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am i getting bad fuel economy??
Posted: Wed Mar 17, 2010 12:41 am
by subie_1st_timer
just wondering if im getting bad fuel economy from my Gen2 MY98 liberty as i struggle to get 500km to a tank!
My daily commute to work is about 40km each way, 35 of those are on the motorway @ 110km/h.... so just thought id pop the question.
I only use BP ultimate fuel or a 98 octane and am on my 3rd tank since having the car and SLOWLY seem to be getting more km to a tank but still, i kinda hoped for a little more and most days been using the cruise control on the motorway too to help stretch it.
i havent looked up the tank capacity yet but im guessing its around 50lt, so 10lt/100km isnt that crash hot for a 4cyl doing mostly highway driving IMO.
I did read on a website that this model (with ej25 motor) gets 10.5lt/100km around town and 7.5lt/100km freeway... so im a little off the mark.... So can Anyone share some figures they getting please, curious to know... cheers
Posted: Wed Mar 17, 2010 12:52 am
by GOD
"am i getting bad fuel economy?? "
Hopefully this doesn't sound too impolite, but how the frack should I know? Go away and measure it.
Fill the fuel tank and zero the tripmeter. Drive. Next time you refuel after that, note how many km you've done, and how many litres of petrol it takes to completely fill the tank again. Calculate average fuel consumption. Repeat a few times. Then you might have something to talk about.
Dane.
Posted: Wed Mar 17, 2010 9:02 am
by RSR 555
Well.. how do we follow that.. Ummm my best advice would be have the car injectors cleaned, fuel filter changed and a compression check done. Then monitor it again. I'm guessing that your fuel economy isn't as good as when it was brand new but still can be better. Do you have an AWD model? because they will use more due to the drag of turning all 4 wheels. If you have a AWD auto model you can put a 10amp fuse in the FWD holder (under the bonnet) and drive around in 2WD while the weather is fine and dry.
Posted: Wed Mar 17, 2010 10:17 am
by steptoe
A new O2 sensor is always a good shot too as it is what leans the mix to correct. If it stuffs up things go rich as the default. Drive a 2.5 carefully as they have the potential power and fuel guzzle to go with power delivery.
litres per hundred kilometers is the expected measure
Posted: Wed Mar 17, 2010 10:59 am
by subie_1st_timer
GOD wrote:"am i getting bad fuel economy?? "
Hopefully this doesn't sound too impolite, but how the frack should I know? Go away and measure it.
Fill the fuel tank and zero the tripmeter. Drive. Next time you refuel after that, note how many km you've done, and how many litres of petrol it takes to completely fill the tank again. Calculate average fuel consumption. Repeat a few times. Then you might have something to talk about.
Dane.
what do you think i been doing Dane...main reason i asked wasnt for smart ass replies either, was to compare figures with other people and their vehicles... surely you could of figured that out, like you, without sounding impolite
RSR 555 wrote:Well.. how do we follow that.. Ummm my best advice would be have the car injectors cleaned, fuel filter changed and a compression check done. Then monitor it again. I'm guessing that your fuel economy isn't as good as when it was brand new but still can be better. Do you have an AWD model? because they will use more due to the drag of turning all 4 wheels. If you have a AWD auto model you can put a 10amp fuse in the FWD holder (under the bonnet) and drive around in 2WD while the weather is fine and dry.
yes my liberty is an AWD auto version... might try the 2wd idea and see how that goes and see if there is an improvement, thanks for the tip!!
the car is comming upto 150000km so have a major service planned for it which will include an injector clean and all filters changed.
cheers
Posted: Wed Mar 17, 2010 11:19 am
by RSR 555
subie_1st_timer wrote:yes my liberty is an AWD auto version... might try the 2wd idea and see how that goes and see if there is an improvement, thanks for the tip!!
the car is comming upto 150000km so have a major service planned for it which will include an injector clean and all filters changed.
cheers
No probs dude..
150,000kms service is not the big service and if you're getting it done by a Subaru Dealership or anyone for that matter, just make sure they give reports of what it was like before and after. I'm quiet suspicious of so called major services being done correctly
My advice is do most of it yourself (if your mechanically minded) and the things your not confident with, send the car to people that specialize in that area.. i.e. EFI specialists
Hope this helps

Posted: Wed Mar 17, 2010 12:33 pm
by Alex
i have a gen3 2.0l AWD and was getting pretty bad economy for a while..ie, 460km to a 47l fill.
went to bp ultimate which increase to about 530-540km to a 47l fill, but i use to get these figures with just bog 91 unleaded.
I have just recently(like 2 days ago) done an upper engine clean and injector clean. Along with new airfilter. Yet to do fuel filter. Also checked and re-inflated all my tyres cos they all had 30psi in them.
Will let you know the results when i get them.
But i do however have a heavy foot and do a fair bit of commuting in traffic. Also i have my headlights and foglights on 95% of the time (yes im a wanker) along with a very large power draining stereo which does make a fair difference.
alex
Posted: Thu Mar 18, 2010 5:37 pm
by Damned67
Not to be a smart ass, but here's what you need to do:
Fill up the tank.
Zero the trip meter.
Drive.
Fill up the tank again.
Make a careful note of the k's travelled and the fuel required to top the tank off again. I write it on the receipt and keep the receipt.
Do this a few times so that you have a really good idea of what you're actually using per km.
I've been keeping records of mine, and what I've changed since I bought it.
I've been meaning to throw up a post regarding it.
(it's also a '98 Outback).....
I'll sort out my last lot of records and post it up, but I started out at about 11.5L/100, and am now down to around 8.5l/100 (I think?).