Outback fuel consumption (AUS)

[hippo]

Well that was clever ... a post with no content. Sorry!

Running a 99 Outback Limited 2.5L A/T. Fuel consumption is around
12.5L/100km urban (22.5mpg) (country town, 10-20km trips) and 11L/100km
hwy (26mpg) keeping to posted limits and generally driving like a granny.
Absolute best has been 9.7-9.9L/100km (nearly 30mpg - so IMO still not
brilliant) over three consecutive tanks. It then dropped to current poor
figure. (This compares with 10.5 and 8.5 on a manual 91 Liberty wagon on
similar roads and service, driven more for enjoyment than with any real
regard for fuel consumption). OB drives beautifully but fuel figures seem
to be excessive for light driving usually with only one or two people.
Anyone got any ideas?

We have correct oil grade, new filters, new plugs, good leads, O2 sensor
is ok, tailpipe emissions perfect and no codes. I don't drive most cars
specifically for economy(!) but this is the first time ever I have
actually been unable to when trying! Figures are reasonably consistent
over nearly 5000km, regardless of fuel, including ULP with or without
ethanol and 98RON Premium, which gave the worst hwy figure to date
(9Km/L). So what's next? Track the fuelling through the rev range on a
dyno is about all I can think of! Or is this the best I should be
expecting? All helpful suggestions welcome. Thanks

 

[Coggo]

Hippo,

This may be of some interest - I am also in AUS.

I have a MY00 Forester GT, which was getting sluggish and using more fuel. I
was getting all services from the dealer as required, until the end of
warranty, then I went to my local mechanic (top man!). He used a product
made for/by Subaru to clean out the inlet manifolds - it's a spray pack
which is fed into the manifold somewhere, you take the car for a big thrash,
and it cleans all the gunk (oil from PCV, etc.) off the inlet passages. He
also used the recommended synthetic oil - both of which should have been
done by the dealer, but not done.

The result was miraculous!! The car regained all it's original great
acceleration, and fuel consumption improved. I don't have figures, but I get
about 80 -100 Km more per tank - using premium unleaded, well worthwhile!!

Might be worth a thought for your problem.

Regards

Dave

 

[hippo]

I have a MY00 Forester GT, which was getting sluggish and >using more fuel.
I was getting all services from the dealer as required, >until the end of

warranty, then I went to my local >mechanic (top man!). He used a product
made for/by Subaru >to clean out the inlet manifolds - it's a spray pack

which is fed into the manifold somewhere, you take the >car for a big

thrash, and it cleans all the gunk (oil >from PCV, etc.) off the inlet
passages. He also used the >recommended synthetic oil - both of which
should have been

done by the dealer, but not done.

Thanks very much. Food for thought. Spray has been done but not running
synth oil. Last change (not by me) was wrong weight so changed it after
about 2000km once I found out to see if any difference. Nothing to date.
Car's doing South Coast-Sydney & back every couple of weeks but maybe we
should run it harder for a while (i.e: drive for fun not economy) and
keep the synth in mind for the next oil change. Just out of interest,
which oil did you go for? Thanks again.

 

[Coggo]

My mechanic used Castrol R Synthetic 5W-30. I am in SE Qld - should be about
the same in your area.

Cheers

 

[hippo]

My mechanic used Castrol R Synthetic 5W-30. I am in SE >Qld - should be

about the same in your area.

Cool. Thanks. I'll try that on the next change.
Happy driving

 

[Losiho]

Well that was clever ... a post with no content. Sorry!

Running a 99 Outback Limited 2.5L A/T. Fuel consumption is around
12.5L/100km urban (22.5mpg) (country town, 10-20km trips) and 11L/100km
hwy (26mpg) keeping to posted limits and generally driving like a granny.
Absolute best has been 9.7-9.9L/100km (nearly 30mpg - so IMO still not
brilliant) over three consecutive tanks. It then dropped to current poor
figure. (This compares with 10.5 and 8.5 on a manual 91 Liberty wagon on
similar roads and service, driven more for enjoyment than with any real
regard for fuel consumption). OB drives beautifully but fuel figures seem
to be excessive for light driving usually with only one or two people.
Anyone got any ideas?

