Fuel Economy
11-10-2003, 09:26 PM
#1
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Fuel Economy
Because I am basically ****, and like others on this forum, obsessed with data, I thought I would share my fuel economy experience thus far.
Bear in mind most of my driving is freeway Canberra-Sydney and return.
I've not found any discernible differences between fuels (98/95, Ultimate/Optimax/Vortex) in this type of driving, and the pattern variations reflect the fact I drive from Canberra to Sydney early in the morning and am thus willing to accept more speeding ticket risk
My long term average fuel economy has stayed doggedly at 12.3L/100Km
Bear in mind most of my driving is freeway Canberra-Sydney and return.
I've not found any discernible differences between fuels (98/95, Ultimate/Optimax/Vortex) in this type of driving, and the pattern variations reflect the fact I drive from Canberra to Sydney early in the morning and am thus willing to accept more speeding ticket risk
My long term average fuel economy has stayed doggedly at 12.3L/100Km
11-10-2003, 09:55 PM
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My fuel economy hovers between 10.5 and 11.5L/100km. A mix of outer urban driving on the way to and from work during the week, and some freeway and back roads on the weekend. But then I'm a rather sedate driver as befits my gentlemanly demeanor (attempts to get tongue out of cheek - stuck- goes round talking funny all day)
11-11-2003, 03:40 AM
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timbo,
wow.. I'm impressed - I wish I'd kept a basic record of my usage so far.. I'll be doing it now ( time to get the spare Palm V into the car with a spreadsheet to track the miles, fills, cost, etc! ).
Always good to see someone who can drive exel.
Would love a copy of the data or spreadsheet to play with the stats to compare with my next few loads if possible?
What was the one really big spike / dip?
Are you planning to keep track of it for a while longer? Is this a log you have to keep for a lease, or work claims?
Hope you'll keep posting monthly updates!
Q: has anyone else kept this sort of detail?
++dez;
wow.. I'm impressed - I wish I'd kept a basic record of my usage so far.. I'll be doing it now ( time to get the spare Palm V into the car with a spreadsheet to track the miles, fills, cost, etc! ).
Always good to see someone who can drive exel.
Would love a copy of the data or spreadsheet to play with the stats to compare with my next few loads if possible?
What was the one really big spike / dip?
Are you planning to keep track of it for a while longer? Is this a log you have to keep for a lease, or work claims?
Hope you'll keep posting monthly updates!
Q: has anyone else kept this sort of detail?
++dez;
11-11-2003, 04:37 AM
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Timbo,
Here's my consumption, don't have as many fills as yourself but my average is around 16L/100km mostly in city driving (with heaps of stop/start). Fills 1-4 are Optimax, the remainder Ultimate but can't notice any difference at this stage.
Here's my consumption, don't have as many fills as yourself but my average is around 16L/100km mostly in city driving (with heaps of stop/start). Fills 1-4 are Optimax, the remainder Ultimate but can't notice any difference at this stage.
Last edited by Pappy; 11-11-2003 at 04:41 AM.
11-11-2003, 03:51 PM
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Dez:
Would love a copy of the data or spreadsheet to play with the stats to compare with my next few loads if possible?
Would love a copy of the data or spreadsheet to play with the stats to compare with my next few loads if possible?
Dez:
What was the one really big spike / dip?
What was the one really big spike / dip?
Dez:
Are you planning to keep track of it for a while longer? Is this a log you have to keep for a lease, or work claims?
Hope you'll keep posting monthly updates!
Are you planning to keep track of it for a while longer? Is this a log you have to keep for a lease, or work claims?
Hope you'll keep posting monthly updates!
Am happy to post monthly updates, but I suspect they will be boringly similar :o
Pappy:
Here's my consumption, don't have as many fills as yourself but my average is around 16L/100km mostly in city driving (with heaps of stop/start). Fills 1-4 are Optimax, the remainder Ultimate but can't notice any difference at this stage.
Here's my consumption, don't have as many fills as yourself but my average is around 16L/100km mostly in city driving (with heaps of stop/start). Fills 1-4 are Optimax, the remainder Ultimate but can't notice any difference at this stage.
My coit dynometer is not too sensitive so I can't notice anything there, even in relation to 98 vs 95
Last edited by timbo; 11-11-2003 at 03:56 PM.
