How many mpg do you guys get in the winter? I live in upstate NY (Vestal), and the temp fluctuates anywhere from -8 to 35 degrees in the past couple of weeks. Since I filled up last wednesday, I've gone through 3/4 tank having driven only 120 miles. That averages out to about 12mpg, which is less than half of its rated gas mileage. I know you're suppose to get less mileage in the winter, like maybe 20mpg or so, but 12mpg seems ridiculously low. Heck my teg has the efficiency of a hummer!

Anyways, here's my driving habits if anyone cares to diagnose:
1) I always warm up my car 2-5 minutes.
2) My daily commute to and from campus is 1.7 miles each way (2 trips on average daily).
3) I never floor my car, I slowly accelerate and I'm not a delayed braker.
4) I stay +/- 5 miles of the speed limit always (45mph on the parkway to campus, 20-25mph limit on campus).
5) Most trips to campus, Walmart, errands are 5 miles or less.
6) The roads around here are faily inclined, reaching up to 45 degrees (think San Fran...almost).
7) I drive an automatic and always drive in D5 (normal).

My 95 LS has 70850 miles on it. Are there any parts I should be looking in to replace? Spark plug perhaps? A dirty muffler at fault? Dirty filters (air, oil and tranny filter just replaced)? Any other suggestions?

Thanks in advance!

 

Theoretically you should get more gas mileage in winter. Theoretically you would make more power, and at a lower RPM because of the colder, more dense, oxygen that is flowing into your engine. Consequently you wouldn't shove the gas pedal down to the floor as far as you normally would to accelerate at the "normal" rate that you normally would.

Of course, that's not how it works. We all go "Woo! My car makes more power! It feels fast again!" and floor it all over the place.

The short trips will eat your gas mileage, but I still wouldnt expect anything less than say 20mpg overall out of all of that.

Perhaps it's a combination of bad plugs, wires, and your short drives - warm ups - automatic transmission, and "winter" (if thats a factor as you seem to think so) all adding up to terrible fuel consumption.

 

..and winter fuel additives.

 

When I blame winter, I assume the warmup times, fuel additives, and "thinner fuel" (gasoline expands in summer when it's warmer, no?).

 

no. in the winter, the air is denser, therefore more fuel has to be supplied to match it. my driving style is basically the same all year round. actually, if anything, i'm more conservative in the winter due to icy roads and such.

the fuel comsumption in my RS is like clockwork. i can count on getting at least 40 miles LESS out of a tank in the winter. it even applies to when i've done 100% highway miles on a tank, winter vs. summer. and this like being at a constant 80mph, not mashing the throttle here and there.

i also don't think any alleged winter fuel additives can account for this difference.

 

I think you're getting pretty bad mileage because you are driving very short distances. Your car doesn't get a chance to get up to operating temperatures, especially in winter. Mileage will be worse in winter (this is normal), I should know, being in Canada. All my family's cars are like this, probably due to the fact that the car revs higher at idle trying to get to operating temps faster.

I suggest getting a block heater to warm up the car and turning it on a few hours before you need to drive in the morning. I also strongly suggest to drive it for 20 miles or so, once a week. This is to burn off the water and acids that accumulate in the oil and exhaust because you drive short distances or else you will prematurely rust out your exhaust system, ie muffler, pipes....

 

ah, i hadn't noticed that. frequent short trips will definitely make milage worse. i do disagree with the notion that the increased idle, to warm up the engine, results in worse milage. i don't think it happens long enough to make much of a difference.

 

maybe you just need a full tune up? :dunno:

 

Hmm.. I rarely get the chance to drive 20+ miles in one trip since I live so close to campus. At most, maybe 10-15 miles if I visit a neighboring city for errands. As for the idling, the time I spend idling till my car starts to warm is equivalent to about 50-75% of the time it takes for me to actually drive to school (1.7 miles away), so I would assume that accounts for an accountable amount of fuel consumption?
:driving:
My car acts weird. Last fillup, I only got ~150 miles off more than 3/4 tank. I filled up 2 days ago and since then got 60 miles out of it with barely a 1/4 tank. :dunno: