Cold Weather = Lousy MPG?

C

Clarkbug

Member
:
2003 Protege 5
Hey Everyone.

Just a quick question for everyone who has been driving around lately, especially those in the more Northern (I.e. Colder ) climates lately.

I headed home for thanksgiving this past week, and tracked my MPG as usual. However, I drove starting around 2AM and went from around Washington DC up to Utica NY through PA. On the highway with the cruise control set I usually get over 30 MPG. However, this time I was barely above 25.

The only thing I can think of is that the outside air was that much colder (it was about -9 with the wind chill) as I wasnt heavily loaded in the car or anything. I am due for an oil change shortly after this trip, and Im coming up on my 30,000 service in about a thousand miles. I only mention that because I havent done the air filter yet (yes, Im a bad person).

So has this happened to anyone else in the cold weather? Or do I just need to change my filters and plugs and see what happens?

Thanks in advance!

~Bug
 
my P5 looooooooves cold weather..... only reason I get worse Gas Mileage is because I get tempted to stomp the gas pedal more (shrug)
 
mooS mooS said:
my P5 looooooooves cold weather..... only reason I get worse Gas Mileage is because I get tempted to stomp the gas pedal more (shrug)
Click to expand...
Same here, that and I don't wanna leave the warm house as much!
 
^^^^


same here.

most cars run better with denser cold air rather then warm air. more O2 for the engine........

we use special gas up here in the north east which hurts our milage a little. not as much as AC does in the summer though!

-R
 
Calrkbug, I have the same problem. I don't idle the car for long periods to warm it up, nor do I drive more agressively than at other times of the year. My best guess as to the cuase of the problem is probably bcause of the formulation of gasoline in the area. Different regions of the country mandate fuel mixtures that reduce emissions at certain times of the year. Like Protege52003 said, I think that may be the cause.

Of course, it could be behavioral...like to much time driving with the defroster on (AC running) or extended warm-up/cold engine periods (running rich to warm the engine + more friction from cold internals/fluids) or more traffic this time of year (more people shopping + people slow down in the dark and now most of my commute is in the dark).

I any event, it makes me suspicious because during the summer I can run the car ragged...with AC and not drop below 26mpg around town (average 26.58mpg during September and early October). Last fill-up I got 23.9 mpg.
 
yeah, i think it's the gas. i haven't noticed a drop off yet, then again I haven't been driving much.

speaking of driving, any of you guys going to the MSCW meeting on the 7th?
 
Thanks for all the quick replies everyone. I was hoping my MPG would go up as well due to the colder air, which is why I was so surprised that it went down instead. Winter weather isnt fun to be out in, but cars do tend to run better....

But a few things to refute a bunch of that stuff.....

1. The gas I was getting the 25 MPG with I bought down here in VA, so my numbers shouldnt have been affected by the different formula. So unless they changed the formula all over the North East at once (which doesnt seem likely, since everyone else doesnt seem to have this problem), I dont know if thats it.

2. When its cold out and I'm on the highway, I select the defroster setting, but dont turn on the fan. So, the A/C doesnt kick on but I still dont get a foggy windshield as long as I keep moving. (I havent had time to do the mod yet, work is lousy)

So I dont know what it could be. I only idle the engine until the RPM's drop down, then take off. But I had a full tank of gas when I left, and drove straight through the night until I had to fill up again, so there wasnt any idling, or even any stop and go traffic.

Does it just mean its time for the plugs/air filter to cure my woes? Or do I need to wish for spring?

~Bug
 
Did you factor in wind direction/speed and elevation change? It's always possible you were driving against a stronger wind...
 
Clarkbug said:
Hey Everyone.

Just a quick question for everyone who has been driving around lately, especially those in the more Northern (I.e. Colder ) climates lately.

I headed home for thanksgiving this past week, and tracked my MPG as usual. However, I drove starting around 2AM and went from around Washington DC up to Utica NY through PA. On the highway with the cruise control set I usually get over 30 MPG. However, this time I was barely above 25.

The only thing I can think of is that the outside air was that much colder (it was about -9 with the wind chill) as I wasnt heavily loaded in the car or anything. I am due for an oil change shortly after this trip, and Im coming up on my 30,000 service in about a thousand miles. I only mention that because I havent done the air filter yet (yes, Im a bad person).

So has this happened to anyone else in the cold weather? Or do I just need to change my filters and plugs and see what happens?

Thanks in advance!

~Bug
Click to expand...

I got ~32MPG going from Connecticut to Rochester, NY (355 miles) and ~31MPG round trip from Rochester, NY to Toronto, Ontario and back.

Below freezing temps for the entirety of both trips. CT to NY on Friday, NY to Canada and back on Saturday.
 
Tire pressure plays a huge part in the winter. i keep my pressure at 34lbs in the winter, also don't idle just drive slow and let the car warm up slowly. even in the winter while still driving fast i get 24-26 mpg driving around town and on the highway still get 30+.
 
I can't say a reason for sure, but here are some interesting things that I've read various places:

1. Pretty much everyone has different "summer" gas, usually memorial day-labor day. They formulate it a little differently to reduce emissions, which I think means the gas in summer has a little less energy.

2. Filling your tank with 12 gallons in winter gives you more energy than 12 summer gallons because pumps run by volume flow (pretty difficult to measure mass flow) and colder weather=denser gas=more mass per unit volume

3. Driving habits affect mileage a lot...probably way more than any minor mechanical changes you make.

ok now that I look at this, I am just adding to the mystery so I'll shut up!
 
I was only getting 21mpg for a tank. I think i got a bad tank of gas though, because i didnt change anything at it went back up to 24 city and then another tank 30combined city/hwy. ... maybe it was the gas?
 
technically yes speed. air drag increases with the square of speed. so if you could have a car drive at 50 mph and then change the tranny so the same car at the same revs went at 70 mph, the faster car would use more gas.
 
I drove to WV and back over thanksgiving. Lots of mountians and average speed of 75 - 80mph 3.5k and above rpm. (I got a deal on 205/40/16's so they are 4% smaller diameter so TRUE speed was around 70-75)

904 miles total at 30.9 mpg total trip.

Various gas stations, weather was snowing on the way down. Drove at night Wed and during day sunday.

No A/C, no windows down, no roofrack.
 
Nomad said:
I drove to WV and back over thanksgiving. Lots of mountians and average speed of 75 - 80mph 3.5k and above rpm. (I got a deal on 205/40/16's so they are 4% smaller diameter so TRUE speed was around 70-75)

904 miles total at 30.9 mpg total trip.

Various gas stations, weather was snowing on the way down. Drove at night Wed and during day sunday.

No A/C, no windows down, no roofrack.
Click to expand...

If your wheels were smaller diameter, doesn't that also affect odometer readings?
 
Please log in or register to reply here.

Similar Threads and Articles

I
Slow to warm up in cold weather issue
Replies
4
Views
595
regnid
R

New Posts and Comments

R
    • Like
DIY inner tail lights CX90/70
Replies
4
Views
135
Silly Wabbit
S
H
Do
Replies
0
Views
24
HebDoc
H
SBMongoos
Getting close for new tires
2
Replies
35
Views
5K
P-51 Lover
P
S
New Transmission Costs
2
Replies
37
Views
6K
Lazy2.5
L
A
Tire size question - Help!
Replies
9
Views
350
Mazdiod2
Mazdiod2
T
  • Question Question
2007~2015 CX9 Battery light on after new Alternator
Replies
3
Views
147
TheDude88
T
View more…

New Threads and Articles

Back