11-11-2003, 06:54 PM
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Cracked it for under 10L/100km on my fill this morning! 41.6 L consumed for 418km travelled, or ~23.6miles per US gallon. I use Caltex PULP with NBE (no bloody ethanol).
11-11-2003, 07:16 PM
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Amazing figures, labrat -- I did try one run with a/c off and "reasonably" light throttle openings, but still at hwy speeds, and achieved a best of 11.5L/100km.
I must admit I have not tested with DSC off, which is reputed to give better economy (but offers more temptations in the handling dept )
Heck, what AM I talking about? I bought this car to have fun, and because I reckon I can get all you (taxpayers) to pay for most of my fuel :D
I must admit I have not tested with DSC off, which is reputed to give better economy (but offers more temptations in the handling dept
)Heck, what AM I talking about? I bought this car to have fun, and because I reckon I can get all you (taxpayers) to pay for most of my fuel :D
Last edited by timbo; 11-11-2003 at 07:33 PM.
11-11-2003, 07:22 PM
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I simply don't car about the fuel economy when I am driving around Adelaide and surrounds. I punch the car off the lights, I keep the gears low and revs high when driving through bends or in the hills. I am not happy unless I hear the redline beep within 10 minutes of beginning any drive.
Fuel economy was *terrible* when the car first arrived, and now I am about to clock 10k on the odo, fuel economy is *normal*. It is what I am used to. I guess it is somewhere around 12/100 when driving around the city. On the open highway it can get as low as 10/100 (far easier to test as well ...)
Fuel economy was *terrible* when the car first arrived, and now I am about to clock 10k on the odo, fuel economy is *normal*. It is what I am used to. I guess it is somewhere around 12/100 when driving around the city. On the open highway it can get as low as 10/100 (far easier to test as well ...)
11-11-2003, 08:06 PM
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Wow... redline in tem min... Is the Renesis up to temperature by then?
I haven't ordered my 8 yet (waiting for the finances to work out) but have been a bit worried about running the car cold. It only takes me 7 min to drive from home to work... much to short a drive to have any "fun"
I haven't ordered my 8 yet (waiting for the finances to work out) but have been a bit worried about running the car cold. It only takes me 7 min to drive from home to work... much to short a drive to have any "fun"
11-11-2003, 08:15 PM
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I live on a semi-main road near the city. Basically at the end of this road is the Adelaide parklands. It is exactly 2km from my house to the end of the road. In the morning, if I get stuck at the lights half way down this road (about 800m from home), and then stuck at the lights at the end of the road (another 1200m), then the car is probably getting near operating temperature. This would be about 3 or 4 minutes from starting the car.
But we are forced to buy this expensive oil that has good operating characteristics when cold. We are driving a free revving engine with few moving parts. Redline from cold is fine IMHO. If you weren't supposed to do it, the ECU would stop you.
My previous car (2000 Celica) gave you fuel starvation at 6k rpm when cold, but at about 7900 rpm when warm. The Celica's ECU thought revving when cold was bad. The RX8's ECU could care less.
But we are forced to buy this expensive oil that has good operating characteristics when cold. We are driving a free revving engine with few moving parts. Redline from cold is fine IMHO. If you weren't supposed to do it, the ECU would stop you.
My previous car (2000 Celica) gave you fuel starvation at 6k rpm when cold, but at about 7900 rpm when warm. The Celica's ECU thought revving when cold was bad. The RX8's ECU could care less.
11-28-2003, 09:40 AM
#14
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on fuel econ, talking with some bod's at the service centre I'm rather partial to loitering about, they tell me that there shouldn't be any noticable difference between fuels per se.
but every mazda 'dude' in the employ of any form of mazda related company concurs to date that Shell Optimax is going to give you back as much of the CAT caused KW loss!
And I hate supporting that Iraq blasting bombastic bloody firm, but hey, I'm not a complete nut case. Can't change the world, perhaps alter my view of it, but change, that's for metiorites and asteroids!
++Dez;
but every mazda 'dude' in the employ of any form of mazda related company concurs to date that Shell Optimax is going to give you back as much of the CAT caused KW loss!
And I hate supporting that Iraq blasting bombastic bloody firm, but hey, I'm not a complete nut case. Can't change the world, perhaps alter my view of it, but change, that's for metiorites and asteroids!
