Mazda CX-9 Real World MPG



  • cericceric Member Posts: 1,092
    As I posted before, CX-9 has very short 1st gear (4.15?). It revs very high when you hit the gas starting off. This, of course, gives you the "zoom-zoom" feel but it costs you gas. Also, cruising at 40 mph, the CX-9 holds onto the 5th gear instead of 6th. I believe the 6th can handle it very well (try the M-mode). I believe Mazda programs the transmission to be more responsive while costing you MPG a bit.
    Besides, CX-9 is heavy (AWD at 4600lb when loaded with options). 3.7L engine eats more gas than 3.5L/3.6L that most competitors use (Pilot, Highlander).

    My CX-9 (after 6000 miles) has been doing 15.5 to 16.5mpg in SF bay area (metropolitan driving). I cruise highway at 75mph, and follow traffic vigorously.
    We have the usual traffic jams like everywhere when commuting.

    I don't see how people can get 13-14mpg normally.
    - check tire pressure
    - check alignment
    - check air filter for blockage or dirts
  • nxs138nxs138 Member Posts: 481
    We get about 16 in a mix of city and highway, and about 20 on the highway with our AWD GT. There might be something wrong if you're getting such low mileage (the lowest we got was a bit over 15 in the dead of winter), unless you're doing all city driving, then I can believe getting about 13.

    The CX-9 is not the only CUV that sucks gas in city driving...I've read similar reports about the Acadia, Highlander, Pilot, and even minivans (my colleague doesn't get better than 20 mpg on his Odyssee). Stop and go driving kills mpg on these puppies, no question about it.

    We're not too impressed either, even though we knew mileage wouldn't be too good, you always kinda hope that you'll do better. And when you don't, it sucks. Oh well....
  • gogators93gogators93 Member Posts: 3
    I know there is a differenct in AWD vs FWD but what about if you get the towing package? We just bough a new 2008 CX-9 GT two days ago with a towing package to tow our sportbikes up to the mountains and to do track days. We haven't filled up the tank yet so I have no idea what mileage we are getting yet. But the towing package does include a special ECU program. Just wondering what the they do the computer and if it affects gas mileage?
  • cericceric Member Posts: 1,092
    From other forum, people with tow package have reported similar MPG. Tow packages includes larger tranny cooler and higher volume of coolant (bigger radiator) and ECU programming (and of course, the 25-28lb hitch). The ECU probably only differs when the load is high (such as towing).

    One indicator I use regularly is that when the fuel indicator at the 1/2 mark, if I get 150miles on the trip meter, I will get about 16mpg at the end.
  • skc7skc7 Member Posts: 4
    I also have a 2008 AWD GT with tow package, but haven't towed anything yet. I did not necessarily want the tow package, but the rest of the options, color, etc., was what I wanted. To date with 4700 miles I get 15-16 mpg with all city driving, 20-23 mpg with all highway driving, and 18-19 mpg with about a 50/50 mix of city and highway. That's about what the EPA sticker states. I'm not disappointed as this is probably about the nicest driving CUV as there is and I've driven the MDX. Acadia, Veracruz, and others. Nothing came as close as the CX-9 to the sporty handling and steering that I was accustom to and I was driving a G35 Infiniti which is probably one of the nicest driving sport sedans as there is on the road.
  • gogators93gogators93 Member Posts: 3
    I have to agree with the driving. The CX-9 drives great and we traded in our BMW 530i which drove smooth as glass. The 20 inch wheels provide a little more feedback through the road but I like that to be honest and driving a corvette as my car, I'm used to firmer rides.

    Glad to know the tow package doesn't affect the mileage as we will probably on be towing with it a few times a year but had to have it.
  • cx7lovercx7lover Member Posts: 90
    People realize the tank has at least 2.5 gallons left when the light comes on.

    This is the key in calculating MPG.
  • steverstever Guest Posts: 52,454
    I must be missing something - the amount left in the tank shouldn't matter.

    What the mpg calculator (either on the car or the one in your head) should be figuring is how many miles you drove on the number of gallons you used.

