Hi, everyone.
Because I still didn\'t strike oil in the back garden, I went through fuel consumption today. The published specification (for the 232 model) says:
Fuel consumption
(EC regulation mode)
combined 11.2L/100km 25.2mpg
extra urban 8.7L/100km 32.5mpg
urban 15.6L/100km 18.1mpg
Today I did a carefully monitored test and I got 14L/100 km (20 mpg) on the motorway, and the engine was doing only around 5000 to 5500 rpm. The difference from 8.7 l to 14 L /100 is a bit too big to be explained by driving style etc. I was wondering if it\'s just my car or is it all the engines that are reporting this sort of fuel consumption. Even if price is no object (and I am not that rich as yet) I don\'t fancy filling up every 200 odd miles. I am going to take it back to the dealers (you betcha), I was wondering how many of us are having this issue and how many live in the bliss of official figures.
All the best
Teo
many people seem to be saying same so doesn\'t look that odd & 2b honest i think the "official" figures are usually a fat portion of BS for all manufacturers (http://instagiber.net/smiliesdotcom/contrib/geno/rofl.gif) just reminds me of me ole impreza figures for a UK turbo were supposed to be 29.9 MPG pah i once managed nearly 28 but that was cause the clutch was buggered & i ha dto drive sub2500RPM (http://smilies.networkessence.net/s/contrib/aahmed/sad.gif)
Si
Quoteand the engine was doing only around 5000 to 5500 rpm
have you considered changing up (http://www.gamers-forums.com/smilies/otn/happy/11zwinky.gif) lol only kidding i no the rotary likes to rev (http://www.gamers-forums.com/smilies/contrib/geno/jump.gif) lol
Si
teo
I am getting 21mpg in motorway only at sub 5000rpm.
so the \'official\' figures are way out.
I agree its not fun to fill up so often.
Yvonne
5000-5500 RPM?
Thats , in 6th, 100 - 110MPH.
Official MPG figures will be at 60mph or whatever (actualy a cycle between 40ish and 80ish averaging 60).
60mhp = 3000RPM.
110mhp wont be the most economical way to drive any car.
Hi all,
Going from my experience in the past with rotaries.
At around 4000-5000rpm is when the extra ports (secondary ports) will start to open up. So you will go through more fuel for sure.
If you kept the revs under 4000rpm you should get reasonable economy.
With the older Mazda\'s the 4000rpm mark was when the secondaries opened up (again using more fuel).
I will be able to tell you more soon when I get mine, hopefully next week.
Rob
I appreciate your point about not expecting good fuel consumption if you are driving very fast.
I was driving between 60 and 85 mostly in 6th. Which, to be honest, is slower than i would normally drive. This was due to the bad weather and the fact that I am "running in" the new car.
so although the figures may be officially accurate its still somewhat disappointing to get this kind of consumption in everyday, fairly tame driving.
In my last car, I seem to have got similar performance to the official figures. maybe only 10% less (and I used to thrash that car). whereas this is 33% lower with no thrashing.
all the best
Y
for M25 traffic reasons I was between 65 and 85 mph most of the time.
I am going to take the car back to the dealers on Thursday 4th Dec and will see what difference that makes.
Teo
so the fuel consumption isnt that good at all... how is taking your car back to the dealer help? do they just give you a few extra gallons of fuel to take away with the car? i just dont get it. Is there any thing you can do to the car to less the fuel consumption? like restrict something? because 90% of the time u are driving sensibly so u just dont need all the power. hmmm ??
I realised that I have had the AC on the whole time I have had the car. Am I right in thinking the fuel consumption would be affected by the AC?
anyway I am going to keep it turned off and see what happens.
I can\'t see what\'s wrong in getting the garage to check over the car if the fuel consumption is high?
take care
Yvonne
QuoteOriginally posted by Yvonne
I realised that I have had the AC on the whole time I have had the car. Am I right in thinking the fuel consumption would be affected by the AC?
anyway I am going to keep it turned off and see what happens.
I can\'t see what\'s wrong in getting the garage to check over the car if the fuel consumption is high?
take care
Yvonne
It will make a difference - Air Con requires power to operate which comes from the engine burning fuel.
I\'ve tried not using the aircon in my FD but it tends to steam up if I do that!
