5.4 fuel efficiency

[Sep 97 EL XR8]

Hi everyone
I have had a ba xr8 for 6 months and I have had managed to get 11.2 travelling from adelaide to Melbourne, but am somewhat dismayed about the city driving round Melbourne. While I'm first to admit I don't drive it like a grandpa, but I also don't drive like racing driver. I suspect a bit over the average xr8 driver.

I have been told by quite a few different people that I should run BP ultimate in the xr8. Which I have been for 4 months- been through quite a few tanks.

What Im after is the realistic/acceptable/common place fuel efficiency for the 5.4 around Melb/city.

Lately my 80km to empty warning comes up at about the 250 to 260km makes. So a full tank will run out approx 330 to 340. Which seems excessive. For a comparison my el xr8 did between 350 to 400 on a tank.

Surely new cars should do better feel efficiency?

If BP ultimate is as good as every one seems, I would be travelling even less!

So what's every one doing? Should I be putting different fuel. Should there be a brick under the accelerator pedal (only joking)




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[Brazen]

Do you know what your L/100km is in city driving? It's not unheard of for 6 cylinder BAs to get 15L/100km in city driving - so imagine the 5.4 could be higher again.

[You Yangs]

I would of thought below 10l/100km would of been achievable on the open road, 11.2 seems highish.
My AU 5L used to see low Nines with a car load of people and luggage in the boot.

[sbcb]

BP ultimate won't make much difference. They are tuned for 91.
What your old EL was getting is about what I've been getting from two BA Xr8s I've owned.
If your cars running correctly then it's all about driving style, but as a rule stop/start urban lifts boss v8s from bad economy to the words "fuel economy" being a completely alien language lol.

[kcodezd]

I am averaging mid 17/100 in mine. All city no highway at all. Traffic lights are the problem. I drive 16km to work, but the longest stretch between lights is about 1.6km.

[xisled]

When I was driving my BA GT daily I think I was getting around 13.9. I thought wow it's similar figures to what my BA XT was getting.

As others have said the actual brand of fuel won't make a massive difference.

[Sep 97 EL XR8]

With a 70l tank and 350km = 18.9 - so not that great.

Seems to be higher than everyone's else's.

The other query is if the car is tuned for 91, why does it ping when it's used.

Is it hard to get it tuned for 98.

So all the comments I've read about if you used higher octane fuel, you should get better fuel efficiency is incorrect


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[Mercury Bullet]

Originally Posted by Sep 97 EL XR8

With a 70l tank and 350km = 18.9 - so not that great.

Seems to be higher than everyone's else's.

The other query is if the car is tuned for 91, why does it ping when it's used.

Is it hard to get it tuned for 98.

So all the comments I've read about if you used higher octane fuel, you should get better fuel efficiency is incorrect


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Higher octanes give you a higher resistance to detonation - nothing more.
To give some indication, LPG is higher in octane than 98. E85, the same.
If you are buying it to get better fuel economy, don't.

My current fuel consumption on a 335 engine is 12.7/100 or ~500km a tank.
Unless with mates then 150km/tank.

[Whitey-AMG]

I've seen 19l/100 on my BFGT around town....
Heavy cars , stop go heavy traffic and big capacity engine is always gonna end in fuel economy tears. Mine is tuned to 98

On the highway at a steady 90klmh I see @ 7l/100.

[ford man xf]

Originally Posted by Mercury Bullet

Higher octanes give you a higher resistance to detonation - nothing more.
To give some indication, LPG is higher in octane than 98. E85, the same.
If you are buying it to get better fuel economy, don't.

My current fuel consumption on a 335 engine is 12.7/100 or ~500km a tank.
Unless with mates then 150km/tank.

Correct. The higher octane rating means you can run a higher compression ratio without it detonating, you can advance the timing more as well.

Increased fuel consumption really can come down to driving style as well, the car learns your driving style/habit and adjusts accordingly, I haven't tried myself but if you disconnect the battery for x amount of hours it resets the ECU memory.

But the most common cause can be air filter, o2 sensors, spark plugs. When did you check these last? Do you know when your spark plugs were last changed? Pull the o2 sensors out and take a look at the carbon deposits on them, how bad are they?

[383hq]

Originally Posted by Mercury Bullet

Higher octanes give you a higher resistance to detonation - nothing more.
.

Correct.
but higher resistance to detonation = more advance on the timing when tuning, which equals better bang, or as engineers would put it, better BMEP.
Didn't matter much in the days of carby, (other then levels of protection) it does now..

