Mile Per Gallon!!!!

[sp535]

Dear all,

My cx9 Touring has 1800 mile for past 2.5 month and still have city/highway combined 13mile per gallon.

The dealer told me it will start to break-in (what does that mean anyway?) from 12,000 mile or so.

my previous car was Jaguar XJS V12 with 10mpg. I dont want to feel the same after selling my precious Jag with this lovalble CX9.

Please kindly advise whether this is normal or what to do to achive 16-18 mpg at least. by the way, I am using 87 regular unleaded.

Thank you.

 

[Durfdaddy]

gas mileage

Well...I can't say for sure because I drive a CX-7. After I had a flash done my mileage went down from an average of 19-20 to 16-17. I even saw 15 one time! I am using high octane for the turbo and that is hard to deal with.

I had them make sure ALL flashes were up to date and that got my mileage back up to 19-20. I even saw 21 today on the HWY!! Good times...

As far a break in time, I never had one as far as mileage. I am not sure how much I trust Mazda with my questions. These are new probs for them too.

 

[CX9 SportOwner]

Even very poor driving shouldnt yield anything near 13. I drive our '9 the way it was engineered to be, fast, and always get 20 to 21 combined.

 

[AussieCX9]

Dear all,

My cx9 Touring has 1800 mile for past 2.5 month and still have city/highway combined 13mile per gallon.

I feel your pain sp535!

I have just look at an online conversion calculator to measure US MPG as I only understang litres/100klms here in Australia.

This is my findings.....When I bought my CX9 2 months ago the economy was running at 9.4 miles to the US gallon.

Now I have traveled city/hwy 3000klms and my reading is at 11.7 miles to the US gallon.

Mazda reckon I dont have a problem because my fuel economy is getting better....what fuel economy??(piss)

I will let it go for another 1000klm but if there isnt any real improvement my Mazda dealership will definately hear me coming(fight)

 

[l-miwa]

Please kindly advise whether this is normal or what to do to achive 16-18 mpg at least...

There are a number of things that can affect your mileage:

Cold weather - Do you let your CX-9 warm up (using gas) before driving? It's a good idea, but it sucks gas. Even if you don't, the idle mixture and rpm are set higher while it warms up, also using more gas. I find that my mileage has dropped by about 2mpg just due to the colder weather.

City / suburb / highway - If you do a lot of downtown, stop every block driving, you'll be doing well to get 9-10mpg. In the suburbs with stops every half mile or so, I get about 14mpg, driving VERY conservatively. On the highway (at 70mph), I've gotten 21mpg a couple times. So depending on your mix of driving, your mileage will vary greatly.

Cruise control - The computer can modulate the gas pedal much more smoothly than I can. Thus it gets better gas mileage than I do! I use it on the interstate, I use it in the city, I use it whenever I'm maintaining a constant speed for any length of time. Definitely helps the gas mileage.

Trip computer - I installed a ScanGuage II (takes only a couple minutes to plug it in) and having the instant mpg feedback helps remind me to keep my foot out of the pedal when it isn't necessary. Just watching the mileage plummet to 4mpg is painful! You'll also be able to see where you're losing the mileage. If you're seeing 13mpg at constant speed on a flat road, there is definitely a problem!

All that said, if you're still getting mileage much worst than you expect, take it back to the dealer and see if there's something wrong. A problem with any one of a number of sensors could have the engine running richer than necessary.

 

[ceric]

I'll say being lead-footed is probably the major cause of low MPG.

I got (mixed 50/50% city/highway)
- 16.5mpg (1st tank)
- 16mpg (2nd tabk)
- ? (3rd, ongoing)
For a vehicle that is 4500lbs, these are good numbers.

I keep up with traffic and not trying to be 1st all the time to reach the next light.
Trying to time the traffic lights will also help MPG.

 

[njerald]

There are a number of things that can affect your mileage:

Cold weather - Do you let your CX-9 warm up (using gas) before driving? It's a good idea, but it sucks gas. Even if you don't, the idle mixture and rpm are set higher while it warms up, also using more gas. I find that my mileage has dropped by about 2mpg just due to the colder weather.

