ostrich

We are experiencing an unusually cold and snowy winter here in NE Ohio. During summer, I get a combined gas mileage of about 26-28 mpg (roughly 50% freeway, 50% local). In previous winters, I got about 24-5 mpg combined. However, this winter, I am dropping to about 21-22 mpg. I also changed my tires to Goodyear TripleTred for the snowy condition too.

Is this big drop in gas mileage most likely due to the cold temperature and snowy roads, or more likely to be due to the new tires?

I wonder what gas mileage the other 04 TSX owners get during their snowy winters?

MMsTSX

well, I can't compare mileage with you, I'm in the south and there's no snow here at all.

but I can comment that it's probably a mixture of three things.
one being the gas they sell in the winter.
two being the colder, more condensed air your engine is breathing.
three being the new tires.
it could be the rolling resistance of them, or the pressure settings of them,
or maybe even another factor.

it is also possible that other factors can also be added into the mix.
like maintenance stuff. your car is an 04 and is starting to age a bit.
clogged up filters, dirty injectors, etc. can contribute to the problem as well.

keeping the gas mileage high in a car, especially as it ages is a comprehensive strategy
of keeping all parts of the car in tip top shape. things like shitty winter gas and the
nice cold air that gives you that extra bit of power are out of your control, but there are
some things you can tweak or work on to help out some.

LukeaTron

I have an 04 6mt and in the winter I drop down to 17-20 mpg. Part of it is the heavy snow tires on steel wheels that I put on for the winter. My average mpg in the summer is around 22-24 but it's almost 100% local roads. I would wager your area has more ethanol in the gas this year for one thing. Different tires can move the mpg around a little bit too.

LuvMyTSX

Mine has dropped as well, as it always does in winter.

miked8887

I was getting 20.2 (city), but now I'm down to 18.6 since it got real cold

I would bet on 1) tire pressure dropping in cold, and 2) resistance from driving in snow. The snow imposes a lot of resistance I think (even though it seems counter-intuitive since its harder to stop in snow). I'm sure there are more factors.

visuelz

One time in the winter I got 11 mpg on all city. If I do all highway in the winter, I get about 22 mpg. If mixed, 18-19 mpg.

JimHolloman

Lower mileage in winter is both common and expected. Every car experiences more drag because the air is thicker. The snow and slush creates additional drag on tires. The gas blend is not as suited for mileage as the summer blend. Many people allow their car to idle more -- either to warm up or to stay warm. And, if you switch tires, winter tires generally have a little more drag because of softer rubber compounds and a tread designed primarily for traction rather than rolling efficiency.

Red@8

Ironic that the day after you post we are well above freezing and SUNNY in Cleveland today! I have only been here in CLeveland for less than 2 years now but I must say that the snow removal you have here is phenomenal especially considering the amount of snow the area gets. I am always amazed when people around here complain about it.

I get about 25mpg combined driving here in the winter on the oem tires. ~20mpg if its just city.

Since you were getting 24-25mpg in previous winters I would hypothesize that the current decrease is due to the new tires. Thats really the only variable that has changed significantly for you.

ostrich

Red@8, I agree with you that the Cleveland metro area does a pretty good job with the snow removal! Comparing to other cities that get totally paralyzed with just a few inches of snow, we certainly get much better services!

So, were you from Calgary? Don't you get much snow there?

I am also thinking that the tires really brought down the mileage.... we shall see. Thanks!

Red@8

I still call Calgary home, I am in Cleveland for school.

Calgary does get a fair amount of snow. They only started using salt a few years ago. Calgary is fairly wealthy and even then I have never seen snow removal there like I have here. I also spent a good amount of time in Saskatchewan as well, which completley redefined my definitions of "cold" and "snow". Too cold there to use salt and very rarely did I see any snow removal and they used to get a lot of snow. I guess coming from there I can really appreciate the weather and the road crews here.

bchoi930

i have an 06 AT, i get about 16mpg city.

Audioserf

This probably has more to do with the additives they put in fuel during the winter and the effects the cold has on tire pressure, than anything else.

hiptech

This may sound weird but here goes... I live in Phoenix but the temps here in winter can get to freezing. I gas up at local station about 2 miles from home and meticulously check my mileage at every fill up.

