Gas mileage in my '03 OBW

[M. Baker]

I'm not "blaming" poor mileage on AWD, and I KNOW that the AWD is full-
time on my Outback. All I meant was that the AWD got a "workout" for
a few days there when we had slush and snow on the roads. As opposed
to driving on clear roads with no snow to 'plow through', so to
speak. I would guess that if I drove the entire tank of gas when we
were having a blizzard with snow piles everywhere that I'd have to go
thru, the engine/AWD would thus have to work harder than on impeded
roadways, and thus result in worse overall mpg.

Take a pill. Jeesh.

 

[M. Baker]

Unless they changed the meaning of AWD, your Subaru is always driving all
four wheels. So your statement below makes no sense. You are using AWD for
100% of your tank, period. Temperature will affect your mileage, as will
driving style. You don't have a part-time 4WD so stop blaming poor mileage
on AWD.

DS

I'm not "blaming" poor mileage on AWD, and I KNOW that the AWD is
full-
time on my Outback. All I meant was that the AWD got a "workout" for
a few days there when we had slush and snow on the roads. As opposed
to driving on clear, dry roads with no snow to 'plow through', so to
speak. I would guess that if I drove the entire tank of gas when we
were having a blizzard with 6+" of snow everywhere that I'd have to
go
thru, the engine & AWD would thus have to work harder than on
unimpeded, clear
roadways, and thus result in worse overall mpg.

Jeesh.

 

[B A R R Y]

I'm not "blaming" poor mileage on AWD, and I KNOW that the AWD is full-
time on my Outback. All I meant was that the AWD got a "workout" for
a few days there when we had slush and snow on the roads. As opposed
to driving on clear roads with no snow to 'plow through', so to
speak. I would guess that if I drove the entire tank of gas when we
were having a blizzard with snow piles everywhere that I'd have to go
thru, the engine/AWD would thus have to work harder than on impeded
roadways, and thus result in worse overall mpg.

You guess wrong.

 

[M. Baker]

Why? If "driving style", i.e. taking off fast, stomping on the
brakes, flooring it, would affect the mpg, why would winter weather
driving not affect it also? If the engine/AWD has to work harder to
get me thru snow or heavy slush than if the roads are clear, why would
that not affect it also?? One usually has to use a bit more gas pedal
to get thru that stuff than if the road is clear.

 

[Todd H.]

Why? If "driving style", i.e. taking off fast, stomping on the
brakes, flooring it, would affect the mpg, why would winter weather
driving not affect it also? If the engine/AWD has to work harder to
get me thru snow or heavy slush than if the roads are clear, why would
that not affect it also?? One usually has to use a bit more gas pedal
to get thru that stuff than if the road is clear.

You are correct. Such factors do affect gas mileage as it affects the
rolling resistance of the vehicle (anyone who has pushed a wagon
through mud vs dry bike path knows this) and how much work the engine
has to do to compensate.

AWD is certainly part of the reason mileage on our subies is
lackluster. There's a whole lot of transmission to keep moving with a
whole lot of fluid in it that cars with less functional transmissions
don't have to fight against. Like so many things, it's a tradeoff.

Not sure why the witch hunt seems to have been levied against you.
Seems sorta silly.

Best Regards,

 

[alf]

Hi,

Just fresh data from Chicago-Aspen-Chicago trip in various ambient
temperatures (from 20F o 45F) at speeds ranging from 45MPH to 85MPH. for
the record car (MT, regural Outback 2002, 100 miles on it) was started
over dozen times thru out the trip including four very cold mornings and
cold evenings.

The average fuel economy on that 2700 miles trip was 22.1MPG. The speed
seemed the major factor influencing it. There was very slow part of
500 miles (due to conditions - they even closed I80 west of Des Moines
so we had to take an alternate route) to drive about 45-50MPH - the
distance made on the single tank increased significantly.

Interestingly (I observer it before too), in spite of quite aggressive
driving on I70 in the Rocky Mountains, the car yielded very decent above
the average MPG (estimated to 24-25). I still can not understand why.


Regards, Andy

 

[B A R R Y]

Why? If "driving style", i.e. taking off fast, stomping on the
brakes, flooring it, would affect the mpg, why would winter weather
driving not affect it also?

Trying to nail it down to a single variable is pointless, because you
don't know so many other variables.

Did you log the temperature every time you drove? How about winds? Did
you travel exactly the same route each tank? Do you have a clear filler
neck, so that you know to stop at exactly the same level at each filling?

On a day where weather turned your 70 MPH commute into a 55 MPH commute,
you may have gotten better mileage that day. <G>

 

[Carl 1 Lucky Texan]

You are correct. Such factors do affect gas mileage as it affects the
rolling resistance of the vehicle (anyone who has pushed a wagon
through mud vs dry bike path knows this) and how much work the engine
has to do to compensate.

AWD is certainly part of the reason mileage on our subies is
lackluster. There's a whole lot of transmission to keep moving with a
whole lot of fluid in it that cars with less functional transmissions
don't have to fight against. Like so many things, it's a tradeoff.

Not sure why the witch hunt seems to have been levied against you.
Seems sorta silly.

Best Regards,

Yep.
I've read figures that indicate 'typical' 2WD drivelines present about
13% frictional loss. Our AWD about 20% loss. And there's the additional
weight. (maybe 200 lbs. ???)
Throw that in with winter driving - longer engine 'choke' conditions for
warmup, poorer road surface conditions, 'winter' formulated gas, and
maybe a coupla other factors.....

Carl

 

[Ed]

Yep.
I've read figures that indicate 'typical' 2WD drivelines present about
13% frictional loss. Our AWD about 20% loss. And there's the additional
weight. (maybe 200 lbs. ???)
Throw that in with winter driving - longer engine 'choke' conditions for
warmup, poorer road surface conditions, 'winter' formulated gas, and
maybe a coupla other factors.....

Carl

Like running the defroster which engages the A/C to dry the air.