Cold Weather Short Trip Driving

[Shel_B]

Filled up the Camry this morning and, sad to say, got the worst mileage EVER with this car. I averaged 17.8 mpg compared to the usual 21-22 mpg around town. The difference was that there was absolutely no freeway driving, the weather for the last month has been cold-ish, and all my trips were short ... nothing over 6 miles.

Many here will be familiar with this type of situation, but I mention it because there are also many folks who are concerned when their mileage drops during the colder months, or their driving style changes to encompass more short trips. I believe there may also be "winter gas" here in California that also has a deleterious effect on mileage.

Although I'm no novice to this situation, I was a bit surprised to the extent of the mileage drop.

 

[supton]

Cold start penalty is a big one.

But on the flip side, are you really using that much gas? Per mile it sounds awful--but on a time basis, is it? For example, sometimes I get great mpg--but in doing so, I'm filling up multiple times in the day (long road trip). Which costs more? Filling up once a month while getting lousy mpg, or filling up daily while getting great mpg?

Sometimes one has to look at the metric from a different perspective. Instead of a per mile cost basis, sometimes a per time unit basis may shed light.

 

[doublebase]

Yeah, I definitely notice a Mileage drop when the temperatures drop below 35 degrees, and especially if I’m doing short trips. The combination of winter gas, and the computer adjusting to air being more dense adds to fuel mileage dropping. But as soon as the temps creep back up my mileage goes back up too. Short trips don’t help either, as the cold starts lead to more fuel dumping in those cylinders.

 

[TmanP]

That's pretty in line with what I'd have guessed assuming some heavier traffic and no trips over 6 miles; my worst tank for the '12 with the same powertrain as yours is 21mpg or so, but at the depth of the midwest winter (though not severely short-tripped). Most cars seem to struggle to do well in this use case (with hybrids being the notable exception); given the way I drive I'm much more interested in highway MPG. With this car, I've not noticed any significant reduction due to winter gas as I can still do just as well on the highway in winter (tanks of 36-39) - the biggest reduction for my driving comes with warming up the car and short-tripping it in the winter.

 

[Quattro Pete]

Cold Weather Short Trip Driving

Define 'cold'.

For those of us living up north, when the temps are in single digits, it takes even longer for the engine to warm up during winter, so fuel economy takes an even bigger hit.

 

[Shel_B]

Define 'cold'.

For those of us living up north, when the temps are in single digits, it takes even longer for the engine to warm up during winter, so fuel economy takes an even bigger hit.

38-deg - 42-deg when leaving the parking lot, however, there have been times when the temp has been lower during the night, for example, this morning the temp was 42-deg when leaving the lot but a few hours earlier it was around freezing, and there was ice on the car's windows. I've not encountered freezing temps - and certainly not single-digit temps - here in the Bay Area in years, probably at least a couple of decades.

 

[Duffyjr]

That's quite a drop for nothing under freezing, I usually don't notice that much until it gets much colder and that includes 5-10 minutes warm up time.

 

[tmorris1]

38-deg - 42-deg when leaving the parking lot, however, there have been times when the temp has been lower during the night, for example, this morning the temp was 42-deg when leaving the lot but a few hours earlier it was around freezing, and there was ice on the car's windows. I've not encountered freezing temps - and certainly not single-digit temps - here in the Bay Area in years, probably at least a couple of decades.

That would be sweatshirt weather around here. What you are seeing is normal. My mileage on my Focus that I use for work commuting drops to about 27mpg in the winter and about 32-33 in the summer driving the same road with minimal traffic.

 

[TmanP]

Also, if this tank is a particular outlier, there's a chance that the station's pump, this time, filled "extra full" (went an extra gallon or so before stopping), or that the previous fill had the opposite happen (the pump you used the time prior to this fill might've cut off a gallon or so early). I've noticed a few pumps do this over the years, and this "heavy full" should lead to the next tank's MPG being much better than expected. It's not necessarily too likely but worth keeping an eye out for.

 

[Shel_B]

That's quite a drop for nothing under freezing, I usually don't notice that much until it gets much colder and that includes 5-10 minutes warm up time.

This past month or so I was going up into the hills more often than in the past, and I'm sure that helped contribute to the mileage drop.

 

[Shel_B]

Also, if this tank is a particular outlier, there's a chance that the station's pump, this time, filled "extra full" (went an extra gallon or so before stopping), or that the previous fill had the opposite happen (the pump you used the time prior to this fill might've cut off a gallon or so early). I've noticed a few pumps do this over the years, and this "heavy full" should lead to the next tank's MPG being much better than expected. It's not necessarily too likely but worth keeping an eye out for.

I always fill at the same two pumps and give an extra squeeze on the nozzle when the pump clicks off. I think my fills are pretty even from one to the next, but hey, I'm just a human ... <LOL> You make a good point, though.

 

[Duffyjr]

I always fill at the same two pumps and give an extra squeeze on the nozzle when the pump clicks off. I think my fills are pretty even from one to the next, but hey, I'm just a human ... <LOL> You make a good point, though.

I never try to put in more after it clicks, I've witnessed to many people soaked in gas from doing that, be careful.

 

[totegoat]

I use lower gears on short runs to help the engine get up to temp.

 

[PimTac]

The short tripping is contributing to the drop in fuel economy , not those mildly cold temperatures.

And overfilling the fuel tank will lead to other issues. I wouldn’t do it.

 

[ad244]

I never try to put in more after it clicks, I've witnessed to many people soaked in gas from doing that, be careful.

I live dangerously

 

[supton]

I go to the first click. After 100k it'll average out any error in mpg calculations.

 

[Jetronic]

5 clicks here. Dangerous is my middle name...

 

[Shel_B]

Cold start penalty is a big one.

But on the flip side, are you really using that much gas? Per mile it sounds awful--but on a time basis, is it? For example, sometimes I get great mpg--but in doing so, I'm filling up multiple times in the day (long road trip). Which costs more? Filling up once a month while getting lousy mpg, or filling up daily while getting great mpg?

Sometimes one has to look at the metric from a different perspective. Instead of a per mile cost basis, sometimes a per time unit basis may shed light.

For the month I've used a scosh more than 10-gallons of Costco's finest. That.s less than half what I've been using. So, from a $ & ¢ perspective, I'm fine. The past 30 days I've used the car for only 186 miles, I'm usually closer to 100 miles per week.

 

[Shel_B]

I use lower gears on short runs to help the engine get up to temp.

I'm always around town in 3rd or 4th gears. That keeps the revs in the 1500 - 2000 rpm range. No lugging, trans doesn't hunt for the "correct" gear. It might help bring the engine up to a higher temp, hard to say.

 

[dareo]

Maybe you will feel better knowing i just filled a half tank in my new to me 05 Escalade. Its parked outside, warmed up sometimes if snowy, driven 5 miles each way with lots of stopping/traffic. I also idled it a lot changing fluids and such. 8.99 MPG hand calculated. Cut out the maintenance running and I might get to 10!