Sooner or later someone has to start the inevitable MPG thread - so might as well be me!
My first tankful, and 22mpg. Not as good as I hoped, but that should get better as the car loosens up. A lot of motorway, a lot of D.C. with roundabouts, a bit of pootling around town and plenty of traffic jams. Also a lot of stop - start and idling at the request of friends who want to hear the engine! And not a hint of flooding...
I'm not going to get upset by any particular average but it might determine how long I keep the car, ie 2 years, 3 years, 10 years....

JH

Compared to the US threads on MPG, I think the results for your tankful are very encoraging and augers well for the future. It certainly boosts my confidence about the car and I would expect your results to improve.
If I get 22mpg on my first tankful I shall be well chuffed!:) :)

Keep us informed on the next few tanks.

Cheers

thepenn

Sorry, I forgot this is a European forum... I should add for our friends on the continent I think that works out at 12.9 litres / 100km.

Originally posted by Jon H
Sooner or later someone has to start the inevitable MPG thread - so might as well be me!
My first tankful, and 22mpg. Not as good as I hoped, but that should get better as the car loosens up. A lot of motorway, a lot of D.C. with roundabouts, a bit of pootling around town and plenty of traffic jams. Also a lot of stop - start and idling at the request of friends who want to hear the engine! And not a hint of flooding...
I'm not going to get upset by any particular average but it might determine how long I keep the car, ie 2 years, 3 years, 10 years....

JH

That would be 18.33 miles/US Gallon - right in line with the poll taken awhile back.

22mpg would suit me. :)

rael

Still haven't worked mine out....

Ok just dug out my receipt.

Did 139.6 miles from full to full.

Total petrol was £21.50 @ 74.9p per litre, 28.71 litres then, which divide by 4.55 to get gallons gives 6.309 gallons.

139.6 / 6.309 = 22.13 mpg for first bit of tank.

I'd be quite happy with that for my first run renegade:) :)

Just hope it gets better.

Cheers

thepenn:)

What's wrong with 22 MPG? That's pretty good in my books.

Rotary engine runs rich in cold startup so driving more highway and less stop and go will dramatically improve mileage.

I get 13-14 MPH for all city driving. I get 20-21 MPH for highway on my RX7 twin turbo lightly modified to 280 hp.

right so here's the next tankful....

184 miles, 42 litres. 19.93 mpg in the end. However, this DID include sitting in traffic moving 5 miles in over an hour on the A404 yesterday evening trying to get to the M40. So I'd reckon that this tank would be even better.

364 miles on the clock at the mo.

I've done 75 miles from full and it's on 3/4

I reckon I'm gonna get about 250 ish

What petrol are you guys putting in your cars?

95 Ron

Cheapskate!!!!

97RON and Optimax.

I'm another cheapskate, have used 95 so far. Will bite my lip and try 98 (Optimax) in a couple of tanks once the car has settled down.

As per revhappy's comments, european gallons are different from "real" (american) gallons. And what the heck is "chuffed?" Is that a bad thing?

chuffed = happy :D

Stu C

Originally posted by 8_wannabe
As per revhappy's comments, european gallons are different from "real" (american) gallons. And what the heck is "chuffed?" Is that a bad thing?

Chuffed in this context is happy but in another situation it means fart / toot / I have flatulence!

toot? I have tooted? Dialects eh.


next tank (well 136.9 miles) was 23.1 mpg... motorway at 90mph for most of it...120miles ish

Originally posted by renegade_si
toot? I have tooted? Dialects eh.


next tank (well 136.9 miles) was 23.1 mpg... motorway at 90mph for most of it...120miles ish

I put it in cos a guy I knew from Kansas called it a toot!

Beans , beans the musical fruit , the more you eat the more you toot.......:p

Originally posted by 8_wannabe
As per revhappy's comments, european gallons are different from "real" (american) gallons.

Excuse me. The offical gallon is the British Imperial Gallon. Johnny foreigner in Europe uses that new fangled metric nonsense.

You Yanks should be using the imperial gallon, but when your forefathers were going over on the Mayflower, they didn't have the sense to put a lid on the standard weights and measures, and some got spilled.

Thats why the US gallon is only 0.8327 Imperial gallons, and you get such poor MPG.

