club.liberty.asn.au

PoidaGT wrote:

spec.B wrote:A "tank" is a pretty poor measure of economy for obvious reasons; maybe we should stick to posting our measurements in litres/100kms as measured by the trip computer only so we can compare accurately.

+1. Some people class a tank as 1/4 left, others when the fuel light comes on and others class a tank of fuel of when the car splutters and requires a jerry can to fill her back up.

It's only inaccurate when taken in isolation. If you track it over time (I use Fuelly), it becomes more accurate (particularly if you track how many L of fuel you put back into the tank each time, as you do with Fuelly).

I often wonder how accurate the trip computer really is, and if it is inaccurate, if that's consistently so across all similar cars.

Of course then you also have the issue (not an issue for us in the 2.5T forum at least) that the earlier 4Gens measured not L/100km, but rather km/L (more similar to the US mpg measurement in that higher figures are better, not lower).

Did 1000kms driving to Warrnambool and back via the Great Ocean Road last week.
Lowest average I saw was 8.2L on the way there via Princess Fwy, including a few stops in Geelong.

Average at the end of the trip was 10L/100kms which I thought was pretty good considering I never used 5th year around the G.O.R. to increase acceleration around corners (ie. I hammered it whenever possible ) and we did a lot of short trips around town on a cold engine.

I never ran the tank under 1/3, but at one point halfway through the trip i'd done 450kms and it said 250kms to empty = ~700kms(?)
2 ppl and full boot with about 50kg luggage

Where I live is not heavy traffic, but there's a lot of speed humps and roundabouts so it's constant start/stop. A few tests suggest my average for this sort of driving is between 13-13.5L/100 (much better than my V8 Holden which was close to 20L!)

Pretty happy with fuel consumption considering the vehicle's performance.

So.... can anyone clarify which mode the auto boxes get the best consumption with around the city.

Just for normal driving.

I share the car with my wife, and want to know if its best to leave it in I, S or S# ?

So.... can anyone clarify which mode the auto boxes get the best consumption with around the city.

Just for normal driving.

I share the car with my wife, and want to know if its best to leave it in I, S or S# ?

dave2221 wrote:So.... can anyone clarify which mode the auto boxes get the best consumption with around the city.

Just for normal driving.

I share the car with my wife, and want to know if its best to leave it in I, S or S# ?

Definitely not S#. Gearbox holds gears much higher up the rev range.
If your Lib is stock, the maximum throttle opening you will get In I mode is 35%.
You should get slightly better economy in I mode around the city however driving style is the biggest factor.
I tried leaving mine in I mode for several weeks and didn't notice any improvements to economy.

Cheers

I might just leave it in S for a while.

I have to agree with Peter.. i cant see any difference in economy between I and S modes. Maybe intelligent mode would make a slight difference in a dead flat town with flowing traffic, but in anything else it doesnt help.

I can say without doubt that my tune improved my economy substantially!! Before the tune the best my car would do on the freeway is about 9.5L/100kms, now it will do 7.8L/100kms.

But almost all of my driving is in stop start traffic in sydney so it averages 14-15L/100kms with no spirited driving. Spirited driving doesnt seem to make it much worse, if any worse strangely. Mind you my idea of spirited driving might be different to others

Ditto for the no difference between [I] and [S] mode. In fact the extra throttle needed in [I] mode, you need around town because it feels sluggish, probably hurts economy.
[I] mode pretty much feels like a 2.5L engine without the turbo... I can't see the point.

I tried almost exclusive [I] mode for over 5000 km when i first got my car - averaged 9.8 l/100km.
Now been driving almost exclusively [S] mode for over 9000 km - averaging... 9.8 l/100 km.

I've also had the car tuned/retuned by Matt in this time. No real difference. I think my general driving style maximises my fuel economy.

I think I-mode makes more of a difference (if any) with an auto than a manual.

It keeps me honest when I try to save fuel because it does not allow the engine speed to get too high unless I smash it. Having said that - low RPM doesn't necessarily mean better fuel economy. I get the impression there is more 'load' on the engine in some instances driving at lower RPMs.

I typically run it in I-mode because its I only really do city driving and any fuel saving is welcome. Also, my Gen4 H6 in I-mode is still more lively than my Gen3 H6 so I'm still enjoying that initial phase of ownership.

I mode on a tuned GTB I find to be plenty of power for around town etc

dave2221 wrote:So.... can anyone clarify which mode the auto boxes get the best consumption with around the city.

Just for normal driving.

I share the car with my wife, and want to know if its best to leave it in I, S or S# ?

I know you asked about auto, but with my stock 6MT, "S" mode is the most economical.
"I" is really sluggish and takes too many revs to move and uses more fuel. Not sure if it's the STI tune, but mine feels like "I" has zero boost. I would only use it when on a freeway for an extended period, and only when the revs are consistently above 2600RPM - eg. "S" uses less fuel ~3000RPM in 4th than "I" does ~2200RPM in 5th
"S#" doesn't seem to use a noticeable increase in fuel over "S" except when on a freeway doing 100kph where it uses ~8L/100 in S# vs 6-7L/100 in "S"

My average for the past 8000kms is 11.2L/100 which is mostly short distance suburbs/city driving and probably 1-2 1hr trips per fortnight. I would guess 70% S, 20% S#, 10% I

So to address your question, to get the best consumption it would depend on where and for how long you are holding a particular rev range, but probably stay with "S"

I find "I" mode is worse for economy except on the freeway.

As I stated before, I use Fuelly to track my fuel usage:

07 Lib GT-B wagon, stock, Kido tune.
Probably average about 400-450kms per tank, around town and short highway trips.
I can get 500-550 if I do a long highway trip.
I drive in S# mode a lot.

on my present run in tune in am using 16l/100 km.
Like a boss.

I keep a spreadsheet that I record date, odometer reading, fuel added and what fuel brand it was every time i fill up. Since I only ever fill the tank to the top i can then get a reading of average km/l or l/100km to compare from tank to tank. Average over 21000km in the last 20 months has been 11.88l/100km. Car now has 58000km on the clock. That 21 000 km has included BNE to CBR, CBR to Sunshine coast and back *1, CBR to Gold Coast and back *2 and CBR to SYD and back * 4, rest around town and includes occasionally towing a box trailer with stock for my wife's shop and firewood from time to time.

I use BP Ultimate whenever I can as I consistently get 0.5l/100km better economy out of it than either shell 98 or caltex 98. Around town I mostly drive in S unless towing which is S#, highway S#. I have found on the highway in S it will change down gears where as in S# it tends to hold a higher gear longer when faced with a hill for example. I have compared the difference on a CBR to SYD return run, S# resulted in a couple of litres saving over S with practically identical travel times on the same fuel over the exact same route about 1 week apart.

Next month will see a Kido tune and I will be interested in the difference this will make to both performance and fuel consumption.