Fuel usage ???? bad ????

[Heylin]

2004 Legacy GT-B with PBMS reflash and Subtech Frontpipe, running 98.

Does 350kms on 60L (17.1L per 100km) 300kms of that all town driving ?.

Misses drives about 2 km to work each morning and 3 km home after picking up baby. Weekends its just used for short trips 5km between home and supermarket etc.

I know thats bad but we try to do a good 2 hour open road trip every month.

Cold weather combined with 3 weeks of short trips, sitting in traffic idling would make it drink the fuel ???

[GC8E2DD]

Wow, that is huge. Does your car have the ECO toggle? I assume all the pre-SI-Drive GTs do. Daily driving around town my wife averages about 10l / 100km.

[Heylin]

 GC8E2DD said:

Wow, that is huge. Does your car have the ECO toggle? I assume all the pre-SI-Drive GTs do. Daily driving around town my wife averages about 10l / 100km.

Nah no ECO mode on it.

Best I got since retune was 14.3L based on 70% open road and 30% town

Best prior to tuning was 11L based on 90% open road and 10% town

100% town prior to tuning was about 14-15L

So based on this tank it seems to be using about 3L more per 100 km than before, and it doesnt really get driven hard as baby is usually on board.

Mabey the warm up enrich is set high, ot the acell pump\enrich value is high, unsure what variables are settable in the stock ECU.

Id be happy with 400 kms off a tank for town driving.

[Joker]

OR

running a tad rich, was towing trailer for those figures though

[kiwisurf]

O2 sensor???

[Heylin]

 kiwisurf said:

O2 sensor???

Nope no error codes and also put in a new AFR sensor when we got the car.

Only has 68,000kms on it.

[Marky]

Jebus, I get that sort of mileage at Ruapuna! Haha

If you were a real bogan type, flooring it everywhere then sure that's believeable, but for a normal person driving at baby-in-back speeds that's pretty severe.

For arguments sake my last tank got me 480km 90% around town and topped up 53L, that was the BG including some snownuts and wife has a lead foot, BH gets similar so far.

THAT SAID - I had an airtrek turbo for a while and that got similar mileage. Had a big exhaust, reflash and was running upwards of 20psi, and we'd be absolutely stoked to hit 400km on a tank of gas. Had a real high stall converter in it so you just had to breathe on the pedal to get it on boost, I'd still have it but for the running cost, so many LOLs.

[Heylin]

God I do like the extra power, but I may get it flashed back to stock if I keep getting economy like that. Might talk to PBMS, perhaps a matter of leaning it up a bit more ?

[paulngui]

How much do you think is due to front pipe and how much due to the tune? Do exhaust mods affect fuel economy much in general? 17L/100km if definitely concerning :-\

[Dave88]

Mate take it back and get them to check it. My 06 legacy with full exhaust bigger top mount and host of other things with 200 kw atw still did 550km around town and heaps more on open road with same fuel tank

[sultan]

The only thing that is really relevant is your usage. The poor car is living its life on a cold engine. That's the down side of living so close to work. Permanently driving around in a state of engine warm up doesn't surprise me of your consumption. I am in the same boat. My commodore gets 7-8L/100km on open road but i average 22+ driving only 3km to work and then back

[Joker]

1.1km to work for me

[94 Leone]

My bh hasnt used any fuel in two years... Hasnt been started but still counts... Kinda

[JWDRPN]

i have the same problem as you ryt now and its incredibly fustrating

my mechanic wants to check my cam timing..but also it could be an airleak or faulty coil etc etc

[94 Leone]

Yeah, the car wasn't running quite right after months of work on it, now that I think about it i'm gonna say it was the o2 sensor that dad has knack for breaking them :I anywho after needless spending on ideas i didnt use, I'm nearly there- however I'm away for the next ten days so nothing's getting done

[Pappu1]

mostly after a tune i have only seen better fuel use....

maybe a sh!t tune...??

[Heylin]

 pappu said:

mostly after a tune i have only seen better fuel use....

maybe a sh!t tune...??

Tune has been the only major thing done to car since the good factory economy readings i was getting.

Then again the weather has also been substantially colder as well, so could well be the car being in its warm up map most of the time.

Might give it another tank and try get some longer trips in it to see what it can do.

Was tuned at PBMS and they spent alot of time on it, pretty Sure Gary there knows his stuff, lots of good

tunes come out of PBMS.

[Pappu1]

were u doing the same soet of drive pre and post tune?

[Heylin]

 pappu said:

were u doing the same soet of drive pre and post tune?

Yeah pretty much, baby on board 99% of the time so cant really use the go pedal around town.

Drive back from Puke worked out to be 14.3L per 100 km based on 70% open road and 30% town.

Yet to do a 100% open road trip.

Suspect it will be 12L per 100 on open road and 17L per 100 for town. Go pedal driving may hit 18-20L per hundred kms

[clintondane]

 JoKer said:

1.1km to work for me

Walk you lazy biatch

Lol.

[Dave88]

Pre tune what were your fuel usage stats roughly?

[Dave88]

Just answered my own question... If you were doing 11L/100k pre tune with 90% open road driving that's not too great either for a legacy gt, like I said earlier mine had 200kw atw and open road driving I could still get 8.5-9.5L/100k so I'd say you had an issue prior to tune and tune has just accelerated it and made it worse or you have a lead foot. Take it back to Garry capper as he will have some sort of satisfaction thing with his work

[Heylin]

 Dave88 said:

Just answered my own question... If you were doing 11L/100k pre tune with 90% open road driving that's not too great either for a legacy gt, like I said earlier mine had 200kw atw and open road driving I could still get 8.5-9.5L/100k so I'd say you had an issue prior to tune and tune has just accelerated it and made it worse or you have a lead foot. Take it back to Garry capper as he will have some sort of satisfaction thing with his work

filled up today, came out at 17.6L per 100km, thats 100% town driving.

gonna try one or 2 more tanks to get an average, and also an open road trip.

[Pappu1]

do a quick log to see if its running really rich on cruise

and if its jumping to open loop rich very quickly

also, have u maintained the car well

i mean after the tune there has been no issues with the car?

have u got any leaks etc may

of installed a bov etc?

[Heylin]

 SP00N said:

do a quick log to see if its running really rich on cruise

and if its jumping to open loop rich very quickly

also, have u maintained the car well

i mean after the tune there has been no issues with the car?

have u got any leaks etc may

of installed a bov etc?

this is the second time the car has been filled up since the tune, no other mods or issues with the car. we got at 64,000 kms and I did all the maintainence, new AFR sensor, oil, diff fluids, transmission, filters etc etc.

based on the type of use its had in the last 3 weeks (short trips and cold weather) im going to say my gut feel is a rich warmup routine, combined possibly with a high acel pump\enrich value.