I would like to know roughly what MPG Im getting with my FD3. I know I know I probably dont wanna know lol. But I would just like to know just how bad it is lol. Unfortunately my maths skills are awful.
So I was wondering if anyone could help me work it out.
This info is based on average driving. Some longer journeys. Some short journeys. Some traffic driving. Some driving conservatively. And of course some ragging it. So this full tank has had a good average use.
Here\'s a pic of the fuel guage. So wasnt completely empty. But as far as I was brave enough to empty it and I will probably never let it get this low ever again:-
(http://i19.photobucket.com/albums/b175/carlb4/IMAG0130.jpg)
And my trip computer distance that I havent reset since I last filled her right up:-
(http://i19.photobucket.com/albums/b175/carlb4/IMAG0131.jpg)
Oh if only that trip computer was in Miles. Then 204 miles isnt that bad lol. But I am guessing as it has Km beside it that the trip computer and odometer are still in Km. Eventhough the speedo although still says Km has been converted to MPH.
Then immediately after taking those pictures I was actually at the petrol station and I put in £78.78p of Tesco\'s momentum 99 which was 55.91 litres at 140.9 P/L
Thats about 127 miles, which isnt too bad... youve still got a fair amount in the tank looking at that... as long as your fuel tank isnt full of crap, you should be good to hit the orange light. You can get about... another 30 miles or so if your careful outta that tank, so youd probably get about 150 miles at least outta that much fuel
Right, here\'s the method I\'d use!
First you need to know the number of miles you\'ve driven since you reset the trip when you filled up. There are 1.61 km to a mile, so if you know the number of kms you\'ve done then you divide that figure by 1.61.
In this case
204.2/1.61 = 126.83 miles
From there, you know how many litres of fuel you\'ve put in to the car. In this case 55.91 litres. There are 4.55 litres in a gallon of fuel so to get the number of gallons you divide the number of litres by 4.55.
55.91/4.55 = 12.29 gallons of fuel
To get your mpg you divide the number of miles you\'ve driven by the number of gallons.
126.83 miles/12.29 gallons = 10.31 miles per gallon.
Quite glad I have an RX8 now! That sort of figure is what I get from a track day!
Bloody hell that is bad. I thought 25 mpg was bad from my Subaru lol.
I didnt even know there was an orange light that comes on when low on fuel on this car. Do all Rx7 FD\'s have that? And when it comes on how far roughly would you get with it on? Obviously I would never try it but just in case it ever came to that and I was desperately trying to find a petrol station. lol
Depends how you drive it. Mine ran for... 20 miles of light usage once the orange light came on. There isn\'t anything bad about running it lower on occasion as long as the fuel tank is clean, otehrwise you suck up all the crap, and things start to go wrong from there.
Not sure if all FDs have the fuel light, but an easy way to tell is turn the ignition on, but dont start the car and check what dash lights come on =)
I know that the FD can only max out at about 20mpg on light usage by old ladies xD But the fuel cost is worth the sheer joy of driving the car, every time i get into mine i cant help but go all smiley.
The best way to check your fuel is to drive how you want, and see how long a tank lasts you. I mean, the way i drive, if i can manage on a tank a week im happy =)
And is it normal for the exhaust to pop and bang every now and then? And it stinks of petrol too. But one of my mate says this is normal. And another of my mates says it sounds like its over fueling and that I should get a map check done to make sure it isnt dumping a load of unused fuel in.
Thoughts?
Erm, what mods are you running, and have you had the car professionally remapped?
I know that if you have decatted etc it will mean your car needs a remap asap, otherwise the engine is running lean. On mine, before i stuck my PFC in, it would backfire like mad on every up/downshift, but i do think my plugs are on the way out...
I would get a PFC as a first prio, then go get that mapped at a specialist to ensure you dont break anything...
Well the previous owner put a new cat on it as he always struggled to get it through the emissions test on the MOT. But he said now it gets through. Just. And I dont know if it has been remapped or not. All I know is I believe it has a K&N Panel air filter as a replacement for the standard one. Though I havent actually taken the air box apart to see if this really is present. But what I definately does have is a Baileys Dump Valve. Dont know if that makes any difference. And an HKS cat back exhaust system. Well basically back box. And it doesnt back fire badly. Just say when Im parking up or in traffic and just using light throttle then off again sometimes it just does a lil pop pop. Always at very low rpm after backing off. Not as if its at high rpm going BANG BANG or anything lol.