Iain
yeah air con makes a huge difference, it eats up power too and more fuel. i was driving my friends ford laser, 1990 model (ie crap box) it had absolutely no power, and i was screaming, "shit we are not gonna make up this hill!!" and my mate hits the air con switch (off) and rrrrmmmm it felt like something kicked in and in that crappy car, it felt like the power doubled, i was laughing and i said to him, "so... is that the NOS switch?? oh yeah!!!" lol
oh and his fuel gauge doesnt work either so what he does is reset the mile counter every time he fills up, it can do about 400kms a tank, yeah last summer he rang me and said he ran out of fuel cause he just relised the car doesnt do anywhere near 400km a tank when the air con is on :)) so i had to fetch some gas haha
yeah so from experience, air con makes a diff in econ. :)
I think that many of you find that after say 5000 miles the fuel consumption should improve a little as the engine will be nicely run in.
I am suprised that people are driving the cars hard staight off as the engines are not run in from the factory.
When I drove the preproduction model with the 6 speed box I noticed that the revs were at 3500 at 70 mph.Is that the case on the production model?
On the 3rd gen RX7 70mph is 3000 revs.
Careful running in has got to help with both power and economy later on.
Kind regards
Carl
my dealer advised me to keep it under 5000 rpm for first 1000 miles although occasion bursts would be ok and I think the manual suggests 7000.
so I am only doing what advised.
yvonne
Hi Yvonne,
thanks for the info,I have heard various things from different dealers.
What are your revs at 70mph?
Kind regards
Carl
:wave
The manual states no running in is needed BUT engine life and economy may be improved...yada yada:
For first 600miles, keep revs below 7k, dont race engine, dont WOT to much.
I followed those instructions (mostly).
As to RPm/Speed, in 6th , each 1000rpm = 20mph, so 3000=60mpg, 4000=80mph.
You cant compare the renesis to the RX-7 engines as port openings and injectors come online at different RPMs.
Hi Rob,
I appreciate that the port openings are diffrent as I have an RX8 engine to look at.
If the handbook says that then that is what you should do.
The reason I mentioned about the RX7 engine is that actually the primary(or first opening)ports are almost identical to the RX8 engine.They are slightly larger.
Port use and opening are determined by throttle position as well as revs,and since the RX8 has a fly by wire electrical operation the ecu should determine the optimum position for it at all times.
It seems that the economy is in the same region as the RX7 in stock form.Maybe it is just due to the fact that everyone is having fun at the moment?When they are used to the car then not only will it be run in but driving it hard will be less often?
Of course I may be wrong but time will tell.
Thanks for RPM/MPH comparison,70mph must be still 3500 rpm then.
Kind regards
Carl
As to RPm/Speed, in 6th , each 1000rpm = 20mph, so 3000=60mpg, 4000=80mph.
just checked this out in the RX8 and its totally accurate
Yvonne
I think its the same in 3rd but 10mph too.
I.e. in 3rd :
1000rpm = 10mph
4000rpm = 40mph.
If you drive ANY car at 5500 / 6000 RPM for extended periods of time you will burn up the fuel like crazy... :rollin I don\'t know what people expect :confused:
Hi Tony,
Long time no hear.Hope you are well.
Thanks for the News letter you keep sending me.
Hows the RX3 coming along?Got that engine built yet?
Kind regards
Carl
QuoteOriginally posted by Carl
Hi Tony,
Long time no hear.Hope you are well.
Thanks for the News letter you keep sending me.
Hows the RX3 coming along?Got that engine built yet?
Kind regards
Carl
Cheers Carl, all good here. The 10A PP is being built at the moment (after some more "drama\'s"), RX3 has been painted and will finally be running January :cool I will post up some pic\'s when it is running on the track.
No worries about the news letter, will keep dropping them to you from time to time.
:wave
All the best
I just filled up again and got 17.7 mpg.
that is with entirely short, local journeys from cold, no a/c.
so could be worse!
I may not make the pub on Tues now as I seem to have the flu, (high temperature and the lot) so unless a miraculous recovery comes along, I\'ll have to wait until next month.
all the best
Yvonne
Was chatting to by bro-in-law this weekend and I\'m seeing better MPG than his late 90\'s v6 saab 900.
Also had a look at the new MG ZT260 (V8 powered).
0-62 in 6.2 etc etc, bigger and hevier than the RX-8 no doubt, but MPG? Shoking. 27mpg highway, 15mpg urban, eeek..
QuoteOriginally posted by Carl
Hi Tony,
Long time no hear.Hope you are well.
Thanks for the News letter you keep sending me.
Hows the RX3 coming along?Got that engine built yet?
Kind regards
Carl
Is this the Tony from RX7 Heaven out of interest?
