In the past few weeks my gas mileage has decreased considerably.
The car seems to be running well.

But the outside temps have also decreased.
Would cold weather cause the mpg to go down on long trips?

I take the same trip every week.
112 miles each way.
Same route.
Same mph (72) with cruise on.

It has gone down from 26-27 mpg to 21-22 mpg.

Thanks.
Pat

Pat,

You might want to check/change your fuel filter for starters. Maybe some others will chime in with some better advice.

Don

how have winds been around you that will seriously effect your MPG. Fuel filter can also cause restriction as can the air filter. But i wouldnt worry too much unless it continues for a while

Do you let your car warm up in the morning now that its colder out? That might be the reason that you dont get as much miles to the tank.

Good point you made MYCADDY. Maybe you(Pat) should reset your computer each way on each trip to get an more accurate MPG result. Couldn't hurt to check the air/fuel filters as well. You may be killing your MPG by letting the car warm up in those below zero temps you have had lately.

Don

i'm with dead sled on the wind issue. it's been blowing really hard for last few days and my mpg is lot lower than before.

I suppose that is possible.
I will check it again next weekend.

Pat

Tire pressure?
I remember reading that the colder it is, the lower your tire pressure becomes.

Pat,
That's a substantial change in MPG. A clogged air filter COULD account for this. Unfortunately, so could a number of other items.
If the MPG doesn't rebound, I'd take a look at tune-up parts such as plugs, wires, or possibly even an O2 sensor failure.

could it be that the gas stations in your area use winter fuel formulas? I've noticed here in Pennsylvania when the winter formulation gas comes around my mileage drops a bit - just something to consider if you live in an area where that comes into play.
Also - with the recent fuel shortages it could be that the fuel in your area is coming from another part of the country where the formulation is different - which could impact your mileage.

Steve

Colder temps = lower tire pressures = lower mpg. Check pressure.

Colder climates = winter fuel mixtures = lower mpg. Not much you can do about this except move someplace warmer.

The colder it gets, the less complete the atomization of fuel in the combustion chamber. This is why the colder climates get the winter mix fuel - to help the atomization. If you live in the midwest like me, it can be 65 F one day and 25 F the following night. Keep an eye on tire pressure as a result.

All said, I'd expect about a 10% decrease in fuel economy during peak winter months versus peak summer months.