    So, if you drove 200 miles since your last fill up and you filled up today and put ten gallons in, you got 20 mpg no matter if there were 2 or 5 gallons left in your gas tank when you pulled into the service station.
  • cericceric Member Posts: 1,092
    Over the years, I have found that the "click-off" point at every pump is different (especially at different stations). You will see some variation with the click-off method when measuring MPG. However, if you do it over a long period of time, it is acurate.
  • steverstever Guest Posts: 52,454
    I have 125,000 miles of fill-ups on my van, and I could skip entering a whole tank in my spreadsheet at this point and barely affect the lifetime mpg on it.

    I still don't see what difference filling up with 2.5 or 5 or 10 gallons in the tank has to do with calculating your mileage though.
  • cericceric Member Posts: 1,092
    Hi, All:
    I have installed a ScanGaugeII on my CX9 for about 1000 miles now. I am here to report my findings. I used the ScanGauge as the trip computer that is missing on our CX9 (the 2009 model shall have it!)
    On my CX9 GT AWD (loaded with accessories and options - saved DVD entertainment system), I found that
    - it is easy to get 22 mpg with CX9 on highway. On my trip to Sacramento (a bit hilly on some portion of the roads), at 70-75 mph I was able to get 22 mpg w/o much effort.
    - it is no so easy to get 15mpg on city that full of lights and stop signs. Unless you can time lights perfectly and acceleration so gently (to the extent that does not piss off your fellow drivers), it would be hard to get 15mpg on this heavy CX9 with short 1st gear (4.15 ratio). With some try and error, I am able to do it now with help of ScanGauge to show me the instant MPG. The idle easy kills the MPG you tried so hard to improve. A red light auto-shutdown and start (like in hybrids) would be nice.
    I did try to drive it like what I did to my BMW, I consistently get 10-12mpg on city street. This what a heavy vehicle with short 1st gear can do to your MPG. It revs hard to get you off line (zoom-zoom).

    Overall, since my commute is a mix of city and highway, I was getting around 16mpg. With the help of ScanGauge (to change my driving habits), I am consistently getting around 17mpg. As I said, there is not much you need to do on highway other than maintaining constant speed (at whatever you desire). The trick is to be gentle and smart on city streets.

    Of course, what I found is not ground breaking. It is all common sense, really. However, if you are getting 13mpg now, you should know what is wrong now....

    P.S. I have K&N filer in my airbox. I will change it back to OE filter and see what happen to the MPG.
  • bluerublueru Member Posts: 5

    I have been contemplating purchasing a Scan Gauge II for our CX-9 since it does not have a mileage computer (ridiculous on a $30,000 + vehicle!). Would you say it is worth the money? We recently moved from OH to Eastern PA and even going through the mountains at an average speed of 65 - 70, we averaged close to 26 MPG! We were in SHOCK! Anyway, just wanted to let you know if you do drive with a conscientious effort, it is possible to get noticeably better mileage (~18/19 in city, 24-26 highway). Please let me know about the Scan Gauge.
  • cericceric Member Posts: 1,092
    To me it is definitely worth the money ($159 from eBay - free shipping).

    ScanGaugeII is in short supply now (because it is so popular, thanks to the gas price). Besides the trip computer, you also get the Scan and Gauge. Scan functions to see error codes and look up the codes on internet (hope you never have to use it!) and clear them if you want to.
    Gauge functions allow you to monitor many parameters of the vehicles such as coolant temp, battery voltage, on and on. If you are not technology challenged, I bet you would love it. Installation is super easy (Doable in a couple minutes). I put it in from of the "trip meters" (Odometer) with Velcro strips that came with the ScanGuageII.

    We all wish that the CX9 came with a trip computer (2009 model will have it), but even if it did, it wouldn't have the extra functions you get from ScanGaugeII.

    I am surprised that you got 25-26mpg on highway. I bet you have a FWD.
    As I said, CX9 (with 0.36 drag coefficient) is very aerodynamic on highway. One can easily get good mileage on highway if one holds the pedal steady. On city street, you definitely need the help of ScanGaugeII to get better mileage (choose a better commute route, for example). I am getting 1mpg better per tank. That is 7% saving (out of 16mpg). Assuming that I drive 12,000 miles per year. I would need 750 gallon (on @16mpg). 6% of that is 45 gallons. At $4 per gallon, that is a saving of $180 per year. $159 is recovered within 1 year of driving. That is in addition to all the extra gauges and a great diagnostic tool.
    Besides, one can use it on all vehicles, not specific to the CX9 (after some initial setup steps for Trip functions).