Might be worth checking wether your odometer measures in km or miles as i know when i changed my speed from km to mph it also changed my odometer from km to miles:Thumbs-up
How would I check this?
drive a predetermind distance in another vehicle then do the same in your fd and see if its the same would be the easiest way
sure when i changed mine it goes to miles to.
take a couple mile drive with a mate both of you reset your counters and he follow you for two miles see that they match up at the end.
if your only getting 10mpg out of a standard car something is not quite right!
Yeah, thats a little low, but if he\'s running rich coz of a badly mapped ecu for his current mods, it would explain the low figure...
Im not 100% sure about this, but it could be a result of the ecu map shoving excess fuel in at low speed, which then pops. I still think the best you can do is take it to a specialist and ask. Its probably nothing, but for piece of mind, and better economy/performance its worth it...
not to hijack the thread or anything but why do people always say dont run low on fuel because you start to suck up all the gunk... i mean, isnt that why the fuel filter is there?
Yeah it is, but why shorten the life of something prematurely, or risk something like that at all w/o a good reason
Ok I shall drive to work as I know this is exactly 3 miles from my house so that will tell me. If it is in miles then my fuel economy actually isnt that bad and not far off my subaru :-) lol
Ok just got back and it is in miles. Thats a relief lol. I know it is exactly 3 miles from my house to my work. And the clock had 0.8 on it where I had come back from the petrol station. And just as I got to work it said 3.8. So absolutely spot on :-)
So now working on the fact that my above picture is actually in miles and not Km what does that mean I am getting in MPG?
bout 18 MPG? Thats about normal isnt it? If thats the case then thats not too bad. Not much different to my subaru. I know that isnt the best comparison and its still pretty bad but still. I am happy :-)
Only problem is what does that mean for the odometer? As I dont know what Km\'s the clock had on it before it was converted to miles so now its going to be difficult to tell. Although its irrelavent anyways as it has had a recon engine put it but still would be nice to have a better idea how many miles that engine has done so I have a rough idea when the next re-build is due. Hopefully with the amount of miles I do I wont need to fork out for a re-build for the entire time I own the car. lol
16.61 mpg:wiggle
I have you clocked at 16.6 MPG from those revised figures, and considering thats overall, i dont thinks thats too bad...
Yeah. And keeping in mind that wasnt to the tank dry. Not even the warning light on or anything. And thats lots of short journeys. More motorway stuff and I may even be able to push that to 18 or 20 mpg lol. Biggest problem for me though is the bloody dump valve. I cant help it I love hearing it so I rev between every gear. If I didnt have that sodding thing I could prob get 30 to the gallon lol. But I love it :-)
I dont have a dump on mine, ive been debating on whether to get one or not, its bad enuff having twin turbos... I managed to eke out a measly 9mpg outta my fiance\'s dads turbo golf, simply coz i loooooooove the dump noise xD
Back to topic, on motorway driving, you may hit mid 20\'s, which is fairly good... I do knwo that you can empty a full tank in under 100 miles if you are a bit heavy-footed
I have just had a great thought that police could come out with if they want to stop speeding. And also to help our fuel economy. Make us all fit dump valves. However instead of the cool dump noise make it make a really embarassing sound lol. Like a fart. Or a camp oo err lol. Then we would all drive so carefully because we dont wanna make the dump valve go off lol
Hah yeah, thats true, but then there\'d be an underground mod scene to get that removed/altered to sound cool again, so its a vicious circle you starting =P
lol very true
Quote from: bigdawg;765516not to hijack the thread or anything but why do people always say dont run low on fuel because you start to suck up all the gunk... i mean, isnt that why the fuel filter is there?
It\'s generally a bad idea to let an FD run too low on fuel because if you corner hard (like on a track or whatever) and the fuel sloshes away from the pickup you suck up a big lump of air, lean out catastrophically and then your engine goes bang. :Thumbs-up This is generally considered a bad thing.