Hi Rich,
No it\'s Tony Stenhouse from Mazda Rotary Enthusiast\'s club in NZ.
Kind regards
Carl
Aha, do they have a website at all? Sounds interesting.
I\'m a member of the FD-Kai NZ group, you see these names get banded about, just wondered if it was one and the same. Obviuosly not...
20B_boy - //www.mrec.homestead.com is the web site.
Don\'t you get better economy by turning off the traction control (hold the button down for 10 seconds to switch it all off) before heading off on a long journey?????? and then none of this.... :burnout
which button is this exactly?
i don\'t think I dare do this even if it does improve fuel economy after all I manage to skid the car quite easily already.
Yvonne
Yesterday I took the car back from the dealers, they declared that they rigged the car up to some computerised contraption, ran the tests and declared that all is OK. I did not get any printout or anything, not sure what to think. My evil demon on the left shoulder is saying that they just kept it in the courtyard, said "what is he on about, all cars consume fuel" and gave me the keys back the next day to disappear in the distance.
If they tested it, it means that this is the fuel consumption folks, and we should be merry because it\'s the merry season and leave the grumbles for the next year.
This is the end of the saga
All the best
Teo
Maybe that\'s the reason that Mazda offer a towbar as an accessory....so you can tow your own fuel bowser:p :p
Great car anyways :wave
... and I used to take the piss out of a good mate of mine who has a Jag XJ12 and two fuel tanks on the car. Now he got his revenge. I\'ll wait and see if running the engine in makes any difference - I am not holding my breath.
You are right about it being a great car - no complaints here. Most of the times when I go round turns I think the G-force is a bit high for such a low speed - until I glance at the speedo and the speed is usually 50% higher than I thought.
It really goes like the clappers, and makes no fuss about it. Maybe the din of the fuel bowser in the back might tell us it\'s going too fast ;-)
Teo
lol
More BHP = more fuel consumption
For a 240bhp car 20mpg during running in is quite reasonable IMHO.
Before I started getting silly cars I had an Integra Type R - DC2 it was a 1.8l approx 25-30mpg the entire time - brilliant.
Most cars I own now do between 5 & 20mpg - pretty shocking really.
I am suprised it says you can push the car so hard during running in period - I wouldnt normally push a car beyond 4,000 if it revved to 8,000-9,000 ish to be honest.
Also let me get this straight you are complaining about fuel consumption at 5000-5500rpm - what does that equate to in MPH? 100? at 100 miles per hour getting 20mpg? thats brilliant fuel consumption, figures I could only dream of for an FD. :D
Anthony.
Cruising in sixth I find that:
Revs Speed
2500 50 mph
3000 60 mph
3500 70 mph
...as the roads seem always to be wet or its night when I get chance to drive my RX-8....I havnt been able to test this
can any body confirm whether
by logical proportional deduct ion...
does
7000 140mph
9000 180 mph
......or does the speed ratio drop
Captain RXb
widn resistance is always the enemy at the top end so yeah theoretical figures are just that (http://www.stopstart.freeserve.co.uk/smilie/balloon.gif)
Si
I have had my RX8 for about 6 weeks. I also think the consumption is high. I believe I am getting nearer 20 mpg. I may be able to get closer to 25mpg but I am not going over 4-4.5K rpm and limiting
my driving style severely. if I wanted to
drive this way I would have bought a
ford focus.
I swapped out a 2.7L Hydundai and am very disappointed with the RX8. If I can\'t get better mpg then I really will reject the car. I will give the garage a chance to improve the situation but then I believe I have a legal right to challenge this situation. The published figures are way out.
Hi PNB,
I am sorry to hear you are not happy with the car.
How many miles have you done in it?
I do not jest but when it is run in it should improve.If you have been doing 4500 revs then you must have been traveling at 90mph in top.
How many services have you had?
When you are near your dealer ask them to check your car over including the spark plugs,some have had them changed and seen immediate improvement.
Also I am not sure about this but we think at a certain service interval early on something is changed in the induction side of the engine that helps too.
Also as has been said in previous posts you have to remember that the RX8 is more than twice as powerful as a typical Mondeo with the subsequent fuel consumption rise.
I hope this helps.
Kind regards
Carl:wave
QuoteOriginally posted by pnb
I have had my RX8 for about 6 weeks. I also think the consumption is high. I believe I am getting nearer 20 mpg. I may be able to get closer to 25mpg but I am not going over 4-4.5K rpm and limiting
my driving style severely. if I wanted to
drive this way I would have bought a
ford focus.