++Dez;
11-28-2003, 03:33 PM
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Originally posted by Dez
on fuel econ, talking with some bod's at the service centre I'm rather partial to loitering about, they tell me that there shouldn't be any noticable difference between fuels per se.
but every mazda 'dude' in the employ of any form of mazda related company concurs to date that Shell Optimax is going to give you back as much of the CAT caused KW loss!
And I hate supporting that Iraq blasting bombastic bloody firm, but hey, I'm not a complete nut case. Can't change the world, perhaps alter my view of it, but change, that's for metiorites and asteroids!
++Dez;
on fuel econ, talking with some bod's at the service centre I'm rather partial to loitering about, they tell me that there shouldn't be any noticable difference between fuels per se.
but every mazda 'dude' in the employ of any form of mazda related company concurs to date that Shell Optimax is going to give you back as much of the CAT caused KW loss!
And I hate supporting that Iraq blasting bombastic bloody firm, but hey, I'm not a complete nut case. Can't change the world, perhaps alter my view of it, but change, that's for metiorites and asteroids!
++Dez;
) My average is 16.3L/100km - I can't get anywhere near 12L/100km let alone 10L/100km mentioned by other owners no matter how easy I drive the RX8.I wonder if the earlier RX8's are worse than the latter ones? There appears some mention of this by the US guys but very hard to quantify at this stage.
As far as power goes - the car is running great and I can't discern any major difference between Shell and BP. I'll switch back to Shell next tank and run it for a few tanks to compare.
As you mention - Mazda is definitely pushing Shell's Optimax.
Pappy.
11-28-2003, 04:58 PM
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Best I've seen is 10.5/100 all hwy with A/C on and DSC/TSC off. Around town (half city, half hwy) I am getting about 13.5/100. I've got a heavy foot too.
I don't thing the type of fuel will have any real effect on economy. I've run a couple of tanks of regular unleaded (91) through my car and got the same economy as 95 and 98 PULP.
I don't thing the type of fuel will have any real effect on economy. I've run a couple of tanks of regular unleaded (91) through my car and got the same economy as 95 and 98 PULP.
11-28-2003, 05:30 PM
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Originally posted by D.G.W.
Best I've seen is 10.5/100 all hwy with A/C on and DSC/TSC off. Around town (half city, half hwy) I am getting about 13.5/100. I've got a heavy foot too.
I don't thing the type of fuel will have any real effect on economy. I've run a couple of tanks of regular unleaded (91) through my car and got the same economy as 95 and 98 PULP.
Best I've seen is 10.5/100 all hwy with A/C on and DSC/TSC off. Around town (half city, half hwy) I am getting about 13.5/100. I've got a heavy foot too.
I don't thing the type of fuel will have any real effect on economy. I've run a couple of tanks of regular unleaded (91) through my car and got the same economy as 95 and 98 PULP.
Pappy.
11-28-2003, 08:54 PM
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Originally posted by Pappy
D.G.W. - your consumption figures don't appear attainable by my RX8. Out of curiosity can I ask the last 3 digits of your VIN? Mine is 380.
Pappy.
D.G.W. - your consumption figures don't appear attainable by my RX8. Out of curiosity can I ask the last 3 digits of your VIN? Mine is 380.
Pappy.
Timbo
11-28-2003, 10:15 PM
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I've read reports about variability of quality in Optimax. I have a fuel card for BP so mine gets Ultimate exclusively.
Pepe, what rev's do you cruise at e.g when you're on 60-70, 100-120? I keep mine under 3,500 and I get 12.5-13.5L/100km when behaving (no redlining), no WOT.
I find the US experience on fuel economy very amusing... I wonder how smart some of them are. I've seen a bunch of them saying "I cruise at 5000 RPM" and my fuel economy sucks.... no bloody wonder. Constantly running with the second fuel injector going ain't gonna do much for economy. Then I read threads about guys coasting in neutral at 90MPH.. and this reinforces this.. but I digress.
I love the fact that the engine is virtually silent under 3000RPM with minimal pressure on the throttle... but I also love the roar you get when you ask for more.
It's been a while since I've tracked fuel economy... might do it again and see what it's like now I have a few thousand on the clock.