As to working out MPG figures, my advice would be.. don\'t. You\'ll only upset yourselves :rollin
Quote from: Nik da Greek;765566It\'s generally a bad idea to let an FD run too low on fuel because if you corner hard (like on a track or whatever) and the fuel sloshes away from the pickup you suck up a big lump of air, lean out catastrophically and then your engine goes bang. :Thumbs-up This is generally considered a bad thing.
As to working out MPG figures, my advice would be.. don\'t. You\'ll only upset yourselves :rollin
unless you build a little box inside your fuel tank so if you do corner hard that wont happen ;)
Yep, unless you do that :yes. Of course, arguably the sort of people who are worried about how to eke out the longevity of a fuel filter don\'t always spend huge amounts of time fabricating baffled fuel tanks or custom pick-ups to be fair, but I never implied that it wasn\'t possible. ;)
Was just speaking to the previous owner about the speedo conversion to MPH and he thought it was just the speedo too. He didnt realise that the trip meter had been converted. To be fair though on my little test drive earlier I forgot to look to see if the odometer went up the same. I assume it would though. And with that in mind I asked him when the speedo conversion was done to try to get an idea how many miles its done since. He seems to think it was done on the last engine rebuild at 100,000 Km It now has 118,000 something on the clock. So would that mean it has done 18,000 miles since the engine rebuild?
Quote from: carlbrainiac;765578Was just speaking to the previous owner about the speedo conversion to MPH and he thought it was just the speedo too. He didnt realise that the trip meter had been converted. To be fair though on my little test drive earlier I forgot to look to see if the odometer went up the same. I assume it would though. And with that in mind I asked him when the speedo conversion was done to try to get an idea how many miles its done since. He seems to think it was done on the last engine rebuild at 100,000 Km It now has 118,000 something on the clock. So would that mean it has done 18,000 miles since the engine rebuild?
Yep, sounds like it. My speedo is converted to miles and the odo works in miles now too
Afaik, the odometer stays in KM, which is why when you see the cars for sale, even after being converted, they give it in KM and Miles, but i could be wrong...
Guess i was wrong, oh well, live and learn xD and man its a steep curve =P
Next time I go out for a drive I shall also keep a close eye on the odometer to see if it goes up the same as the trip meter. If it does then I know its in miles now and no longer in Km. I would assume if the speedo and trip meter has been converted then surely the odometer should be as well.
Quote from: carlbrainiac;765586Next time I go out for a drive I shall also keep a close eye on the odometer to see if it goes up the same as the trip meter. If it does then I know its in miles now and no longer in Km. I would assume if the speedo and trip meter has been converted then surely the odometer should be as well.
Assumption correct, all readings will now be in miles. So if the conversion was done at 100,000km, the same time as your engine rebuild, your engine has done 18,000 miles. Total car mileage is 100,000km + 18,000 miles = 80,140 miles.
nice one cheers
when i had my satin black fd i was averaging about 14mpg, i actually took the time to work it out once - and regretted it !!!!
Quote from: Dehs;765583Afaik, the odometer stays in KM, which is why when you see the cars for sale, even after being converted, they give it in KM and Miles, but i could be wrong...
Guess i was wrong, oh well, live and learn xD and man its a steep curve =P
It is not unheard of that unscrupulous poeple may do this because either they dont know how to work out if the car is clocking up in miles or km or prob more commonly they do know it does count up in miles, but if they quote in km\'s makes it look like the car has been used less.
Quote from: Nik da Greek;765566...and then your engine goes bang. :Thumbs-up This is generally considered a bad thing.
HaHa.
We have a Genuine scientist within our midst :p
When I had my FD, single turbo (GT35R) street port and v-mount setup I once got 24mpg going from Bristol to Southampton. I was rather pleased with that :)
do jdm models have different size petrol tanks as mine cost me £101 to fill up the other week from empty, that was with v power at £1.42 pl lol so £75 seems like a bargain to fill up to me.
Quote from: FD Dave;765700do jdm models have different size petrol tanks as mine cost me £101 to fill up the other week from empty, that was with v power at £1.42 pl lol so £75 seems like a bargain to fill up to me.
My tank wasnt completely dry when I filled up though as seen in my pics. So Im guessing as I put in 55.91 litres that must mean by how much I had left on the needle and the fact the warning light had not yet come on that maybe its a 60 litre tank?