I swapped out a 2.7L Hydundai and am very disappointed with the RX8. If I can\'t get better mpg then I really will reject the car. I will give the garage a chance to improve the situation but then I believe I have a legal right to challenge this situation. The published figures are way out.
Sounds like you would be better off with a 1.3ltr Toyota Corolla if you are so concerned with fuel consumption :spank
All this moaning about fuel is sickening... if you can afford the car, you can afford the gas...
Hi Tony,
I am Hijacking this thread as I know you will see it.
I noticed on the US forum that you are going to use 12a stationary gears?in your 10a peripheral.
I would suggest that 13b ones from the 3rd gen would be better.
If you need some I can get them shortened for you.They are as good as race ones.
Kind regards
Carl
QuoteOriginally posted by Carl
Hi Tony,
I am Hijacking this thread as I know you will see it.
I noticed on the US forum that you are going to use 12a stationary gears?in your 10a peripheral.
I would suggest that 13b ones from the 3rd gen would be better.
If you need some I can get them shortened for you.They are as good as race ones.
Kind regards
Carl
Cheers Carl...! Will drop you an email.
Hi Carl,
I have done about 850 miles so far. That equates to 4 tanks of fuel.
Actually I made a mistake - I said 4-4.5k rpm I meant 3-3.5 I have been limiting my speed to national limits i.e 70mph. The cost of the petrol in not the issue. I do mostly motorway driving - clear roads and therefore should expect between 25-32.5mpg - that\'s the spec.
If there are improvements to be had then it is worth going back to dealer.
I will talk to them now. Thanks
Hi PNB,
I definitely think it will improve.
On the engines I build I get people to run in for 2000 miles.
I know Mazda say\'s diferent on the RX8 but it can\'t hurt and in the long run must be better to as it helps with both power and life of the engine.
Kind regards
Carl
I agree entirely with RE10, bit I didnt want to be the first to say it! :-)
If you want Ford Focus consumption, then .... get a Ford Focus.
The Rotary engine\'s advantage is 230hp from an engine that weighs the same as a 1.3.
That means better cornering and stopping performance (than other cars of the same power). All cars are a compromise, so the fuel consumption is the compromise in this case.
Around 20mpg is good for a Rotary. But lets see a Focus vs an RX-8 around a track.
Again, if you want economy, then I dont think its fair to expect performance at all.
Now there are a lot of 4x4s or RVs or whatever being sold, and whats their consumption, eh? Their owners are obviously prepared to accept the fuel consumption for some reason ( I dont get it personally!), so we drive Rotaries and accept it, for whatever reasons.
We might also accept that the Rotary is not all things to all motorists (yet!).
I think it\'s not whether we can afford the fuel or not - I suspect most of us can, and anyway it\'s probably only around 500 pounds extra a year.
What got my goat was the rather large discrepancy between the published figures and the field test results.
I suppose for our colleague that discovered that two of his spark plugs were not doing their jobs this sort of concern helped.
I also considered rejecting the car, based on the fuel consumption. It\'s such a good car in all the other respects that I saw the true light in the end and repented. I was pissed off though for a while, and even talking to guys in the States where I was for the last few weeks, when I mentioned 19 - 20 mpg they thought it\'s not that good (yes I did translate the figures in US gallons). And the gallon of petrol is under a pound there (1.5 dollars).
And also I like to drive long distance abroad, and I don\'t want to be concerned all the time with where the next fuel tank it\'s going to come from. In the wilder parts of Eastern Europe it can get tight at times.
Great car though, I got again really impressed climbing in it after driving sluggish american cars for a month.
Repentant Teo
Can someone find a motorway, fill up with gas... turn off the traction control COMPLETLY and don\'t exceed 3000rpm as you drive down-wind. You will meet the factory spec\'s easy :D
On the return trip (after filling up and recording miles / gas consumption) drive it like a mad thing...
Then decide if you want factory figures or fun.
QuoteOriginally posted by re10
Can someone find a motorway, fill up with gas... turn off the traction control COMPLETLY and don\'t exceed 3000rpm as you drive down-wind. You will meet the factory spec\'s easy :D
On the return trip (after filling up and recording miles / gas consumption) drive it like a mad thing...
Then decide if you want factory figures or fun.
The figures are NOT factory figures but goverment test figures, following a standard test procedure.
This involves starting the car from COLD driving a simulated urban cycle with speeds between 0 and 30 , averaging 12-15 I think, then continues (on same run) to do extra urban etc, this is done on a rolling road. Then they modify the numbers down to compensate for air resistance etc.
