fuel economy

[surfstagea]

in light of a recent trip in my staj, i thought i would see if anyone else has experienced crazy fuel economy figures at times.

normally i get 12 liters per hundred k's on average. this is ok, consisting of a mixture of city and country driving.

driving at 130 ish in the middle of a hot day with the ac on (for about 300 k's out of my 650k total trip), i took my average! economy for my trip up to 20 liters per hundred!!!

that seems a little excesive... anybody care to comment? perhaps the ac + 130 = bad fuel economy?? well... obviously, but that bad?

(12 psi boost, exaust & pod)

[Terminal]

I think for any car, over 100 is going into bad fuel economy, especially for a 4 speed auto.

[jake32]

in light of a recent trip in my staj, i thought i would see if anyone else has experienced crazy fuel economy figures at times.

normally i get 12 liters per hundred k's on average. this is ok, consisting of a mixture of city and country driving.

driving at 130 ish in the middle of a hot day with the ac on (for about 300 k's out of my 650k total trip), i took my average! economy for my trip up to 20 liters per hundred!!!

that seems a little excesive... anybody care to comment? perhaps the ac + 130 = bad fuel economy?? well... obviously, but that bad?  

(12 psi boost, exaust & pod)

260rs got 380k`s on 65litres ..air con 3 passengers..i thought that was pretty horrid ...reasonably normal driving..getting injectors ultrasoniced to see if that improves anything but realise 2.6 on any boost(120kph+) will suck hard

yours works out at about 325 per 65ltr ..sounds like a bit much

[Jay95R33]

I used to get about 330 per tank when I worked 5 mins from home. It pretty much only drove on cold start so used heaps of fuel Now that I work 30mins away, about 50% highway, 50% around town driving I get 450...

Heavy turbo car with an auto box makes it thirsty

J

[Terminal]

I only get about 360 at the moment, but i love to drive, so i give it a bit most of the time. i have to stop this however if i want a car in a year.

[tigerleo62]

I get a bit over 14L per 100Ks of mostly city/suburban driving with the odd trip up the freeway... I got about an extra 80km out of tank once by driving very sedately with that tank of fuel, but it wasn't much fun. I really notice the decreased fuel enconomy if I plant the right foot due to idiot provoked road-rage.

Car is more economical at freeway speeds, but I haven't had a chance for a drive out of the suburbs to find out what it's like over 100ks for extended periods.

[burkey22]

I find that if during long trips I stick to 100-110 I'll get reasonable economy, however if I drive at 120 or over fuel ecenomy goes out the window due to the boost going from next to nothing to 5psi I guess. I get where I'm going quicker though.

[surfstagea]

ahhh balancing practicality with performance...... well i guess there's only one way to find out. do another trip and keep it to 110 with no ac, see what happens?? i guess i was just shocked that an extra 20 k's an hour plus an ac sent my fuel economy through the roof! i kept an eye on the boost guage too, and pritty much kept it off boost the whole way. (long trip, didnt want to cost a fortune). cheers guys.

[BoyWhoCriedWolf]

Your fuel usage will rise dramatically with speed (we have no speed limits up here so i do know). Stagea's are bloody thirsty and nothing is going to change that, apart from an safc or the like. I get around 400km to the tank, i give a bit around town too. I am running 13psi and the fuel economy hasnt changed much from running the factory boost. Stageas run very rich from the start. I pay around $1.10 per litre of premium, what are you guys paying?

Ken

[Terminal]

An interesting fact my Brother in law told me (mechanic) that driving with AC on is more efficient than with the windows down on long, highspeed trips. so just keep that in mind when testing to see if better fuel economy without AC, don't wind the window down

[surfstagea]

yes, i also get about 400 k's (not quite full, about 50 liters). have also heard that they run quite rich, although, when i posted a dyno graph up a few months ago i was told that it was lean? dunno bout that one. cant say ive had any experience with safc or alike. in adelaide i am using bp ultimate, and paying between $1.05 and $1.15.

terminal, i recon that your brother in law would be right. i heard a story a while ago about driving with bikes on the roof, if its a long journey its actually cheaper to send them seperately by courier!! hehe.

[Lone]

I get around 400kms to a tank just driving aroudn town and thats getting under it a little every now and again..

Id expect 500km+ for highway driving, Ill find out soon..