    P.S. I am not a ScanGaugeII salesman :)
  • bluerublueru Member Posts: 5
    Thanks for the info. I would definitely consider you a salesman now, I am going to buy one based on your comments and info. All the best to you and your CX-9. :shades:
  • nxs138nxs138 Member Posts: 481
    Do you have to calibrate the scangauge before use, or is it ready to go out of the box?
  • cericceric Member Posts: 1,092
    You need to set engine displacement (such as 3.7L, 6-cylinders, etc.) out of box.
    Then, you need to adjust the error of fuel consumption once.
    The procedure is to
    - fill up at the pump
    - drive at least 1/2 tank (I did 3/5)
    - check fuel consumed in ScanGaugeII (say 11.4)
    - fill up again at the same pump (click-off/top-off), take down reading at the pump
    (say, 11.7)
    - proceed to adjust the error in ScanGauge (in this case 3%).
    From then on, the fuel consumption should be very accurate.
    OBDII monitors fuel consumption by injection counts. Therefore, a small error
    might be present due to other factors.

    It is important to pump gas at the same station and the same pump to eliminate uncontrollable factors. Let it click off 2 times to be sure.
  • msuvetmsuvet Member Posts: 54
    We took a 800 total mile trip in July.

    We had a car-top carrier (pushing the 100# total roof-rail capacity), 2 people + 2 big dogs (~ 480# live weight total), plus some additional cargo in the vehicle where we could fit it.

    1/2 the trip was freeway, going 75 mph. Got about 21 mpg for that leg.

    The other half was non-freeway highway, going about 65 mph. But more passing on 2-lane roads there with often heavy acceleration (it was GREAT for passing). Got about 22-23 mph then.

    AC going for 99% of trip.

    That was better than I was expecting considering the carrier and total cargo weight.

    I'm getting about 17-18 mpg in the car driving solo, mixed 65%35% highway/city driving. That improved from closer to 15-16 mpg earlier in the winter/spring. I also changed the oil to synthetic at 5000 miles (right before the trip).
  • cericceric Member Posts: 1,092
    Please see my CarSpace album. I took them with my lousy Moto Razr cell phone camera. My digital camera is broken. I am shopping for one.
  • inlinerinliner Member Posts: 5
    I have got 850 km (530 miles) on the odometer of my 2009 GTX AWD. The trip computer (thanks Mazda for this improvement in the 2009 model!) shows that the average MPG is 19.8. City/highway - 40% / 60%. A/C is always on. Average number of passengers: 2. Terrain: flat.

    The car is still under 1000 km so I don't drive it too fast - max. 100 km/h (60 MPH). I am currently quite happy with this MPG, it's similar to what I get on the other car - a toyota camry 1998 V6 3.0L.
  • piroguepirogue Member Posts: 4
    we just bought a 2008 touring model with trip odometer A/B???? Did some come with it and some with out it???

    <a href="'s Album/Oct01_0002.jpg/page/photo.html#pic

    BTW we love the new car!
  • piroguepirogue Member Posts: 4
    here it is hoto.html#pic

    not sure how to use url function to make address smaller.
  • maltbmaltb Member Posts: 3,572
    I think you are confusing the trip odometer with the trip computer in the 2009 CX-9.
  • piroguepirogue Member Posts: 4
    Sorry, I was happy when I seen the trip odometer and thought I has a special vehicle. I've been confused all this time. :confuse:
  • piroguepirogue Member Posts: 4
    Probably so, sorry about that. That's the only way I have ever calculated milage and never believed the computer. Too each his own(respectfully) :confuse: .
  • cericceric Member Posts: 1,092
    In fact, trip computer (if calibrated well) is likely more accurate than your usual rudimentary miles/gallons method. Why? Because you really cannot trust the "gallons" reading from the pump. Yes, all pumps are periodically tested for accuracy, but pumps of gas stations click off at different thresholds. In my experiences, the differences can be as much as 1 gallon (fill-ups).
    In order for the miles/gallons method to be accurate, you have to fill up at the same station and, even better, the same pump between fill-ups.