City / suburb / highway - If you do a lot of downtown, stop every block driving, you'll be doing well to get 9-10mpg. In the suburbs with stops every half mile or so, I get about 14mpg, driving VERY conservatively. On the highway (at 70mph), I've gotten 21mpg a couple times. So depending on your mix of driving, your mileage will vary greatly.

Cruise control - The computer can modulate the gas pedal much more smoothly than I can. Thus it gets better gas mileage than I do! I use it on the interstate, I use it in the city, I use it whenever I'm maintaining a constant speed for any length of time. Definitely helps the gas mileage.

Trip computer - I installed a ScanGuage II (takes only a couple minutes to plug it in) and having the instant mpg feedback helps remind me to keep my foot out of the pedal when it isn't necessary. Just watching the mileage plummet to 4mpg is painful! You'll also be able to see where you're losing the mileage. If you're seeing 13mpg at constant speed on a flat road, there is definitely a problem!

All that said, if you're still getting mileage much worst than you expect, take it back to the dealer and see if there's something wrong. A problem with any one of a number of sensors could have the engine running richer than necessary.

Run your tires about 4 psig higher than your manual says will help a little.

 

[Force-1]

My 20 mile commute to work is 75% hwy, 25% city, and I am averaging about 18.5 MPG in my 3 month old AWD GT.

I have made 2 R/T runs to Denver (900 miles) at average 80 MPH, and gas mileage is about 21. Okay with me, considering my CX-9 replaced an Escalade that got 14-15, no matter where I drove.

 

[sp535]

Update!!

O.K. after the lamp issue, low mileage, I changed from Guiffree Mazda to Manhattan Mazda. And they did all checkup to find out any error causing low mileage.

While I was happy to see them taking care of the car, we could not find any reason for the low mileage. The mechanic suggested to monitor some more cycle for fuel filling vs mileage and asked me to get back to him.

 

[bill42]

Well I just calculated my milage again using the fill-up to fill-up method, and my milage is getting worse- 13.5 mpg on the last tank which was 80% city driving. I have about 4000 miles on the engine so I would say it is broken in. I don't drive really slow but I also don't floor the car at every stop light. I know I could baby the throttle and get 15mpg, but I wanted to see how my mileage would be if I just drove the way I am used to driving. (my last car was a small volvo wagon with a turbo 4, and it got about 17 mpg when I drove it this way for city driving)
I knew the car would be bad but I never knew I wouldn't even get 250 miles on a 20 gallon tank!
I guess it is my driving, but man if I drove the car like I used to drive as a teenager I bet it would get 10mpg.
Anyway I still love the car. I guess I am complaining because there is really nothing else I can complain about this car.

 

[AreYouWithMe]

I got my 08 Touring Wednesday night (Former Exec car with 7k miles). I drive 100 miles to / from work and averaged 20 MPG on the first half tank on mixed highway / local.

 

[CX9 SportOwner]

There MUST be something wrong with your car. I LOVE taking off from lights fast, pass hard, fly around corners and curves (rails), and STILL average 20 to 21.

 

[bill42]

Just when I am about to accept that it is normal that my car gets 13.5mpg, the two posts above open up the mystery again. Are you all calculating you mileage by dividing miles driven by gallons added to top off the tank?
If so, then perhaps you others who get 20mpg have the lighter 2 wheel drive CX-9 which also has less friction than my heavy 4600 lb. AWD model.
Also, I drive mostly around town, from light to light, and I only get past 4th gear on the weekends. Therefore I rarely take advantage of the tall 6th gear overdrive.

To back up my low mileage, let me point out that MotorTrend seems to get similar mileage when they test crossovers of the same size as the CX-9. Their actual mileage is always less than the new EPA ratings. Compare this to the 2 posts above who say they are getting the highway EPA 20mpg for mixed driving... something just doesn't add up.