Pepe, what rev's do you cruise at e.g when you're on 60-70, 100-120? I keep mine under 3,500 and I get 12.5-13.5L/100km when behaving (no redlining), no WOT.
I find the US experience on fuel economy very amusing... I wonder how smart some of them are. I've seen a bunch of them saying "I cruise at 5000 RPM" and my fuel economy sucks.... no bloody wonder. Constantly running with the second fuel injector going ain't gonna do much for economy. Then I read threads about guys coasting in neutral at 90MPH.. and this reinforces this.. but I digress.
I love the fact that the engine is virtually silent under 3000RPM with minimal pressure on the throttle... but I also love the roar you get when you ask for more.
It's been a while since I've tracked fuel economy... might do it again and see what it's like now I have a few thousand on the clock.
11-28-2003, 10:19 PM
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Timbo - your car's consumption has been fairly linear and quite low compared to mine - since my driving is mostly city based I would expect a higher consumption but would like the occasional dip down to 12 or even 10L/100km .
Anyway, my 8 has only has 2,300km on the clock so I'll keep monitoring and hopefully achieve lower consumption as I cover more kms.
BTW - thanks for your VIN details. Just wanted to see if there was some correlation between fuel consumption and vin/build dates. For the moment I guess there isn't.
Pappy.
.Anyway, my 8 has only has 2,300km on the clock so I'll keep monitoring and hopefully achieve lower consumption as I cover more kms.
BTW - thanks for your VIN details. Just wanted to see if there was some correlation between fuel consumption and vin/build dates. For the moment I guess there isn't.
Pappy.
11-28-2003, 10:28 PM
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Sco - I usually cruise around 3,000rpm with visits to 6,000+ during acceleration. I have babied the car and kept the revs below 4,000 for a few fills but the best I could get was 14.6L/100km - it ain't much fun driving like this!
Worst consumption was 17.7L/100km when revving hard and having fun .
Pappy
Worst consumption was 17.7L/100km when revving hard and having fun
.Pappy
11-28-2003, 10:52 PM
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Originally posted by sco
Yuck.
Sorry I called you Pepe, Pappy... hell it's saturday afternoon and brain is not in gear
Yuck.
Sorry I called you Pepe, Pappy... hell it's saturday afternoon and brain is not in gear
Pappy
11-29-2003, 05:23 AM
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Pappy, my VIN is 319.
I don't use "craptimax" any more after the bad press it got here on the forum a few months back. I'm using Mobil synergy 8000, simply because it is the only servo between my house and work that sells 98RON PULP. But like I said earlier, I don't think which brand you use has an effect on economy. Power and engine longevity - that's another topic.
I remember reading some US threads with guys saying that they "cruised" at 5000-7000rpm. Laughed my **** off at the time. They obviously took the "rotaries love to rev" quote literally. For me, I aim to cruise around at whatever gear gives me 2500-3500 rpm. (Keep it <3750 if you can). I've got a few rules of thumb that I unconciously use:
3rd - 45-60kph
4th - 60-70
5th - 70-85
6th - >85
...unless of course I feel like hearing the music of the Renesis purring along at >4000rpm.
I don't use "craptimax" any more after the bad press it got here on the forum a few months back. I'm using Mobil synergy 8000, simply because it is the only servo between my house and work that sells 98RON PULP. But like I said earlier, I don't think which brand you use has an effect on economy. Power and engine longevity - that's another topic.
I remember reading some US threads with guys saying that they "cruised" at 5000-7000rpm. Laughed my **** off at the time. They obviously took the "rotaries love to rev" quote literally. For me, I aim to cruise around at whatever gear gives me 2500-3500 rpm. (Keep it <3750 if you can). I've got a few rules of thumb that I unconciously use:
3rd - 45-60kph
4th - 60-70
5th - 70-85
6th - >85
...unless of course I feel like hearing the music of the Renesis purring along at >4000rpm.
11-29-2003, 05:40 AM
#25
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"craptimax".... I guess all the fuel that we have interstate is different... in Melbourne (All Metro Shell) has fuel from Geelong - remember once they shut down the first to go was the Optimax or possible "craptimax" I don't think Newcastle or Sydney is from the same refiner - I suspect all the fuel BP, Mobil and Craptimax is the same stuff.