    I have a ScanGaugeII installed and calibrated (with 4.4% error adjustment). So far, it has been very accurate within 0.2 gallons at fill-up (or ~0.2mpg)
  • nastacionastacio Member Posts: 370
    Just filled up the tank for the first time. 16 mpg in urban traffic, not bad. Will average out over the next fill ups using "odo B" to keep track of eventual improvements.

    I know it is heresy, but comparing it to the Sienna minivan it replaces, the engine needs its revs to move.
  • bobw3bobw3 Member Posts: 2,989
    I still don't see what difference filling up with 2.5 or 5 or 10 gallons in the tank has to do with calculating your mileage though.

    It dilutes the error rate. Let's say for example the pump you're using sometimes adds an extra 1/10 of a gallon of gas more or less. Adding that 1/10 of a gallon to a 2.5 gal fillup will create a 4% error (.1 / 2.5 x 100), while that 1/10 gallon pump error will only account for a 1% error on a 10 gal fillup (.1 / 10.0 x 100). Let's say your pump error is 1/2 gal because it's flowing faster or slower, more is released on the click, you're holding the pump slightly differently, etc. That 1/2 gal difference will create a 20% error on a 2.5 gal fillup vs only a 5% error on a 10 gal fillup.

    It's basic statistics. The larger the sample size (i.e. the quantity of the fillup) increases accuracy (eg MPG for that fillup).

    That's also why scan gauge really isn't accurate for snapshot MPG ratings, since MPG is Miles Per Gallon and if the car only moved a few feet and scan gauge tried to calculate a Miles Per Gallon number based on a few feet of driving, it wouldn't be very accurate in comparison with calulating a MPG over a hundred mile range. So if Scan Gauge calculates that it took 0.023 gal to travel 6ft that would equal 20.24MPG (0.023 x 5280 / 6), but if Scan Gauge was 1/100 of a gallon off and the actual amount used was 0.033 instead of 0.023, then the MPG would actually be 29.04MPG, so by being 1/100th of a gallon off, the MPG inaccuracy was 43% off.
  • cericceric Member Posts: 1,092
    My daughter is in 6th grade. Her science project this year is MPG vs PSI.
    My CX9 GT-AWD played an important role in this. Here is the prelim result.
    On a stretch of 2-mile local road w/o light/stop sign.
    Each data point was obtained by averaging four data points (back and forth twice to counter slop and wind effect). Vehicle was maintained at target speed with cruise control.

    35 40 45 50
    40 27.3 26.4 25.4 24.7
    35 26.7 26.4 24.8 24.7
    30 26.4 24.8 24.5 24.7
    25 25.6 24.4 23.7 23.5
    20 24.3 22.8 22.8 21.4
    PSI (all four tires) - warm

    As you can see the CX9 is well-capable of doing 27mpg provided that
    - run tires at 40 psi (MAX=51psi), it is a bit bumpy...
    - maintain speed at 35-40 whenever possible on local roads.

    My daughter and I spent the entire afternoon for that data.
    BTW, the TPMS lights came on at 20psi (not 25psi or above).
    It went away when I pumped them up to 35psi (my typical) and CX9 reached
    15mph from start.

    Also, a PSI drop of 40/35 down to 20 costs you ~10% drop in MPG.
    The MPG was based on my ScanGaugeII, which was +7% compensated.
    I have calibrated it for almost 1-year at the pump. It has been very accurate
    now (+/- 0.05 gallon error out of 17-18 gallons)
  • tidestertidester Member Posts: 10,059
    It's basic statistics.

    Yes, but basic statistics depends critically on using correct data. The departments of weights and measures in the various states regulate the accuracy of gas pumps to be about 6 cubic inches per 5 gallons. Since there are 231 cubic inches to the gallon, that works out to a relative error of just 0.5% per gallon pumped, not 20%

    If one is rounding off their numbers to the nearest 10th of a gallon then one is just being lazy. The price you actually paid for the gas and the posted price per gallon are sufficient to get an appropriately accurate measure of the volume of gasoline that you pumped.