The station is located at a slightly higher elevation than my house and one of the "games" I play after filling up is to see how high I can get the trip computer to register on my return home. This usually involves coasting most of the way home (with little to no traffic on residential streets).

I know this isn't scientific or anything but I do believe there are sensors that must be adjusting idle speed and/or fuel mix differently depending on outside air temp.

When the outside temp is below 65F degrees, the best I can get is about 27-30mpg. But when the ambient outside temp is 70F or higher, I can usually beat 40mpg (with the A/C off).

Don't know if this helps but I do find it interesting and makes me believe that air temp plays a big part in fuel mileage.

LukeaTron

The air temp definitely does factor into how the ECU runs the injectors. When it's cold, the air is denser and has more oxygen per unit volume. The car needs to add more gas to mix to keep the ratio of oxygen to gas where it's supposed to be. The advantage is that you get more power out of each combustion (since there's more gas and air in the cylinder).

nbtx

It's mostly the BTUs needed to heat the drivetrain which are not used to propel the vehicle which cause lower fuel mileage. The ECM compensates for outside air temperature and density so your fuel mileage should be about the same winter and summer assuming your tires are properly inflated.

And the factory tires are optimized for low rolling resistance. Other tires probably are not so good.

LukeaTron

It compensates by adding more gas to keep the mixture the same which is part of decrease in fuel economy.

Saeyon

same as my 08..averaging about 270-280 miles per fill up

CraigMacDTA

I'm glad I stumbled upon this thread cuz I've been wondering the same thing over the past 2 months. I have an 08 6MT and I've been noticing a significant drop also. Does the fact that we have our heating/defrost and heated seat on constantly have anything to do with it also? I'm getting a combined 10.7L/100km right now...not sure what that is in MPG, but I usually average 9.6L/100km.

nbtx

More power per combustion given a constant throttle opening. However, since the engine is making more power per stroke, you can ease up on the throttle for a given speed. The amount of "power" to propel the vehicle is a constant regardless of air temperature - except for minor effects of increased air resistance, CV joint drag because of thicker grease, and there are probably a few more I'm missing now.

And yes, anything that adds load to the alternator like heated seats and increased blower speed takes additional power from the engine. There's no free lunch - the fuel in the tank provides the power.

TSX882

ever since i bought the car, which has been in the cold, ive had 1 brand new tire and 3 tires at 3/32 tread and it pulls insanely to the left, ive been getting 21mpg no matter how i drive, im assuming that after i get that fixed and get 4 new tires.

im optimistic and hopeful to be in the range of 25mpg mixed, which is where alot of people seem to be.

But i seem to be averaging the same as saeyon, at 290 miles to the fill up. i drive till 0 miles on the range. usually fill up 14-15 gallons. i dont mind paying 300 miles for 30 bux. use to pay for 19.2 gallons and drive 270-290 and if i got lucky 330. ive gotten to 315 in the TSX.

transit6404

Hmmm... After reading all the posts, I am surprised to see my own mpg calculation result.

Last Monday, I filled up all the way up and drove for 3/4 of the tank for a week and I fill it again to full and did a quick calculation and got 23.4 mpg with about 30% highway, 70% city-work. And I must say it's been in the single digit weather until last Friday here in Ann Arbor, so I am proud of the number I got.

Over the weekend, I drove to Chicago and I got 30.5 mpg aggressive highway driving (avg. 80-90 mph), but i guess it's because of the nice weather we get here (50s in Feb!!).

But on the way back, I drove in a 30~40 F environment, and my mileage dropped down to 27.9 mpg with easy highway driving.


Anyway, to your question, ostrich, i guess factors like the air, amount of ethanol added, rougher driving (being stuck in the snow half of the time) could lead to lower mpg.

Johns

Another reason for worse mileage in winter is a cold engine. If you idle the car to warm the engine (not really needed), your mileage will go down. If you run the car with a cold engine, your mileage will be lower until the engine warms, and that can take a few miles.