ECM (engine control module) that will determine if the amount of air input is equivalent to the air output designed by the software program on the ECM. The ECM has a specific emission program for a specific region. You\'ve probably heard \"California emissions\" on The Price is Right, which has a unique tail pipe emission requirement compared to the remainder of the 49-states. I believe that Canada adopts the US 49-state requirements. Europe has also different requirements, where they are now at Euro4 emissions, which through each revision has become more and more stringent. I used to work at DCX for 3-years (3-years ago) so I\'m trying to recollect a little of what I did with homologation.

Originally posted by everfeb

PiCASSO...sounds like your dealer cares?? And is at least trying. Hopefully my NEW one will too.

My dealer cares probably because I\'ve put a complete matrix showing all the various figures on my fuel economy on the Mazda3. I guess that they know that I\'m a little educated and therefore can\'t bullsh*t me around. Regardless, I still think that Avante Mazda provide great service... (I\'ve brought her in twice so far). Best of luck with yours. If you need the emissions matrix that I gave to Kevin... I\'ve attached to this post the Excel file, which I\'ve renamed the extension from *.XLS to *.DOC. If you can\'t see the extension... simply change the settings in your Windows Explorer under: TOOLS -> FOLDER OPTIONS -> VIEW -> uncheck the HIDE EXTENSION FOR KNOWN FILES -> APPLY.

Cheers,

PICASSO

[keving]

everfeb,

Thanks for the advice, I will probably ask my dealership (avante richmond hill) what the problem is soon. However, I only have 4500 km on my car so far, so *perhaps* my car still hasn\'t full broken in yet. But I will definately bring it to Avante R.Hill\'s attention that another mazda3 owner isn\'t happy with the fuel economy.

Kevin

[PiCASSO]

Latest Figure:

February 5th through 11th
90% city driving, 10% highway
224.8 km
25.380 L
11.290 L/100km (20.834 MPG)

Not getting any better... with approximately 9,000 km on the clock.

[majic]

now for some latest results

2005 | Jan | 1 | 44.35 | 4342 | 503 | 8.82 | 26.68 | Esso | 0.699 | 31.00
2005 | Jan | 6 | 48.717 | 4865 | 523 | 9.31 | 25.25 | Shell | 0.739 | 36.00
2005 | Jan | 7 | 39.189 | 5385 | 520 | 7.54 | 31.21 | Esso | 0.689 | 27.00
2005 | Jan | 10 | 38.625 | 5799 | 414 | 9.33 | 25.21 | Sunoco | 0.699 | 27.00
2005 | Jan | 15 | 49.394 | 6340 | 541 | 9.13 | 25.76 | Esso | 0.689 | 34.03
2005 | Jan | 25 | 45.9 | 6793 | 453 | 10.13 | 23.21 | Esso | 0.719 | 33.00
2005 | Jan | 29 | 46.15 | 7234 | 441 | 10.46 | 22.48 | Sunoco | 0.715 | 33.00
2005 | Feb | 5 | 46.009 | 7682 | 448 | 10.27 | 22.90 | Esso | 0.739 | 34.00
1. 2005 | Feb | 11 | 45.855 | 8199 | 517 | 8.87 | 26.52 | Shell | 0.807 | 37.00
2. 2005 | Feb | 12 | 47.623 | 8813 | 614 | 7.76 | 30.33 | Esso | 0.819 | 39.00
3. 2005 | Feb | 13 | 49.42 | 9417 | 604 | 8.18 | 28.75 | Shell | 0.769 | 38.00

last 3 lines is my trip to montreal, treamblant and about the town (and back to TO)

1. some city but mainly highway a few traffic jams (sporadic) but pretty good avg for some mixed driving

2. did about 100km around town here (not too much stop and go) and then on the hwy to mtrl i drove @ 110kph half way and then when i relized we\'re running late for our reservation is stepped it up to 117-119kph (cruise)

3. ALL but about 20km (at most) highway, 20km was pretty much downtown mtrl in traffic going places. cruise @ 117-119kph


looks like 110kph cruise is a very favourable speed. 7.54L/100km was done going at about 100 on major hwys and 92-94kph in 80 zone

[kl7402001]

new update ... normal driving .. this fill up 41L and 463km ... 8.85L/100km

[majic]

Originally posted by kl7402001


new update ... normal driving .. this fill up 41L and 463km ... 8.85L/100km

normal is subjective.. my normal might be different from yours - and probably is. so if you\'re not gonna post at least highway/city, then the figures are meaningless arc

[PiCASSO]

Originally posted by majic

Originally posted by kl7402001


new update ... normal driving .. this fill up 41L and 463km ... 8.85L/100km

normal is subjective.. my normal might be different from yours - and probably is. so if you\'re not gonna post at least highway/city, then the figures are meaningless arc

Agreed. I would recommend that people provide:

1. Approximate percentage of City Driving (anything under 80km/h)
2. Approximate percentage of Highway Driving (anything over 80km/h)
3. Approximate RPM shifting range (3,000 RPM, 4,000 RPM, etc)

And if you want to be specific, you get get into the details on average speed on the highway, even the city driving (stop/go), etc. Something to think about.

[everfeb]

AGREED....AND what you are driving. A 2.0L 5spd is supposed to get much better mileage than a 2.3auto. If we don\'t know what you are driving we really can\'t tell if you are getting good or poor mileage.
everfeb

[Indusbreed]

I am averaging at 590-600KM per tank if do hwy driving. 560-580 for city driving.
I have GS 2005 2.0L Auto. I have 1600 Kms so far on the ODO.

[PiCASSO]

Originally posted by Indusbreed


I am averaging at 590-600KM per tank if do hwy driving. 560-580 for city driving.
I have GS 2005 2.0L Auto. I have 1600 Kms so far on the ODO.

How much is a tank? 55 liters (giving you from 9.17 to 9.82L/100km) or perhaps 45 litres (giving you 7.50 to 8.04 L/100km)??? Honestly... a spread of 7.50 to 9.82L/100km is a lot. You need to determine how much fuel you are filling up each time you go to the gas station.

[Indusbreed]

Tank is 55L.

[PiCASSO]

Originally posted by Indusbreed


Tank is 55L.

[Smiling]... I know that the theoretical limit of the tank is 55L, but I\'m sure that you didn\'t drive it till the last drop of fuel was used? I\'m simply asking how much fuel did you use in order to have more accurate fuel economy numbers.

[kl7402001]

Sorry there guys .. I thought u guys already know cus I posted my driving habits a few post back ..

here its is again in more detail for those who weren\'t paying attention(read!!)
2 days out of 6day of the week that I drive my car I drive from sauga to Toronto to go to school Ryerson. Rest of the days i drive 15-20min to and from work taking Matheson. ...

Umm and I think my signature saids I drive a GT so I have a 2.3L engine ... its MT

Shifting around 3k rpm

[everfeb]

PiCASSO...BTW, thanks for thinking of me regarding the fuel economy tracking doc you posted a while back. I know very little about how cars work and I know even less about how to work a computer.
So I\'m just going to carry on doing my Mileage checks manually. Only takes a few minutes and not very often as I don\'t put a lot of km\'s on the 3. But thanks very much.
everfeb

[everfeb]

INDUSBREED...just wondering---do you know how to calculate L/100km?
everfeb

[majic]

everfeb,

YGPM