The first time I filled it up it cost me £80 something but that was at a different petrol station obviously near to where I brought it from. Cant remember which one it was though. So guessing that could have been either higher price fuel there or the tank was dryer than what I allowed it to go to when I brought it off the previous owner
Quote from: FD Dave;765700do jdm models have different size petrol tanks as mine cost me £101 to fill up the other week from empty, that was with v power at £1.42 pl lol so £75 seems like a bargain to fill up to me.
No, he just had more fuel left than you did... Tank is 70 or 75 litres IIRC
Well I could tell you how I get the milieage from my FD as illustrated in the pic and retain good performance but you won\'t like it! I only fill up with 95 RON as well.
(http://i154.photobucket.com/albums/s257/bimbleuk/Misc/MPG_Calculation.jpg)
justin you seriously getting 400 miles a tank!?
Still in km, and running some kind of piston monstrosity, or single turbo driven like a granny... Yep, don\'t like it!
I\'d never even thought about mpg on my FC I remember it was bad on my old egi I used to drive a sub 20 mile round trip to work and it would cost me £10 and that was like 2 years ago when petrol prices weren\'t so bad!!
What are people with (fairly) stock TII\'s getting?
Quote from: RobMatthews;765811justin you seriously getting 400 miles a tank!?
That\'s what the fuel gauge is indicating and my odo is accurate as I\'m using a programmable conversion box on the gerabox output and I\'ve verified it on GPS etc. I\'ve fiiled up to half with 32 litres previously so the gauge appears accurate to at least half anyway.
I\'m only driving the RX now as I cycle quite a bit anyway so was silly to have two cars (other is a 106 TD) on the road. That\'s mixed driving to work and out n about this weekend no motorway but some dual carriageway.
This is not uncommon from what I\'ve seen posted on another forum.
400miles isnt that extreme, ive managed 450miles to a tank, but that was 99% motorway driving, its all about how you map your vacuum areas
Quote from: turbotoaster;766035400miles isnt that extreme, ive managed 450miles to a tank, but that was 99% motorway driving, its all about how you map your vacuum areas
I certainly wouldn\'t claim it\'s like a diesel but it\'s at least reasonable enough to let me drive the car most days. Like any RX it will quite happily burn fuel as fast as you can fill it when using it how it was designed!
Surely mapping for fuel economy though takes away the whole point of the car I.e performance though doesn\'t it?
Quote from: carlbrainiac;766214Surely mapping for fuel economy though takes away the whole point of the car I.e performance though doesn\'t it?
I believe Turbotoaster has spent time mapping part throttle for lean mixures as you\'re not on the gas but merely cruising. Often cars are tuned on the rollers for full throttle power runs and part throttle load sights are neglected.
Sounds good. So why don\'t we all do this? Too exspensive?
Quote from: carlbrainiac;766273Sounds good. So why don\'t we all do this? Too exspensive?
its very time consuming to be fair.
and if your paying someone to do it, then it works out expensive.
i do all my vacuum tuning when i was on my way to work, or to the shops or on the motorway to give myself something to do.
i regular hit an average of 28mpg over a journey, i think blitz said hes had his over 30mpg when he was running low of fuel once
it does make a big difference in your mpg figures and i think the money i saved in fuel easily pays for the wideband kit i bought.
I mentioned this on another forum and said most tuners will tune the full throttle, idle and a little bit of part throttle....they wont tune perfectly every cell on the map as it takes forever.
I still believe this to be the case, but it created mayhem, a thread was made about me and i was accused of calling all tuners crap by it which i never said, and infact praised 2 tuners.
My rx7 was a daily driver so it was worth me doing......if i only used it once a month for a midnight blast then i wouldnt have bothered.
If anyone wants to get into basic rx7 tuning then it really isnt that hard, i was expecting it to be alot harder that it is, but up to yet its been a walk in the park and im running 20psi of boost on non-seq twins
Sounds like you\'ve done a good job to me, well impressed.
How come Grinder hasn\'t posted on an MPG based thread?
Someone summon the tight arse!
