Bad gas mileage revisited

[mr.weatherman]

Last winter I mentioned that my awd cx-7 does not like the cold weather, the mpg's go from bad to really bad. I call 18 mpg bad cuz I really thought I would at least get 20-22 mpg, really bad is 12-15mpg.

It seems that when temps get into the 20s and 30s, which they have the last month in New England (I'm MA to be exact) the car freaks out and guzzles gas as if it was beer.

I can usually get 300-325 miles to a tank during most of the year, but once it starts getting cold it goes down to 250-275 miles per fill up. I got about 110 miles on a half tank last week when it was in the upper teens and 20s in the morning, that's about 11-12 mpg..the tank holds 18.3 gallons right?

We have had a wide range in temps this month, during the warmer days the car behaves 'normal' then when it gets cold it guzzles gas, then goes back to normal when it warms back up, so yeah it's the cold weather affecting it if everything else stays the same (which it does), the temps are the only variable changing.

I had the dealer look at it last winter and I just sent them an email again this morning cuz 12 mpg is not normal..I better move somewhere warm or ditch the car which is what I'm going to do in June when the lease is up.

I have 35,700 miles on the car, and most of my driving is highway. I work 4am-noon so traffic is never an issue.

I had also mentioned that my car likes to shift from 6th to 5th a lot when it gets cold, I had it flashed in the summer. I did not notice anything diff. Now that the cold weather is back, its popped up again. I just saw a new thread about a similar issue, I'll have to see if its the same thing.

Thanks,

Mike

 

[Mazda3]

I have noticed the cold temp gas mileage drop as well. I get some of the better gas mileage on these forums and have no complaints about summertime mileage, but the mileage does drop for no apparent reason when the temps get cold. Just to clarify, this isn't because of warming up the vehicle and the AWD kicking in from snow driving. Its start before the snow and before the temp drops to warm-up weather. There has to be something in the tune that uses more gas in cold temps.

As far as the 5-6 gear thing there is another flash that just came out that will improve that.

 

[mr.weatherman]

Although it's usually cold when I head out to work in the morning (around 3:30am, I work at 4am!) I only warm it up for like a minute tops.

I'm also ez on the pedal, unless I'm passing or getting on the highway I rarely floor it. I don't think the RPM's have ever reached the 4000rpm line!

 

[erhayes]

In addition; winter gas formulations cause up to 10% loss in mileage.

 

[mr.weatherman]

I'm aware of the different type of gas blends, but I'm talking about seeing a different in the same fill up/same week.

Last week (or maybe it was the week before) we had a few cold mornings, in the teens and low 20s...I got about 120 miles on a 1/2 tank. A few days before that it had been warm, in the 50s during the day, 40s at night...I got about 170 miles on a 1/2 tank...I get my gas at the same spot and my driving habits don't change from day to day.

Again, the only variable that is changing here is the temps, especially feel it when its in the 20s.

I would like to think it's the gas or some other factor but it's the car I'm afraid. I'm hoping that by spreading the word, Mazda will eventually look into it and maybe flash the computer again.

 

[Int3grity]

Dude it's the dam car get rid of it like im trying to do. Nah just kidding this is happening to me now in Jersey one day is 30 one day is 60

 

[gosensei]

The low-fuel comes on around 16 gals. It doesn't go down to 18 gals. So, OP, you are actually getting a pretty decent gas mileage.

 

[erhayes]

I thought you were measuring actual fuel consumption. Gas guages are not a good method to make comparisons.

 

[Rick's CX-7]

If your main driving is highway, then try going to 89 octane for half a tank and see if your mileage improves. Cold weather allows you to lower octane a bit. Also, have the emissions recall done on your car....the number is 4907H.

Rick

 

[Nash04]

Ouch!

I too notice my gas mileage got worse since the cold weather arrive, now instead of being 16 mpg on hwy it's now about 13 mpg, I'm a pretty mellow person but seeing this gas mileage brings the NY city verbage out of me. As far as changing the octane, Dude, I've been using 89 octane since this summer and have not had any issues with the car, the performance is the same!

The only thing that I can think that might be causing this;

Is the Turbo not warming up enough during the cold weather which would cause the engine to suck more gas to keep the performance up to par but it's funny because my Jetta had a Turbo and never had that problem with it, oh! Yeah! I forgot, it's a VW...not a Mazda lol!

 

[1Sleepy93]

Cars are tuned to run richer in cold weather, so yes, your gas mileage is going to be worse than it was when it was warmer out.