    And, speaking of statistics, the "Law of Large Numbers" tells us that whatever errors you incur at each fill up will tend to the correct average over the course of time. :)

    tidester, host
    SUVs and Smart Shopper
  • tidestertidester Member Posts: 10,059
    That's really nice! I was going to make a graph of your daughter's data to post but I just don't have the time right now (it's late). Maybe tomorrow - or someone else would care to plug it into Excel. (Hint, hint!)

    tidester, host
    SUVs and Smart Shopper
  • bobw3bobw3 Member Posts: 2,989
    Your PSI and MPG from Scan Gauge prove my point exactly. For the first four 2-mile stretches at 40PSI, Scan Gauge calculated between 24.7 to 27.3 MPG for the exact same distance, speed and conditions over a 2 mile length, so on a 2 mile stretch it's reading varies by 10%. If you would have driven 200 miles instead of 2, then the Scan Gauge would have been more accurate, and vice versa if you'd only have driven 0.2 miles.

    It would be interesting (but very timeconsuming) to see measure the accuracy difference by only driving 0.2, 2, and 20 mile lengths.

    40 27.3 26.4 25.4 24.7
    35 26.7 26.4 24.8 24.7
    30 26.4 24.8 24.5 24.7
    25 25.6 24.4 23.7 23.5
    20 24.3 22.8 22.8 21.4
  • bobw3bobw3 Member Posts: 2,989
    "works out to a relative error of just 0.5% per gallon pumped, not 20%"

    Correct, but that's only the "fuel actually pumped" vs "what's shown on the gas pump gauge accuracy"

    What I'm talking about is the accuracy of person's ability to fill up the tank to the same level every time when they fill up their tank and then calculate their MPG. Even if the pump is 100% accurate, the point at which it clicks and shuts off varies a lot, depending on the speed of the fuel flowing into the tank, position of the nozzle, etc.

    Your original question was why it made a difference if you calculated MPG on a 2 gallong vs 20 gallon fillup and that's what I was trying to explain. It's the inaccuracy of the fillup (not the pump) that creates the error, and that error (which relates to the Law Of Large Numbers) will create a larger MPG inaccuracy the less you pump.

    Another way to think about it is to imagine if you drove one mile, filled up the tank and calculated MPG. The drive 100 miles, fill up the tank and calculate MPG. Which do you think will provide a more accurate result? Yes, it's an extreme example, but it shows that when trying to increase the accuracy of an MPG calculation it's better to drive more miles.
  • cericceric Member Posts: 1,092
    You have mistaken my data.

    The four numbers at the first row represents the MPG collected from various speed (35, 40, 45, 50 mph). Each data point is an average of four trials (back and forth twice). The ScanGaugeII computes MPG every 1 second or so. I reset the trip computer at the start and observe the average MPG at the 2-mile end. There are other factors that cause variations more than the ScanGaugeII such as the wind resistance. (on the day of our test, it was pretty windy) I also employed the cruise control to avoid human foot pressure variation on gas pedal.
  • tidestertidester Member Posts: 10,059
    Your original question was why it made a difference...

    Actually, that was Steve's question, not mine.

    What I'm talking about is the accuracy of person's ability to fill up the tank to the same level every time ...

    The information for doing it correctly is available based on what you pay and the price per gallon for your current fill up AND your previous one. Nevertheless, you have a point because most of us are not going to take the extra bookkeeping steps. :)

    tidester, host
    SUVs and Smart Shopper
  • steverstever Guest Posts: 52,454
    It's the inaccuracy of the fillup

    Well, ok, but I live in a perfect world and Tides will vouch that my mpg spreadsheets are accurate out to 9 decimal points. :shades:
  • tidestertidester Member Posts: 10,059
    Tides will vouch that my mpg spreadsheets are accurate out to 9 decimal points.

    Absolutely! But you never did tell me how you measured your fill ups to the nearest molecule or distance travelled to the nearest millimeter! :P

    tidester, host
    SUVs and Smart Shopper
  • bobw3bobw3 Member Posts: 2,989
    okay, okay I give up! :P

    My basic point was that point and short distances measurements aren't as accurate as those measured over longer distances.
  • steverstever Guest Posts: 52,454
    Point taken. :shades:

