OK, so winter has set in with a vengeance here in North East Ohio and my MPG has dropped like a stone.
Not only is it cold (we'll drop to 17 tonight! ), dark (both to and from work I have to run headlights and the heater fan, and that won't change for the next 2 months) and snowy (that won't change for at least 3 months), I've had a sharp increase in city driving to haul my two sons back and forth to basketball practice. That, and I think my station has changed to winter blend (how do you find out? )
So with all that, I didn't even make 19 MPG last tank, and I was seeing upwards of 24 just a couple of months ago. That's a 20% drop! This stinks, even with fuel back down to $1.75/gal.
What can I do to help my MPG? I keep my tires at sidewall max, coast in neutral when I can, DWL when I can't, and work hard at timing lights. I'm working with a 12-year old automatic with 200K+ miles, is there anything I can do or is this it? (Cardboard-and-duct-tape mods are not an option, for she-who-must-not-be-denied would not approve. )
Unfortunately, there's not much more you can do in the winter that you couldn't have done in the summer.
Grille blocking, as mentioned above, can be done stealth-style behind the grille or directly against the radiator (the latter I described as "radiator blocking" to differentiate since I did it mainly to test cooling in preparation for my grille block). WAI could help too.
Another thing that might help is to pre-heat the interior. I've been thinking of putting a space heater in the car and an extension cord going to the inside of my house. In the morning I'd plug it in and leat it heat the interior so that when I get in I won't need to use the fan and I won't be cold. Of course, that brings up huge fears of causing a fire.
Stealth aero mods include better hubcaps, removing the FM antenna (improves reception with an FM transmitter on your iPod and you can still pull in local or strong stations), and a belly pan.
I removed my FM antenna and installed an inline FM modulator on my radio for my MP3 player. The MP3 player works great through the radio, and stations transmitting within ~20 miles are listenable w/o too much objectionable static. There are about 3 or 4 stations that come in perfectly clear, even with no antenna on my truck.
Not much you can do. Move to Florida for 3 months. Just get outa there before you have to have the a/c set on full blast all the time.
What I personally noticed is that if I park in the garage it usually doesn't get below 32 in there since I insulated it real good. The vehicle warms up quick. I don't let it sit around ideling as all that does is warm the motor. The rest of the drivetrain is stone cold. I just drive and that way the entire drivetrain warms up together and is more efficient faster thus useing less fuel.
If it is real bitter cold where you live you could get an engine block heater installed. You'll use more power off the grid but less fuel. Kind of a catch 22.
The sooner you can get your vehicle to normal operating temp the less fuel you will consume.
One other thing....don't use your defroster setting for longer than you need it. It runs your a/c to dehumidify. All vehicles do this. So if it's 30 degrees out and you have the defrosters on un-necessarily, you are running your a/c. Once your windows are defrosted switch it to floor or floor/vent. I also installed "in-channel" vent visors ao I can run with the windows cracked and not hamper my aerodynamics.
One other thing....don't use your defroster setting for longer than you need it. It runs your a/c to dehumidify. All vehicles do this.
Most, but not all. My VW doesn't, and that's one of the features I really like. It's great for melting ice off the windshield, or just providing diffused air rather than blowing air at face/feet -- though the VW also has a diffused vent that can be routed instead of the dash vents.
I wonder how hard it is to prevent the A/C from coming on with the defroster on most cars? I'd love to do that in my GMC.
A $2 toggle switch from Radio Shack and about 10 feet of 16 gauge wire should do it. Mount the switch to the bottom of your dash. Connect one end of the switch to a good ground. Cut the ground wire to the compressor clutch. Splice in your wire from the dash switch. When the switch is off the clutch will not activate.