Naturally you get to a point where you can't get any more air in, so you need boost ^^ see what I did there

Fuel economy is a function of throttle position (foot)

[ratter]

Late model cars are factory tuned in many cases to drop power at cruise speeds and load to achieve better fuel economy

[lamborghinifan]

My 6l caprice is 19-23l 100, all low speed city, my old 5.4 ute was similar, my previous 6l caprice was similar, my turbo terry was also similar. Where I live an average round trip is no more than 5k, all 60kph.... so yes it's not far fetched if you drive in the right conditions.
But they all dropped to 10 ish on a proper highway run, except the turbo terry which never really got below 13l/100
Hope that helps. And no, my wife and I aren't really leadfoots, just general driving.

[M&Ms]

My BA XR8 long term average was 19.8 L/100 @ 30km/h average speed.
My FG GT was 18.6 @ 32km/h.
My FGX XR8 is 17.8 @ 38km/h.
All 3 cars are auto, predominantly driven in Sydney Traffic, with the odd run North up the coast, or west out to Lithgow.

My BA got better economy and performance on 95 Octane fuel. The BA V8's don't have knock sensors so you get zero benefit in using 98 over 95. Best performance was using Caltex I recall.

I never saw any better than 11-12 L/100 on the freeway in the BA, vs. my FG which would get down to 9.5. The FGX is about 10.5. The BA being a 4 speed would sit at 2200 RPM @ 110km/h, vs 1800 RPM in the 6 speeds. The supercharged 5.0 motor uses more fuel than the NA 5.4 at cruising speed.

Don't forget the 4 speed is also less efficient than the 6 speeds which also affects economy, plus the BA tune is not as refined as the BF onwards for fuel efficiency.

Similar to you, my fuel light would come on at about 260 - 270 in my BA. I probably drove in a similar manner to most enthusiasts, normal at some times, and letting it sing at other times.

Hope this helps.

Originally Posted by Sep 97 EL XR8

Hi everyone
I have had a ba xr8 for 6 months and I have had managed to get 11.2 travelling from adelaide to Melbourne, but am somewhat dismayed about the city driving round Melbourne. While I'm first to admit I don't drive it like a grandpa, but I also don't drive like racing driver. I suspect a bit over the average xr8 driver.

I have been told by quite a few different people that I should run BP ultimate in the xr8. Which I have been for 4 months- been through quite a few tanks.

What Im after is the realistic/acceptable/common place fuel efficiency for the 5.4 around Melb/city.

Lately my 80km to empty warning comes up at about the 250 to 260km makes. So a full tank will run out approx 330 to 340. Which seems excessive. For a comparison my el xr8 did between 350 to 400 on a tank.

Surely new cars should do better feel efficiency?

If BP ultimate is as good as every one seems, I would be travelling even less!

So what's every one doing? Should I be putting different fuel. Should there be a brick under the accelerator pedal (only joking)




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[smoo]

Originally Posted by Bluey-GT

I've seen 19l/100 on my BFGT around town....
Heavy cars , stop go heavy traffic and big capacity engine is always gonna end in fuel economy tears. Mine is tuned to 98

On the highway at a steady 90klmh I see @ 7l/100.

image

7l/100km, is this down hill with a tail wind?!?
None of my falcons have achieved anywhere near that and I've owned close to 20. In fact 7.0 is not much worse than my old BMW 3 series diesel which was 6-6.2 l/100km highway.
My current AU wagon will return 7.8 highway which is good and one of the most economic Falcons I've had.
My FG Xr8 ute is consistently 10.5-11 highway.
My old BA 5.4 3V Fairlane would return 9-9.5 highway.

I've always thought city figures are pointless to look at. Too many factors at play, how it's driven, the terrain, stop go etc. it's not a race to the speed limit, try and keep a decent following distance and anticipate traffic lights, should see a reduction in consumption.

[Mechan1k]

From the 6-cyl mid-6's "average" is easily achievable.
The above is an instant consumption graph though .... I can make my FG show 0.0L/100km on decel ... so it's not hard to show a low instant figure.

Probably harder on one of the older 5.4's though.

If i had a V8 though ... I wouldn't be worrying about fuel consumption though ... I'd be more interested in the sound at the time.

[Whitey-AMG]

Originally Posted by Mechan1k

From the 6-cyl mid-6's "average" is easily achievable.
The above is an instant consumption graph though .... I can make my FG show 0.0L/100km on decel ... so it's not hard to show a low instant figure.

Probably harder on one of the older 5.4's though.

If i had a V8 though ... I wouldn't be worrying about fuel consumption though ... I'd be more interested in the sound at the time.

Yes, it's instant consumption.
It was flat highway , not downhill and no tailwind. Kept speed at steady 90 in 6th gear. Was just showing how in the right conditions without a heavy right foot that "economy" is possible with these cars on long stretches if you're that way inclined.....

My overall average sits @ 16/100

Lowest average I've seen is @ 14/100 with good highway and less suburban stop start.
Highest I've seen is 23/100..... no highway. Stop start going to work over a couple of weeks in heavy traffic. Thought I had a fuel leak somewhere

Regardless, I reckon I've spent more time trying to get it to suck more petrol and make more power. Eventually it will get a YT whipple anyways.

