350km's out of a tank...damnnn

XR6_4EVA · 18-12-2010, 12:13 PM

Hey guys i went on a drive up to sail and back and on highway roads i think i managed 400km's from a full tank, thats damn terrible!

What are possible causes outside the obvious, ive replaced plugs, leads, coils, air filter, cleaned T/B, did a test on my 02 sensor, still reading correct.

Why!!!

Mr Hardware · 18-12-2010, 12:48 PM

driving style. i bet i could hop in your car, do the same drive and get an extra 100ks out of the tank.

b2tf · 18-12-2010, 02:02 PM

Quote:

Originally Posted by Mr Hardware

driving style. i bet i could hop in your car, do the same drive and get an extra 100ks out of the tank.

Seeing as you're so damn wonderful, drive yourself down here (it's about 1000km so you should probably do it in 3/4 tank?) and come and drive my ute while I go drive your awesome Series I (that apparently is sooooooo much better than series II/III models) and kick myself for buying an XR8 over a series I ex cab. Pull your head in and give the opinionated 'i am so right' replies a rest.

XR64EVA, is your battery voltage ok or is it on the low side? My fuel consumption changes a lot depending on how crap my battery is and youve covered everything else I would have suggested.

Mr Hardware · 19-12-2010, 12:44 PM

Quote:

Originally Posted by b2tf

Seeing as you're so damn wonderful, drive yourself down here (it's about 1000km so you should probably do it in 3/4 tank?) and come and drive my ute while I go drive your awesome Series I (that apparently is sooooooo much better than series II/III models) and kick myself for buying an XR8 over a series I ex cab. Pull your head in and give the opinionated 'i am so right' replies a rest.

Settle down kiddo!

POELWYK · 18-12-2010, 01:36 PM

dam thats better then mine im lucky to get that ourta my tank (worked 6 though)

Road Games · 18-12-2010, 02:23 PM

Quote:

Originally Posted by XR6_4EVA

Hey guys i went on a drive up to sail and back and on highway roads i think i managed 400km's from a full tank, thats damn terrible!

What are possible causes outside the obvious, ive replaced plugs, leads, coils, air filter, cleaned T/B, did a test on my 02 sensor, still reading correct.

Why!!!

How is your "Hi -flow cat" ? You havn't bashed it on a speed bump by chance ??
Unless you are carrying around 400kgs of Doof Doof there appears to be a more sinister prob lurking .....

I can PM you my car specs and the economy i achieve..
Daz..x..

Donny · 18-12-2010, 02:25 PM

Iv not done a full tank run in my 220 manual XR8 yet, but going by the DTE readings and my driving style I should get around 400klms out of a tank in mine... Thats averaging around 60/40 split being 60% round town, the rest at highway cruising speeds..
Being Iv only had the car a short time, Iv not really tried to drive it too economically as Im really enjoying radio Weezor too much, but Iv noticed during highway cruising, the economy is significantly better.. Running on the highway sees the DTE rise to longer as Im going..

The Monty · 18-12-2010, 02:34 PM

With the ol blue au I had (cam, 3.9's, 3k stall, ported head, etc etc etc) I still used to be able to get 9.2L/100km on the highway. It could be your driving style, or you could have a leaky injector, peirced fuel line, blocked cat, etc etc.

Road Games · 18-12-2010, 02:46 PM

Didn't even think of that

Well done Josh , check all fuel lines around tank and filter..... Maybe the new fuel filter ( if you replaced it as well )cross threaded and is leaking .. common prob for Z373's if the mechanic doesn't know what they are doing

mik · 18-12-2010, 04:01 PM

that sounds pretty crappy mileage, my car is basiclly a carbon copy of yours except 2 series, on a highway run in good conditions driving gently i would be expecting 700 + k`s to the tank(possibly more), obviousely in hilly twisty roads or pushing a head wind its gonna be a bit less, are you sure your consumption figures are accurate?

private9 · 18-12-2010, 04:33 PM

Was that purely freeway use, or was there combined driving in that?

I've had several AU 6s over the years and have rarely seen better than high 300s with maybe 40/60 combined (hwy/city)

Day-mow · 18-12-2010, 04:41 PM

What fuel are you running?

**GasoLane** · 18-12-2010, 04:49 PM

Quote:

Originally Posted by XR6_4EVA

Hey guys i went on a drive up to sail and back

Sail the yacht or SALE the town

XR6_4EVA · 18-12-2010, 05:57 PM

You guys mentioned the cat.....my hi flow used to rattle so an exhaust guy grabbed multi grips and clamped the cat closed a bit to stop the rattle...possible problem?

galaxy xr8 · 18-12-2010, 10:03 PM

Quote:

Originally Posted by XR6_4EVA

You guys mentioned the cat.....my hi flow used to rattle so an exhaust guy grabbed multi grips and clamped the cat closed a bit to stop the rattle...possible problem?