Cheers
---Dave

P.S. For the benefit of merkins ;)

Dave - you always crack me up. A Smiley at the end of your posts means that irony is not lost on people.

bugger almost forgot ;)

First tank 21.8MPG (real Gallons, not this USA tosh.... ;) )

Mainly A/B road stuff , very little motorway.

M.

I would like to thanks JonH, as he is the only one not to have forgotten it's an EUROPEAN forum :)

13L/100kms seems flawless, as it's a regular figure for a sport car.

And Dave - I support you on this one, Yanks always forget there was something before XVIII s ... but, hey we appreciate you guys :)

Stephan

1st tank 23mpg.

light on from full at 261, filled up at 275, 53.3 litres, 23mpg I believe.

Some motorway, mostly quick A/B roads with running in sport driving.

Second tankful, exactly 22mpg again, based on 225 miles. (12.9l / 100km over 363km). That was a mix of mostly motorway, with other open roads and NO town driving. Got a feeling thats going to be my average unless there is a change after a few '000 (or cold weather hits it hard).
By the way is a US mile any different from a UK one?

2nd tank - 24mpg.

1st Tank

17mpg, but been caning it!

Originally posted by Contigo
17mpg, but been caning it!

:norty:!

Guess your into the stig way of running in then....

My very first tank full has returned an unbelievably good 26.2mpg :D

240 miles of that was a motorway trip taking it pretty gently on the way up, an very gently on the way back in thick fog. So I'm probably not going to see that on the daily commute, but it is still impressive seeing that the other 26 miles, were quite a bit less restrained.

I really did try to keep the revs down, honest, but it was impossible to resist quick blasts up in to the rev stratosphere, especially with someone else in the car.

I've hit the rev limiter in two gears accelarating on an up hill ramp to the bypass. I couldn't hear the buzzer, and the renesis gives no indication that it is running out of power at almost 10,000rpm.

I am going to be careful not to do that again, and keep it under 7000 as it says in the manual. But the renesis spins up in a blink of an eye, making it oh so difficult!

Cheers
---Dave

I kow, vey bike like revving, I'm trying my best to not rev past 7k...

Commute to work didnt give me any real opertunities to open her up some.

Originally posted by RobDickinson
:norty:!

Guess your into the stig way of running in then....

Don't see the need with modern engines. I ain't been caning it from cold, its just common sense.

I love driving this car and can't keep it below 4k revs.

I need a new pair of tyres on the back already!

I'm not sure you can actually cane it immediately from cold. I started up, left it about 10 seconds, then blipped the trottle to let my father hear the sound, and the rev limiter came in at just over 6000rpm. Left it a few minutes to warm up (and so it wouldn't flood), and after that it spun up all the way.

Cheers
---Dave

Yeah Druck, it limits RPM when cold. But Its probably still better for the engine to treat it nicely until properly warmed up.

600miles isnt that long. 415 on the clock now.

Just been out for a drive at lunch. "raced" a bik round a roundabout/onto motorway. ended up cruising at 90, he then shot off like I was standing still. :)

I did a particularly nice drift with the tail slighlty out (DSC still on) coming off a roundabout at lunchtime. It has a particularly poor surface for grip, so hopefully not to bad on the tyres - if I get into that habit, I can see myself needing new tyres at around 1000 miles!

Cheers
---Dave

Do not spank a rotary from cold.
It is the law.(and yes , 6,000 rpm is spanking it when cold)

You have been warned.....

Dont worry, I just reved it cold once, wouldn't dream of trying that moving. I couldn't get it up to 6000rpm in first half mile from the house without seriously changing the law of physics anyway!

Cheers
---Dave

Originally posted by druck
My very first tank full has returned an unbelievably good 26.2mpg :D

240 miles of that was a motorway trip taking it pretty gently on the way up, an very gently on the way back in thick fog. So I'm probably not going to see that on the daily commute, but it is still impressive seeing that the other 26 miles, were quite a bit less restrained.

I really did try to keep the revs down, honest, but it was impossible to resist quick blasts up in to the rev stratosphere, especially with someone else in the car.

I've hit the rev limiter in two gears accelarating on an up hill ramp to the bypass. I couldn't hear the buzzer, and the renesis gives no indication that it is running out of power at almost 10,000rpm.

I am going to be careful not to do that again, and keep it under 7000 as it says in the manual. But the renesis spins up in a blink of an eye, making it oh so difficult!