I used to think it was done under best possible conditions - which it isnt, and all the info is available on the web if you look for it. Of course they dont drive the car hard but those figures should be attainable, or almost anyhow.
I do get above the minimum of 18mpg, but cant see how i could get 32mpg.
http://www.vca.gov.uk/faq/fuel.shtm#faq4
I think somewhere an important point sometimes gets missed in this discussion.
We are all getting between 18 and 23mpg depending on driving style etc. Apart from the guy who claims his car was altered and he is getting 27 mpg.
The sense of complaint does not come from the actual mpg as most of us appreciate that a fast, fun car will use up the gas. The issue is that the official test figures are so different from the ones we are getting in practise. This descrepancy is too much to be explained by driving style alone.
My last car was an Astra Coupe Turbo 2L with 187 bhp and 0-60 in 7 secs the official fuel figures were 32mpg on combined cycle. I used to thrash that car and I was getting 23urban - 28 motorway.
Of course the RX8 is a much better car in everyway I am not argueing that for a moment. But the fuel consumption should bear more resemblance to the official figures than it does and there seems no explanation for this.
all the best
Yvonne
I agree with Rob - ths minimum 18mpg
seems very hard to improve upon.
F.Y.I -
......i love putting loads of petrol in my RX8....its directly proportional to the amount of fun you have.....but how much oil are you guys putting in and how often....
...incidentally the super unleaded is more fun to put in as it is more expensive and might make my Rocket Car go faster...
Captain RX8
Yeah - I love those Petrol bills too :confused:
anyway as for oil. half a litre at 800 miles and then another half litre at 1800 miles.
that\'s it so far.
still wish the dip stick was longer or more easily accessable in some way.
all the best
Yvonne
1litre of oil every 2k ish miles or so.
How often are you guys changing the oil (or rather, what is the Mazda service interval). I have only ever topped the FD up once, normally I do an oil change before it has used a significant amount.
PS - 25MPG on Saturday in the FD. It was a long motorway trip at about 3000 rpm the whole way.
Lee
"PS - 25MPG on Saturday in the FD. It was a long motorway trip at about 3000 rpm the whole way."
Was it worth it, how much did you save?
Boredom can kill - hope you took enough breaks on the journey:D
I just used the whole tank on motorway driving and was hopeful that it was better mpg but when I worked it out, it was only 21mpg which is the same as I had before on motorway and the best I seem to be able to achieve.
Yvonne
QuoteWas it worth it, how much did you save?
Well no not really, but I was going with a friend to collect a car and it was still being run in hence the 3000rpm (or just over).
Compared to my normal MPG I saved over £50 on the whole trip, but then as it was all motorway for 500 miles I expected it would be better than my normal 15mpg so its not a real saving. Probably saved abotu 10-15 in reality.
Lee
QuoteOriginally posted by J4P RX
How often are you guys changing the oil, normally I do an oil change before it has used a significant amount.
Oil changes? What lube\' system does the Mazda use? The Norton uses an enviromentally unfriendly total loss oil system like a 2 stroke engine, i.e. the oil is stored in a tank and fed into the engine at a rate of about 1 litre per 1000 miles. Having lubed the bearings and eccentric shaft etc the oil is then routed through the carbs mixing with the petrol/air mix and is then (mostly) burnt off in the combustion process. The number of times ive heard.."your engines a bit smokey mate, is it knackered?\'
So, as a matter of interest, how does the Mazda system work?
Hi Norton,
All bearings are pressure fed through the eccentric shaft which runs on plain bearings.Unlike the Nortons roller bearings.
Oil is taken from the sump to an oil metering pump which varies it\'s rate proportionaly as to how much accelerator is being used.This oil is fed through to the inlet side of the rotor housing.
Oil usage is less than the Norton engine,but it runs at a maximum of 150 to one in proportion with the fuel.
Usage varies with driving habits,with 1 liter per 1000 miles indicating that the engine is tired and the oil contol rings on the side of the rotors are getting worn whch is letting oil into the combustion chamber.
On new engines more oil may be used at first until the engine is run in.
Kind regards
Carl
Thanks Carl, sounds quite similar to Nortons system, variable rate metering pump included. I take it that the \'sump\' is really in effect just an oil tank?, is any oil re-circulated back into it? (it isnt on the Norton).
Hi Norton,
yes the oil also is sprayed into the rotors for cooling and then drains back to the sump from the rotors and bearings too.From there its pumped through an oil cooler and back into the engine.
Kind regards
Carl