Does it seem slugish and poor on power ?.

sneaky · 18-12-2010, 06:24 PM

would low tyre pressure make that much difference?

i gave my au3 sr a run up the coast a year or 2 ago and the fuel economy was crap all the way there (5 hours) and around town. so i checked the tyres a few time. more crapness on the way home. found it to be a dirty air filter (but you already changed yours)

The Monty · 19-12-2010, 12:37 AM

Ahahaha, its rattling as its core is loose. Ditch it and put a new one in.

**Stav** · 19-12-2010, 09:10 AM

Get a new

and then look at your map sensor

XR6_4EVA · 19-12-2010, 11:29 AM

ill do that this week! cheers guys.

XR6_4EVA · 19-12-2010, 01:20 PM

with all due respect about the driving style issue, i got 400km's out of highway km's to sale and back... ever since cops speed detection equipment has gotten better im to scared to exceed the limit.

au11futura · 19-12-2010, 03:33 PM

mine gets 870 to a tank highway, and about 510 city, but i unpluged the bat a few days ago and i gotte re-train the thing again it took two months to train it the first time...

Beer Baron · 19-12-2010, 07:20 PM

My series 2 SR gets about 470km around town and about 800km on the highway.

WMD351 · 19-12-2010, 07:38 PM

Bad kitty cat, I'd also check the mufflers while you're under there.

au11futura · 20-12-2010, 09:32 PM

cat converter....

Juzman · 21-12-2010, 02:08 AM

I get 350-450 from a full tank with about 50% highway/city from my s2...

350 is pretty normal for city driving... isn't it?

Ride · 21-12-2010, 10:48 PM

Quote:

Originally Posted by Juzman

I get 350-450 from a full tank with about 50% highway/city from my s2...

350 is pretty normal for city driving... isn't it?

I get that from my 5.6L with twin 2.5" exhaust, would be expecting better if yours is an I6

LukeyST · 22-12-2010, 10:15 AM

XR6_4EVA, what sort of km's did you used to get from a tank before things started going downhill? Just thought we could compare our cars as they are very similar besides mine being manual. At the moment i can get 800+ kms on hwy and about 600-650 on 50/50 split of country and city driving.

I have an 'opened' airbox and x-force extractors on my ST, the rest of the system is factory but i will have a hi-flow cat and redback bolt on system installed in the next week or so, im interested to see what it will do to my economy.

Good luck with getting your car sorted too!

XR6_4EVA · 23-12-2010, 10:56 AM

Quote:

Originally Posted by LukeyST

XR6_4EVA, what sort of km's did you used to get from a tank before things started going downhill? Just thought we could compare our cars as they are very similar besides mine being manual. At the moment i can get 800+ kms on hwy and about 600-650 on 50/50 split of country and city driving.

I have an 'opened' airbox and x-force extractors on my ST, the rest of the system is factory but i will have a hi-flow cat and redback bolt on system installed in the next week or so, im interested to see what it will do to my economy.

Good luck with getting your car sorted too!

I used to be able to get around 600kms quite easily, not achievable anymore. I have pacey extractors, red back high flow cat (collapsed) and 2 1/4 red back exhaust system with rear muffler, and a KnN air filter with XR8 snorkel.

Just gotta replace that cat and o2 sensor, reset the ECU and go from there.

LukeyST · 23-12-2010, 11:02 AM

Quote:

Originally Posted by XR6_4EVA

I used to be able to get around 600kms quite easily, not achievable anymore. I have pacey extractors, red back high flow cat (collapsed) and 2 1/4 red back exhaust system with rear muffler, and a KnN air filter with XR8 snorkel.

Just gotta replace that cat and o2 sensor, reset the ECU and go from there.

Yeh fair enough, why didn't you get the 2.5" cat-back? Or is that a typo.

Our intakes and exhausts will be quite comparable once i get my exhaust on.

Hopefully the new cat and o2 will do the trick!

XR6_4EVA · 25-12-2010, 06:25 PM

Quote:

Originally Posted by LukeyST

Yeh fair enough, why didn't you get the 2.5" cat-back? Or is that a typo.

Our intakes and exhausts will be quite comparable once i get my exhaust on.

Hopefully the new cat and o2 will do the trick!

I had the chance to use a friends exhaust place for a whole day trying on different mufflers and exhausts, i found the 2 and a 1/4 sounded awesome without drone, even though its an auto if you hold the gear at 4000 rpm it sounds nuts. Besides from the many exhaust size threads on these forums ive decided that 2 and a 1/4 is sufficient for the big six with intake and extractors...im not going to do cam shaft or head work.