Cheers
---Dave
Dave that was impressive, I cant get near that with mostly motorway driving (limited to 70-80 by the weight of traffic on the M1). Were you in 6th for all that, or did you cruise in a lower gear? I tend to get it in 6th as soon as I can most of the time (being resigned not to be able to enjoy myself because of all the traffic), and am wondering if a lower gear is actually more efficient. Also did you have DSC on or off?
JH

I find I can drive the car easily using the lower half of the gear box almost exclusivly (2nd, 4th, 6th). Its Just at the moment , I'm choosing not to :)

This tank is mainly Urban and short sprint. past 1/4 and only 200miles , gona be low :O

Originally posted by Jon H
Dave that was impressive, I cant get near that with mostly motorway driving (limited to 70-80 by the weight of traffic on the M1). Were you in 6th for all that, or did you cruise in a lower gear? I tend to get it in 6th as soon as I can most of the time (being resigned not to be able to enjoy myself because of all the traffic), and am wondering if a lower gear is actually more efficient. Also did you have DSC on or off?
JH

DSC on and in 6th gear most of the time, dropping to 5th to overtake (resisting the temptation to use 3rd). Was going about 85-90 on the way up, but it really was foggy on the M42 on the way back, so kep it down to around 50 to 80. Thats probably where the good MPG came in.

But remember that was a single tank calculation, and you really need to average over serveral fill ups, as different pumps will start cutting out at very points, and its then up to your judgement to cram in the last few litres. Unless you fill until it starts spurting out of the top, there could be a considerable difference.

However its not looking like I'll get anything near that figure commuting to work, and taking it out for a blast each lunctime - even though I'm keeping it under 7000rpm (most of the time) until 600 miles. After that I'll be grateful for anything in the 20's!

Cheers
---Dave

Originally posted by druck
But remember that was a single tank calculation, and you really need to average over serveral fill ups, as different pumps will start cutting out at very points, and its then up to your judgement to cram in the last few litres. Unless you fill until it starts spurting out of the top, there could be a considerable difference.

However its not looking like I'll get anything near that figure commuting to work, and taking it out for a blast each lunctime - even though I'm keeping it under 7000rpm (most of the time) until 600 miles. After that I'll be grateful for anything in the 20's!

Cheers
---Dave

I'm caculating my mpg on pump display fed litres and odometer miles, which may not be 100% accurate as said.

2nd tank - standard cheapy 95ron.

230 miles, 51 litres till full.

Works out to 20.5 mpg.

Was 100% urban and lunchtime sprint, all below 7k rpm, miles on the clock now 530.

Urban cycle is supposed to be 18-19 so I cant realy complain, unlike my bank manager :)

3rd tank is optimax again.

Just filled up another tank after some more normal commutting driving, and quite a bit of lunchtime spins. Only did 220.5 miles before it was close to empty, so I was expecting the worse, but bunging the numbers in I see its quite a respectable 23.5mpg.

Thats also bang in 5quid a week more than my what was getting from the MX3, so what a bargin for the extra enjoyment.

I am still taking it quite easy, I'm sure when I'm making full use of the rev range I'll be down in the 22's.

Mostly gentle "running-in", few lapses of concentration so to speak. Not a bad 23.2mpg though.

Looking at those figures I found out I've been a complete dunce. When I calculated litres to gallons at work I dived by 5.545 instead of 4.545 :eek:

That makes quite a big difference in the bad direction:

1st tank: 21.2mpg
2nd tank: 19.3mpg

Which means I'm going to have to go without food at least one day a week :(

Sorry if my cockup gave anyone unreasonable expectations.
---Dave

Dave! How could you??? I was even switching off my engine on downhills to try and match your figures!! You gave me false hope! So it looks like 22mpg is a reasonable average then. Although I still see threads on the USA / Oz forums that suggest it might get better at higher miles.

Sorry, I am a complete muppet.

Originally posted by renegade_si
Ok just dug out my receipt.

Did 139.6 miles from full to full.

Total petrol was £21.50 @ 74.9p per litre, 28.71 litres then, which divide by 4.55 to get gallons gives 6.309 gallons.

139.6 / 6.309 = 22.13 mpg for first bit of tank.

