fuel economy

[Ryan]

I was recently reading a spec sheet on my 97 legacy GT when I was shocked
and dismayed to find that it has a factory fuel efficiency of 9.8 l/100Km,
my current fuel consumption is at least 14.2 L/100Km, and sure, it's not
like it's brand new anymore but surely there must be something wrong for it
to be that far off standard. Fuel prices in NZ have just been hiked up once
again so I'm desperatly in search of someone who knows the leading cause of
fuel inefficencies in subarus. Have I come to the right place?

Any help would be appreciated

Ryan

 

[Edward Hayes]

Check the O2 sensor

 

[TG]

Probably dirty injectors...O2 sensor would also do this but would likely
throw a code if it was that bad. Temp senser might also be making it rich.
TG

 

[Ryan]

Cheers for your help
I'm having a fuel air ratio and boost guage installed next week, hopfully
that should help me to start diagnosing problems, do you think it is worth
also installing an intercooler outlet temp guage??
Actually I put a injector cleaner through it about a month ago and found
some marginal gains, but I think it was just a one off case because this
gain has dissappeared, I have had the subaru service center run their
diagnostic equipment through it about 5000km ago with no errors so i can
only assume the sensors are OK. would spark plugs make a difference??

Ryan

 

[Bruce Hoult]

I was recently reading a spec sheet on my 97 legacy GT when I was shocked
and dismayed to find that it has a factory fuel efficiency of 9.8 l/100Km,
my current fuel consumption is at least 14.2 L/100Km, and sure, it's not
like it's brand new anymore but surely there must be something wrong for it
to be that far off standard.

I agree.

MIne's a '95 Legacy 250T (2.5L auto wagon) and gets anywhere from 9
L/100km on a gentle trip to 11 L/100km on a total thrash. Average is
right around 10.

I used a friend's Legacy GT (2.0 twin turbo manual wagon) for a while
and even with quite a bit of "lets see what this baby will do" still
managed to do no worse than 11 L/100km.

I don't know what the problem might be though, assuming yhou've checked
obvious things such as tyre pressures and alignment.

-- Bruce

 

[Yousuf Khan]

Cheers for your help
I'm having a fuel air ratio and boost guage installed next week, hopfully
that should help me to start diagnosing problems, do you think it is worth
also installing an intercooler outlet temp guage??
Actually I put a injector cleaner through it about a month ago and found
some marginal gains, but I think it was just a one off case because this
gain has dissappeared, I have had the subaru service center run their
diagnostic equipment through it about 5000km ago with no errors so i can
only assume the sensors are OK. would spark plugs make a difference??

Ryan

Are the Legacy GT's turbocharged in NZ? Over here in NA, they use a 2.5L
normally aspirated engine.

Yousuf Khan

 

[Bruce Hoult]

Are the Legacy GT's turbocharged in NZ? Over here in NA, they use a 2.5L
normally aspirated engine.

Yes. In Japan/NZ/Aus/UK, a Legacy with "GT" label is a 2.0L turbo,
single or twin depending on the year.

-- Bruce

 

[Yousuf Khan]

Yes. In Japan/NZ/Aus/UK, a Legacy with "GT" label is a 2.0L turbo,
single or twin depending on the year.

Is that the 227HP 2.0L turbo that you get in the WRX's here in NA?

Yousuf Khan

 

[Bruce Hoult]

Is that the 227HP 2.0L turbo that you get in the WRX's here in NA?

More in the 260 - 280 HP range, depending on year, I think.

-- Bruce

 

[trev]

Is that the 227HP 2.0L turbo that you get in the WRX's here in NA?

Yousuf Khan

Depending on the year the TT 2.0 GT & GTBS are 250,260 or 280hp