So how do you actually do the tuning? Especially on while on your way to work etc? lol. I dont understand. Do you permantly have a laptop connected to it to see what its doing as you drive and adjust accordingly till you get your desired result? In which case surely the software/kit is exspensive? If it was so simple I really struggle to see why more people havent done it. Could be a good tip for all thirsty cars not just Rx\'s
a wideband kit is £140, as long as you have a power fc commander, thats really all you need.
well to make it very simple ill try to explain it.
say for example you travelling along at 60mph and your wideband says your AFR is 13.5
now you know that the higher the number the leaner the mixture is, so you set yourself a target afr of 14.5
now 14.5/13.5= 1.07 or 7% more fuel than you need.
you then adjust the fuel map by -7% at that point, then look at your wideband to see if it has done the desired effect.
obviously before everyone jumps on me im just trying to think of a way of simply saying it so i know the numbers arnt exact and you have to take in consideration the map points around the plot and blending the transition
most of my vacuum tuning was done on my commander as you dont have to worry about running to lean and popping your engine so you can spend time fiddling to get it spot on.
infact alot of my boost tuning(including up to 20psi) was done on the commander as i learnt to be able to get around the unit pretty fast in the end, you just have to have a good memory so you dont forget stuff while your flickign between screens.
I believe that i could teach someone to map there fuel tables on there own rx7 with a few hours of work, obviously ignition timing takes longer to teach.
Interesting but I have no idea what AFR is nor a FC commander. lol. Means nothing to me. You might as well be speaking another language. I guess I\'ll leave as is for now and if the fuel keep disappearing really starts getting me down then I may re consider. But being that I also have a Subaru means I can split my journeys between the two cars. And also being that I own a subaru Im kinda used to regular trips to the petrol station lol. I\'d start getting withdrawl symptoms if I didnt go to the petrol station for a while. Its like a second home to me now lol
AFR = Air Fuel Ratio
13.5:1 means for every 13.5 litres of air the engine is getting 1 litre of fuel........its a basic ratio.
a common ecu for the rx7 is a apexi power fc, they come with a unit(looks like a gameboy) called a commander, it shows all the data that the ecu sees, like water temperature and revs.....you can use it to change 90% of what the ecu does(including changing fueling)
Yeah, carl i seriously reccomend getting an Apexi Power FC ECU and Commander. They are a large setback cash wise, but keep an eye on here, as you can regularly get 2nd hand ones for about 450 quid. In fact there may still be a couple in the sale section kicking around. I learn a little about the mapping process for setting the basemap on mine, took me about... 4 hours of researching to get the gist, but i wouldnt dare try it on my own yet xD, im just too scared of breaking my baby.
Heres the link to a basic knowledge and faq, with links to higher reading if you care to take it that far mate. Its definately worth a read, and is really interesting (PS: if posting this link isn\'t allowed, im happy to remove)
http://www.rx7club.com/showthread.php?t=573647
Once i get mine to a stage where im interested in fuel economy, i may contact you for more info toaster, if thats ok?
Oh right cool. How much are those ECU\'s? And what other benefits does it give? And is it a job you can do yourself to install it? Or is it a specialist thing?
Sorry I started to write that post before I realised you was going to put that previous post lol.
Thats a bit rich for me to be honest. I dont wanna end up spending too much on this car as its just a toy. Im not sure if Im gonna own it long term as at some point I gotta start thinking about getting my own place. At which point Im prob gonna have to sadly sell up on the rx7 and the subaru and get some boring but super efficient hybrid so its super cheap to run just so I have money to get my first place and survive. lol.
Guessing i just pipped you to the post there carl =P
Installing it isnt really that hard. Its a few bolts, and clips, and on mine i had to modify the bracket a little, but it wasnt much work. I highly recommend reading that FAQ as it answers all your questions =)
EDIT: Aye, its a bit of a money sink for sure, but you can seriously damage your engine if its running mods on a stock ECU, as you run lean and pop... there goes £3000 on a rebuild.
And hybrids are naff, get a diesel, better mpg by far!