 

[AreYouWithMe]

Are you all calculating you mileage by dividing miles driven by gallons added to top off the tank?

If so, then perhaps you others who get 20mpg have the lighter 2 wheel drive CX-9 which also has less friction than my heavy 4600 lb. AWD model.
Also, I drive mostly around town, from light to light, and I only get past 4th gear on the weekends. Therefore I rarely take advantage of the tall 6th gear overdrive.

Yes I have the FWD model and calculated it total miles driven from fill-up to fill-up divided by total gallons added. My driving is about 30% pure highway, 40 - 50% "back roads" with a few lights and stop lights, and 20 - 30% more "in town" driving with traffic. I am routinely in 5th and 6th gear at 40-50 MPH on the back roads. My tranny upshifts at very low speeds.

I also drive conservatively and don't go Mach 5. I'm going to fill up tonight. I'll let you know what the MPG is.

 

[astraelraen]

I dunno about people getting 20+ mpg, but if you expect to get much better than 15-18mpg with a 4500lb AWD vehicle you are lying to yourself. It doesn't matter if its got a v6 or a v16, it weighs 4500lbs and has additional drivetrain friction of AWD.

 

[ceric]

Are some people talking British gallon here? It is bigger than US gallon, you know.
I also don't see how one can get 20mpg in city driving. For highway, one should be able to get 20-22mpg by following traffic and maintaining nearly constant speed.

I have AWD and loaded with accessories (hitches, racks, etc.).
I have been getting 16mpg (+/- 0.5) in SF Bay Area (mixed city/highway/traffic jams)
In city driving, weight is a major factor affecting MPG.
In highway driving, it is the wind resistance (drag coef x cross section area) and tire friction.

CX-9 has drag coef of 0.36 and the OE tires are pretty wide (at 245 vs 225 on Hondas).
0.36 is good but not great. Some CUV has drag coef of 0.32.


(heat loss and power train loss are present is both situations).
Anyway, 13.5mpg is not normal to me.

 

[SydneyGuy]

I've had my CX-9 for about 6 weeks now. Over that period the car computer tells me I have averaged 14.7 litres/100km. Doing the conversions using US gallons (3.79 litres = 1 US gallon) that equates to 15.47mpg average for the 6 weeks.

That figure is 10% worse than the mileage I used to get with my 5.7 litre V8 SS Commodore.

Note that I never use the air conditioning so that 15.47mpg figure would probably be something like 14-14.5mpg if I did use it.

With petrol hitting A$1.50/litre this week in Sydney (US$5.23/gallon) it is going to cost a lot to run this car for the next 4 years .......

 

[hss_Rao]

better gas mileage, but ?

It is around 5 weeks since I bought my CX9 sport FWD. Filled gas 4 times.
1st - 17.5 (87 Oct - 20% highway)
2nd - 16.25(93 Oct - 100% city)
3rd - 17.2(93 Oct - 100% city)
4th - 19.4(87 Oct - 20% highway)

Now I have around 1200 miles, but what I saw was the engine oil is close to the lower hole in the dip stick, probably 8 mm above the lower hole , and as I live in NJ, still using heater and no A/C.

Does anyone have this kind of oil consumption or what are your observations?

 

[Force-1]

I just filled up about an hour ago, and got 18.2 MPG on this tank, city/highway driving. Loaded AWD GT.

I noted my oil was close to the add mark last week, so I threw in about 3/4 of a quart. The vehicle has about 4100 miles on it, factory oil still in the block.

 

[hss_Rao]

I just filled up about an hour ago, and got 18.2 MPG on this tank, city/highway driving. Loaded AWD GT.

I noted my oil was close to the add mark last week, so I threw in about 3/4 of a quart. The vehicle has about 4100 miles on it, factory oil still in the block.

BTW I forgot to mention this. I have not driven over 55MPH in the frst 1000 miles, but the oil color is getting dark brown (kind of going towards black), comparing to my 06 Maxima-it retails the golden yellow color even at 3000 miles. What was the color of the oil before you topped it.