We have correct oil grade, new filters, new plugs, good leads, O2 sensor
is ok, tailpipe emissions perfect and no codes. I don't drive most cars
specifically for economy(!) but this is the first time ever I have
actually been unable to when trying! Figures are reasonably consistent
over nearly 5000km, regardless of fuel, including ULP with or without
ethanol and 98RON Premium, which gave the worst hwy figure to date
(9Km/L). So what's next? Track the fuelling through the rev range on a
dyno is about all I can think of! Or is this the best I should be
expecting? All helpful suggestions welcome. Thanks

I have the same car, same transmission (but mine is a GX, not a Ltd).
Currently have 85,000km.

I'm getting around 11.5L/100km. I either use BP Ultimate 98 or Caltex Vortex
95 (waiting for Vortex 98 to arrive in Victoria next year). I get slightly
better fuel economy with 98 octane, but the engine feels a little more
"sprightly" with Vortex. My best highway figures are 8.92L/100km using
Shell Optimax. The upper engine cleaner sounds like a good suggestion.

And btw, Castrol R 5w30 is NOT a synthetic.

 

[John O]

Running a 99 Outback Limited 2.5L A/T. Fuel consumption is around

12.5L/100km urban (22.5mpg) (country town, 10-20km trips) and 11L/100km
hwy (26mpg) keeping to posted limits and generally driving like a granny.
Absolute best has been 9.7-9.9L/100km (nearly 30mpg - so IMO still not

I have the same exact vehicle, and my mileage is about the same as yours.
Seems like I do get a little better numbers from mid-grade fuel. Keeping
tire pressures at the high end of normal and all equal with each other helps
a bit. Is your OB black? Maybe that's it. ;-)

-John O

 

[John Hannigan]

No helpful suggestions but I do feel kinda jealous at your consumption
figures. I took delivery a couple of days ago ( in Ireland ) of a new OB
2.5 with A/T and have so far put up around 400 miles. I have been quite
refined in my driving as the book seems to suggest taking it easy for the
first 1000 miles. A mixture of town and hills is averaging 24.9 MPG which
is well short of your best. No decent motorway driving yet but next weekend
......

Cheers
John

 

[Coggo]

Well, I have the oil container here, and it say "CASTROL R SYNTHETIC 5W30"
so I don't know what else I can say.

 

[Losiho]

Well, I have the oil container here, and it say "CASTROL R SYNTHETIC 5W30"
so I don't know what else I can say.

It's a Group 3 Hydrocracked oil, which in plain english means it's a highly
refined mineral oil. It's not a PAO or ester based synthetic, which
enthusiasts call "real" synthetic.

Welcome to the Castrol world of marketing

 

[hippo]

I have the same exact vehicle, and my mileage is about the same as yours.

Seems like I do get a little better numbers from mid-grade fuel. Keeping

tire pressures at the high end of normal and all equal with each other helps
a bit. Is your OB black? Maybe that's it. ;-)

Tyres are 36psi all round and evenly worn. Aligned ok

It's not black (liked that one) but water restrictions ensure a sort of
dirty brown with metallic maroon poking through here and there 9 days out
of 10. On the other one we take it 12kms to the car wash in town and then
drive back up a 300m dirt drive! Hmmmm .... Cheers & thanks

 

[Damon McMahon]

I have the same car, same transmission (but mine is a GX, not a Ltd).
Currently have 85,000km.

I'm getting around 11.5L/100km. I either use BP Ultimate 98 or Caltex Vortex
95 (waiting for Vortex 98 to arrive in Victoria next year). I get slightly
better fuel economy with 98 octane, but the engine feels a little more
"sprightly" with Vortex. My best highway figures are 8.92L/100km using
Shell Optimax. The upper engine cleaner sounds like a good suggestion.

And btw, Castrol R 5w30 is NOT a synthetic.

For the archives [as I have nothing useful to suggest for hippo] my
figures are about the same, i.e. 11.5 L/100 km urban and 10 L/100 km
rural, using PULP which I would estimate saves me up to 1 L/100 km in
urban travel, plus gives the engine better response at mid revs
(2500-3500 rpm) - and, of course, has lower emissions [at least, that's
how I justify to myself the extra $0.08 per litre!]

All this with an engine that's done almost 210,000 km and a clutch that
needs replacing!!