Prius gives like... 20-40 mpg or something, and even the rex can give that much according to toaster xD
To be honest I dont wanna read it now as I dont wanna know what Im missing out on lol. I just cant justify throwing all my money into this car when I know when I sell it I wont make that money back
True. But also in any case Im not really running any serious mods. Just basic stuff. Standard Panel air filter (I think) Dump valve. And Cat back Exhaust. I have done that on the Subaru minus the dump valve with no changes to ECU. I could understand if I had loads of mods and did loads under the bonnet. But if I had and I had that kinda money to burn then I prob wouldnt mind spending out on ECU upgrade
Thats fair enuff, from what i\'ve read theres a fair bit of discussion on whats able to be done to the car without needing a remap... *shrug* mine has had quite a fair bit done, so it was kind of a necessity for me. Luckily i got my ecu off the guy i bought the car from, so was a win-win xD
Quote from: Dehs;766346Yeah, carl i seriously reccomend getting an Apexi Power FC ECU and Commander. They are a large setback cash wise, but keep an eye on here, as you can regularly get 2nd hand ones for about 450 quid. In fact there may still be a couple in the sale section kicking around. I learn a little about the mapping process for setting the basemap on mine, took me about... 4 hours of researching to get the gist, but i wouldnt dare try it on my own yet xD, im just too scared of breaking my baby.
Heres the link to a basic knowledge and faq, with links to higher reading if you care to take it that far mate. Its definately worth a read, and is really interesting (PS: if posting this link isn\'t allowed, im happy to remove)
http://www.rx7club.com/showthread.php?t=573647
Once i get mine to a stage where im interested in fuel economy, i may contact you for more info toaster, if thats ok?
i paid 450 for mine, your more than happy to ask me as many questions as you like, i love sharing any info i learn because when i first got one it was hard to get info out of anyone as everything was very secret squirrel(especially mapping)
Quote from: carlbrainiac;766347Oh right cool. How much are those ECU\'s? And what other benefits does it give? And is it a job you can do yourself to install it? Or is it a specialist thing?
takes 5 mins to fit, couple of screws to remove and install, cant go wrong really.
it has many benefits, more power, better economy, change the temps the fans come on, you can monitor alot of the engine parameters to keep it safe
Thanks TT, i\'ve had to put my rex on hold for a bit and get my daily driver back on the road, but once thats sorted, ill be in touch =)
Yeah but still thats a lot of money. And I have been down the whole modifying car route before. And I know no matter what you do to it. You never get that money back. It adds no value what so ever. I know the RX7\'s are almost an appreciating classic. But its going to get to the point where they will only be worth anything if they havent been too molestered. People like originality and reliablity. (I guess I watch too much wheeler dealers) lol. But yeah if money was no object and I knew I was keeping the car as a long term investment then yeah would probably consider it. But I just dont know how long Im gonna have it and if I dump a load of money into it then sell it and make a massive loss then I have dipped too far into my savings to have any hope of owning my own place before Im 40 let alone 30 lol. Im 26 now. Its bad enough Im STILL living at home. lol.
Tune it, no one lives for ever. I\'ve sunk waaaaay more money than it\'s ever worth into my RX8 and I\'m not going to see it again but then again I\'m not going to sell it and whilst it\'s subjective I reckon the money I\'ve spent is well worth it for the fun I have.
Thats fair enuff mate... However, if you get the ECU for about 450, you will be easily able to resell it for that much, s\'long as its still working, same with some of the other mods, if you buy the 2nd hand, you can generally get the majority of the cash back if you strip it down before you sell.
Will, im with you, but im not intending to ever sell my rex, *crosses fingers*. For carl, its just a big toy for now, so i can see his point in not wanting to spend out what he cant get back...
Found out today whilst comparing exhaust sound with a mate that my exhaust flames and bangs loudly where I\'m up at the rev limiter lol. Don\'t worry im not a chav so not gonna make a habit of doing it. Though I might be tempted to wait till its dark and do it again to get a video on my phone lol. Never had a car that\'s flamed before
Here\'s the video taken on my mates phone while we were parked up at work. Havent done one at night yet. Dont know how confident I am to try and make it flame again lol. Dont wanna damage the engine. Looks cool though. lol
(http://i19.photobucket.com/albums/b175/carlb4/th_VIDEO0021.jpg) (http://s19.photobucket.com/albums/b175/carlb4/?action=view¤t=VIDEO0021.mp4)