    It is interesting how the theory works out. I have a spreadsheet with ~400 tanks over a decade on my minivan and I could delete a few of them and it wouldn't affect the lifetime mpg. At least not out to one decimal point. :D
  • inlinerinliner Member Posts: 5
    Al right. I have had my CX9 for over a year now. It has 46K km (around 28.5K miles) on the odometer. I have not reset the trip computer for approx. 25K km (around 15K miles). The average I have got based on the trip computer readings is 13.2L / 100 km (17.8 MPG).
  • wdhytewdhyte Member Posts: 92
    our 09 we got back in Aug has about 4400 mi on it and the avg is 17.5 ...that w/one long trip between TX and MO and the rest of the time all here in the metromess.
  • rightleftyrightlefty Member Posts: 1
    Does anyone know why the 2011 is rated 2 miles per gallon better. Everything I have read says the 2010 and the 2011 are the same. I cant figure out how it is getting better mileage. Mazda lists the 2010 as 16 city and 22 hwy and the 2011 ,..17 city and 24 hwy. Anybody know whats going on ?
  • circlewcirclew Member Posts: 8,666
    Engine components tweaked and computer chip reprogram...not too much but 10% gain in efficiency.

    Makes you wonder why it wasn't done to the 2010...

  • saltydoggsaltydogg Member Posts: 3
    I wonder if it would be possible for the dealer to load the 2011 chip program on a 2010. I just bought a 2010 CX-9 GT this weekend. My wife will use it to commute 90 miles/day so every mpg counts!
  • circlewcirclew Member Posts: 8,666
    Probably not. Here's an update. Stick with stock and check tire pressure each month.

    Just did the same! CX-9 GTAWD/MRB/RLG) for her!

    Mazda says fuel saving improvements were a outcome of work done on a model&#146;s AWD differential rigging carryout, engine optimisation for improved explosion control (during deceleration as well as at resting as well as reduction in delivery attrition.

    Depending upon various, new 18 as well as 20 in. amalgamate wheels will set a 2011 Mazda CX-9 detached. The brand new alloys are lighter than prior to as well as come wrapped in tyres that suggest improved rolling insurgency (better fuel saving.

  • dogdoc1997dogdoc1997 Member Posts: 32
    MY 2010 CX9 GT FWD after 2 weeks is ONLY GETTING 13.3 according to its computer, how accurate are these; my wife is freaking out; her BMW 530 got at least 16 in the city...these are not even close to the posted sticker values; wonder if anyone ever sued a car company over missing the mark; DO NOT LAUGH, Mazda got sued and lost years ago when the MPH on the RX8 did not come closeto what was advertised; my neighbor was in on the class action suit,; the service writer says some get better as the car breaks in, some get worse? :sick: dogdoc
  • cericceric Member Posts: 1,092
    edited January 2011
    Short drives give you 13mpg.
    That is perfectly normal if you know how EPA do the tests.
    My wife's Prius gets 33mpg all the time on school routes, which is about 2 miles away with several stop signs and lights.

    Take the CX9 on a long trip, you will get 22 mpg AT LEAST!
  • inlinerinliner Member Posts: 5
    I have had my Mazda CX9 AWD for more than two years now. I haven't reset the onboard computer for about 75-80K km. According to the computer, my average is 13.2l/100 km (21.4 MPG).
  • robr2robr2 BostonMember Posts: 8,805
    Engines take some time to break in. Don't be suprised that it may take up to 10K miles before peak mpg is achieved. Further, actual mileage is affected by length of trip, weather, engine temp, amount of alcohol in the gas, et al.

    Further, if you have complaints - point them at the EPA. Mazda did not come up with the numbers, the EPA did.
  • cubanomxcubanomx Member Posts: 6
    This is not true. I have a brand new cx9 2011 sport and MPG is terrible. I'm finishing a chart right now (I will post in minutes new info) but I'm really dissapointed with the MPG advertised and real results.
  • cubanomxcubanomx Member Posts: 6
    On City with no traffic at all (at 02:00am) I made 17.5MPG (driving 23km= 14.3 miles)

    Today morning with heavy heavy heavy traffic I made 8.9 MPG!!! (26.4 L/100Km - 3.78 Km/L). This last values are horrible numbers.

    In the next weeks I will have a highway driving (310 miles) so I will check the MPG consumption in highway.

    Some weird stuff I see on the new CX9 2011 is I can go at 40miles x hour and the gearbox is in 6th gear. I read in the past 6th gear is only at highway but seems the new cx9 have a new programming (stupid) because MPG is horrible.
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