Also I might add in that when testing new cars they used to do it on a circuit with windows up and no air con on and at constant 80km/h from what I remember. The testers then complianed how hot it was of course and they now supposly test them on a dyno still at 80km/h from memory and no wind resistance of course, most likely they would put some load in compensation on the dyno. Thats why you never usually get eh figures they quote

[jake32]

400 k`s a tank in 2.5ltr stagea ...i`m starting to feel better ..i thought it was just my guzzler

not sure about the "super touring wagon" blurb now... will have to stop 3 times for fuel just to visit mum and dad in sydney...so its super touring to the next garage..fill up blah blah blah

i guess if i`m short of cash ..i better fly virgin

[Sydneykid]

Hi guys, before Jaycar IBC, DFA and a quick tune, 14.5 litres per hundred kilometres, after = 12.0 litres per hundred kilometres. Hoping the exhaust will help some more.

[ICE12]

I get about 380 to the tank. But feeling a little better now as it is close to what others get.

Cheers ICE

[tigerleo62]

If I get less than 300k on 3/4 tank of fuel then I feel cheated...

Using BP Ultimate which is around $1.06/L I think (I don't pay much attention to the price of petrol - it is still cheaper per litre than warm coke!). Problem with BP is that there aren't any in my suburb - the closest being about 6k away...

[Enterthestagea]

15L/100km is the best I can get around town (normally 17L/100km) all depends how much weekend driving I do, dump pipe and bigger zorst certainly helped. Definetly could get 500kms or more / tank on the highway sitting on a 100 - 110km/h w a/c.

[Ben D]

Good thread.

I've been at this question for a while, as the one thing I like more than performance is cheaper performance. My stagea is stock except for a bleed set at 8 psi and a K&N panel filter. I have established that besides the weight of the car the auto is the main thing holding fuel economy back. To get decent mileage you need to lock up the torque converter in 4th gear (ie: use the overdrive). It will not do this until fully warmed up and seldom does it around town, contributing to the abysmally poor fuel economy you get under these conditions (hot weather, a/c on -18-20 l/100 km is not uncommon). On the highway you can drive for miles without the converter locked up unless you do the following: establish the cruise speed - say 100 - 110 km/h, then throttle back until you get 12-14 inches of vacuum , then gently press on the accelerator until your boost gauge reads 5-8 inches of vaccum, and then you should feel the converter lock up, after which if you modulate the throttle smoothly, you can drive it like a manual unless you go into boost, whereby the converter drops back off the lock up and your fuel economy suffers again. I have obtained 500 km out of 60 L, which is 12L/100 km on the stock set up driving it in this manner, and well justified the purchase of the boost gauge to my wife in doing so.

However I noted that in very hot weather (towing a small tinny near gladstone), the auto goes away badly, indicating to me that a trans cooler is a must. Upon fitting one (I used one out of an EVO 4 ($30 NZD !) and tucked it where the stock intercooler lives, but on the drivers side, keeping the stock trans cooler in its original position for a double whammy effect), fuel economy improved all over, and now the weather is cooling again, economy is better still (slightly leaner air/fuel ratio and cool trans fluid).

I really want to do a 3" turbo back exhaust and intercooler now because anything that improves system efficiency must improve economy off boost. Has anyone got "before and after figures" for fuel economy after these mods ? Obviously a fuel computer would be the next best thing too... I need the data to sell these things to my wife...

Thanks fellahs

Ben

[burkey22]

I just had my SAFC2 tuned and the mechanic said he dragged 15% of the fuel out of the mix. Up high in the revs he dragged 20% out. Needless to say fuel economy has improved dramatically. Don't have any figures for you yet though.

[Jay95R33]

Same,

Before Unichip install I was getting around 350-370km to 60lt at stock boost

After Unichip I'm now getting 420-450km per 60lt, and that's with the boost controler set at 11psi

They run damn rich in stock form, and just get richer with exhaust/pod/boost/FMIC..

One thing that I stumbled across a while ago was a wire on the ECU pinouts for the lockup of the torque converter !! Now I'm not sure it it's just a sensor to tell the ECU when the converter is locked up, or if it's the signal FROM the ECU telling the converter to lock up !

Would be interesting if we could get the converter to lock up faster and stay locked up for longer.

J