First winter with my HHR and I have been getting 33-37 mpg all summer. Now it's stuck on 32.5 mpg ever since it got cold. Does anyone else experience this? A friend of mine says his Nissan does the same thing in the winter.

First winter with my HHR and I have been getting 33-37 mpg all summer. Now it's stuck on 32.5 mpg ever since it got cold. Does anyone else experience this? A friend of mine says his Nissan does the same thing in the winter.

OMG yes! It's not just an HHR thing, but the DIC msure makes it more obvious. I have lost about 3mpg.:(

It's unavoidable, in any car. The colder, therefore denser air requires more fuel to maintain correct air-fuel ratios.

On turbo cars, this effect can also be exacerbated by the fact that the turbo will boost harder, sooner, thus using more fuel.

A more subtle aspect is that the car itself becomes harder to "push around" in cold weather. This is a twofold effect:

1. Aerodynamic drag increases with the denser air.
2. Wheel Bearing and transmission assemblies, as well as drive axles, induce more parasitic drag when cold. In many cases, save for trips of an hour or more, some of these parts never even get to optimal operating temperature in very cold weather.

My mechanic told me they add something to the fuel in winter to keep it dry and that knocks a few percent off your mileage also.

Last year it happened to my truck in 1 tankfull even though it had been cold for weeks. ---> about 3.5MPG

First winter with my HHR and I have been getting 33-37 mpg all summer. Now it's stuck on 32.5 mpg ever since it got cold. Does anyone else experience this? A friend of mine says his Nissan does the same thing in the winter.

Winter fuel blends have a negative effect on fuel economy. Be happy that you are getting 32 mpg though because I'm lucky to get 21 mpg right now during my winter drives.

In the cold winters, my mileage would drop dramatically. More time ideling and getting the car up to temperature for "proper" engine running. Also I was driving in slush and snow, slow and go. That was why I moved south. I haven't had the HHR into the snow belt in the winter in about three years..

One big issue is a winter gas blend of 10% ethanol in most states at this time of year. It will drop your MPGs 2 to 3 miles. One reason I stopped using 85% ethanol in my 09...

It simply takes longer for an engine to reach operating temperature in colder weather so the engine spends more time in richer fuel modes.Toss in the other factors(blended gas,increased driveline friction,etc.) and there's your loss of mileage.

Mine's gone up from 19 to 23 since July (100% city driving). But, my hunch is that's entirely due to me not idling with the A/C on while eating lunch.

My remote starter on cold mornings has a lot to do with my decrease.

Definitely. Between longer time spent warming up and the "choke" effect of adding extra fuel when the engine is cold I've lost about 3 mpg.

Weird.
I drove 175 miles round trip to Mystic, Connecticut yeterday.
Zeroed the MPG before leaving.
90% Interstate 10% good, long secondary roads with few lights.
about 35-40° F

32.8 MPG on the DIC :smile:

Weird.
I drove 175 miles round trip to Mystic, Connecticut yeterday.
Zeroed the MPG before leaving.
90% Interstate 10% good, long secondary roads with few lights.
about 35-40° F

32.8 MPG on the DIC :smile:

Not so weird, one long trip is much more efficient then several short trips, especially in the cold. Everything is heated up and the parasitic drag Bill mentioned is much less of a factor... Besides, 35 - 40 really isn't that cold.

Not so weird, one long trip is much more efficient then several short trips, especially in the cold. Everything is heated up and the parasitic drag Bill mentioned is much less of a factor... Besides, 35 - 40 really isn't that cold.

It's colder than summer and 31-33 is what I was getting on long highway roundtrips then.
I'm not a hypermiler per say but I set it at the speed limit in bad weather when I can.
I have been getting less MPGs but I have been doing more around town driving.

I'm not complaining anyways :beer:

I don't know about y'all, but man my little HHR has a lot more power when it is cold out. This is my first winter, and I can really feel a difference when the temps drop. It makes sense that the denser air charge needs an enriched fuel flow....both adding up to more power. Feels great. Costs more. Talk about cold air intake. ;)

One observation....has anyone noticed your fuel economy on trips dropping when it is raining? On my road trips, I have noticed that my economy drops at least 2-3 mpg when in an average rain. I am attributing that to the tires pushing a small wave of water, or tire slip at some microscopic level. BTW, I have new all-weather Kumho tires on the car, so it is not a "Firestones" issue.

God Bless, Marc

I've dropped a couple MPG from what I was getting in September. I attribute the drop in mileage to the stations switching over to a winter blend of gasoline which causes lower mileage.

I know at one time it was true that in the NW there was a required by law switch in the fuel being sold during the winter. However, I haven't checked to see if that is still the case. I just hope it is and in the spring I expect my mileage to improve again.

I am down to 31.9 today as it has gotten colder.

wow ive been happy with 32 mpg now im looking foward to the spring lol

Part of the lost mileage may also be attributed to lower water temps. I have never really kept track of water temps and mileage but I think there is a relationship there. Probably more effecient at 200* than at 175*
Considering blocking off front grill to lower wind drag and help keep water temp up in Winter.
Some of the guys on the hypermiling web sites are doing that and claim it helps. Now your car will make more horse power (use more fuel to!) in cooler weather but not sure how that effects mileage. In fact some of them are using a WARM air intake and claim it helps mileage.

denser air= more fuel plain and simple. winter blends are pretty much myth nowdays. good friend of mine works as a "fuel blend auditor guy" (dont really know what the position is called) at the bp refinery here, he is there to verify the amount of ethanol in the fuel and other additives. he said all year the ethanol volume (in ohio its 10%) is kept the same and has been like that for quite a few years to stem rising fuel prices (high fuel prices actually hurt oil companies believe it or not) and according to him at least with bp the additives do not change through out the year. just my two cents.

I drove to work in a cold rain this morining, and I'm still sitting at 32.7mpg. Do you guys let them idle in the driveway to warm up? I do not. I'm just easy on the gas until the gauge starts coming up, which doesn't take long moving the vehicle.

winter blends are pretty much myth nowdays. good friend of mine works as a "fuel blend auditor guy" (dont really know what the position is called) at the bp refinery here, he is there to verify the amount of ethanol in the fuel and other additives.

That is true for gas, but the additives for diesel changes... Not much of an issue for HHRs :o)