[Sep 97 EL XR8]

Thanks for all the info, it appears the xr8 is about average around town in comparison with xr8 - good info M&M and every one else.
I will take all your advice and not worry about BP ultimate or any 98. I will just stick to 95.

But another query should one type of fuel company be used for better performance/ fuel efficiency? Or cane you out whatever's available at the time - 95 off course?


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[Hardtopxb]

I have just come back from a trip from Townsville Far nth qld to Moruya south coast nsw, and return. Did city driving, country driving, Expressway etc. 50klm to 110 klm etc. I averaged 13.4/100 klm. using 95 only. I thought this was not bad. I am not a granny driver..

[Tommie]

I have a BA XR8 4spd, tuned to 98ron. Normal highway driving would net me about 13.5 - 14 ltrs per 100. Not babying though just good driving. Once on the Hume Hwy from Canberra to Newcasle using cruise control, so barely touching accelerator, i managed to get 10 ltrs per 100. Was just testing to see if it could be done.. was a long drive though.

Around town I get 17-18ltrs, which seems to be on average with some others here. Have 4.11 gears though which probs makes it use a bit more, but worth it.

[Polyal]

Certainly was/is a slap in the face when the 5.4 came in. More power for sure but not exactly any more efficient.

Not sure of the weight differences but the BA was porkier too...maybe some diff gears might help off the line to you dont need to dig so deep into the throttle?

[ebv8]

I have a BA GT 5sp with 4.11 diff, i get 11 on the freeway and 13-17 on avg around town depending on where i go that month
best i have got was 8 but that was 90km/h on a flat road for an hour but 11 is easy to maintain on most highway/freeway runs
my adventra gets 10 on the freeway and up to 25 around town

[Junkyard-Dog]

I bet those 4.11 diff gears make a big difference ebv8. Even though the higher rpms are probably hampering your highway fuel economy, I wouldn't be surprised if they actually helped around town..?

[Kieron]

Manual FG XR8, filled it up last night (United E10) and drove it to work this morning, just took this pic -

[IMG][/IMG]

I haven't reset the trip computer since I bought the car new in 2009. Driving consists mostly peak traffic up/down Perth's Mitchell Fwy 3 days/week.

Best/most reliable car i've ever owned, love the thing and can't image giving her up.

[boss351290]

A 5.4 efficient?? Your kidding me.

[Kingsley]

People buy V8's AND want fuel efficiency??? That's the last thing I expect when I buy a V8!!!

[Brazen]

In a the old days you used to buy a V8 for efficiency. My dad and grandfather used to order their Fairlanes with V8s, as the 'engines worked less'.

[Whitey-AMG]

Originally Posted by boss351290

A 5.4 efficient?? Your kidding me.

Well as far as V8's go it ain't that bad.
Considering the E series 5.0 ran similar consumption average ( @15l/100 ) and the E series was some 200kg lighter and ran 100 rwkw less.

Then there's the old Skool 4.9 and 5.8 motors , particularly in the CD and XE. Having owned one I reckon it ran 30l/100 on a bad day....

[kypez]

Originally Posted by smoo

7l/100km, is this down hill with a tail wind?!?
None of my falcons have achieved anywhere near that and I've owned close to 20. In fact 7.0 is not much worse than my old BMW 3 series diesel which was 6-6.2 l/100km highway.

My EcoBoost Falcon did! 6.41 on the highway. 60 litres got me 950 kms.

The tanks on these are only 68 litres and I never filled the XR8 more than 64 litres ever! Average was around 60 litres.

On topic, my BA XR8 was pretty good whilst it was a road car. Used to sit around 15-16/100 around town and got to high 10's on the highway. I was happy with that given the extra power.

I put some cams into mine and got it tuned as well which did improve it as I found myself not having to give it as much to get out of the mid range dead spot. Improved fractionally, low 10's/high 9's on the highway and closer to 14-15's around town.

how many kms on the BA. I think 330-340 a tank is a bit low. I used to get around 400 around town and 670 was the best on the highway (hume, nice steady 110).

Though, $2000 buys a lot of fuel for very little fuel savings!

[Mr Brooksy]

We had the 5.4 220 and that was not at all light on fuel. Best I ever saw was 11L/100km on the trip from Newcastle to Adelaide and similarly from Newcastle to Brisbane more often it was 12s, whereas the Typhoon gets 8L/100km on pretty much every freeway every time. Around town the consumption was much more line ball V8 was about 15-16, and the F6 14-17. But I'm guessing that has more to do with my love of the rush you get from the turbo Vs my wife plodding along on her rumbling V8.

What gearbox have you got in the XR8? That'll surely make a bit of difference too. Assuming you have the 4 speed, the tall first gear will hurt more in town than you realise.