This is amazing - but wrong. Sorry. :)

There are 3.785 litres/gal, not 4.55. This gives you a total of 7.58 gallon used, for a grand total of 18.4 MPG. This is nothing to sneeze at either. Congrats!

For a great source of online unit conversions (http://www.onlineconversion.com)

VelocityRed8 You use US gallons, we use Impreial gallons. One of ours is worth 1.201 of yours.

Not thaty I am in the positiion to lecture anyone about numbers at the moment :(

VelocityRedRX8........Yes we've got BIGGER gallons but would much rather be paying what you pay per gallon even if they are smaller gallons.

We pay roughly $1.27 per LITRE over here!!! That's about $5.70 per UK gallon ( roughly $4.80 per US gallon)....and you guys are upset about the MPG from the car!!!!!!!!!!!!!!

Cheers

Doogy

Hi Folks

I am a newbie at this, 1st post and eveything.

Got my RX8 a week ago and have done 700 miles since.

Upto the 600 mile mark I was averaging about 23.5mpg but now I have started hitting the (very quiet) rev warning I'll keep you posted.

BTW BigGrin is what I have now I got my 8 :D

Big Grin,

Nice to hear from another new RX-8 owner.

You now need to join the happy band over at the RX-8 owners club (http://www.rx8ownersclub.co.uk/) to get even more benefit from your car and to increase the size of that grin.

.....thanks Guys for putting Velocity RedRX8 right in my absence. Thats why I showed the worknig out, so that someone could question/confirm my maths.

I mean, a first class honours degree in it doesn't mean I can add up, quite the reverse!

Si

:)

Good shout Harrizone - welcome Big Grin, and hope you join the gang on the owners club forum.

I've got 20.8 mpg (225 miles from 49.2 litres) from my first tankfull, but this may not be very accurate as it was originally filled by the dealer so I don't know whether it was filled to the first click or if they squeezed some more in. I assume this was with 95 RON (it's now got Optimax in).

I am largely keeping below 5000 rpm, but within that limit I am still doing a fair bit of hard acceleration. There was also some motorway driving at 80-90 mph in 5th and 6th (trying not to keep at constant revs for too long).

I've notived the fuel gauge is very odd - it starts off moving slowly and seems to accelerate as it approaches empty. I think there is lots of fuel left when the warning light comes on.

My 1st tank warning light came on at 261, filled up at 275 with 53.5 litres, tank holds 61 litres. @ 23mpg that left me with (7 *.22 = 1.5 gallons = ) 34miles until REALY empty. The way the fuel tanks are setup, I hear, it doesnt do realy empty, it'll stop short.

Depends on how much I/we squeeze into the fuel filler pipe too I guess.

Just this minute filled up and thought I would work out the damage.

137.4 miles on 33.86 Litres = 19mpg !!!!!

Car has done 770 miles and yes I have been exploring the top of the rev range.

Forget the consumption, definitely more smiles per mile than any other car I've had.

If it makes any difference I have been using Optimax from day one.

Previously in my Alfa I felt that Optimax was giving me an extra 1.5 - 2 mpg.

Haven't tried my 8 on regular fuel yet.

How much more per litre is optimax? If it took you from say 19mpg to 20.5mpg that would only be worth it, if it was less than 6p more than premium.

It would also take a number of months of running to gauge such a small mpg difference accurately.

Cheers
---Dave

Originally posted by druck
How much more per litre is optimax?

For me , usualy 77-78p pl. ompared to 73ppl for 95.

In my focus , after 3 years of ownership I knew what miles I should get. Optimax got me 10% more, and the car ran far better, for 5-6% more cost.

So far I'm not convinced on it for the 8.

Interesting observation Rob. Would be interested to know if the 8 runs better on Optimax.

Just recently tried in my GTi and there felt to be an improvement overall, but may just be auto suggestion.

Why is it that your old car seems to run better than ever just before you replace it???????????

Got 19mpg on my first tank. Filled her from the garage at 40miles and ran to 250miles before refilling.

Just hit that 250mile mark yesterday and am running on standard 95ron at the moment. Going to try Optimax when I've gone past 600miles and have started to explore the rest of the rev range.

Another update:

I am on tank number seven and I just crossed 1200 miles.
This last tank amounted to 14.8 MPG, which negates the 16.8 MPG of the tank prior.

Still waiting for that magical "ECU Flip". :p

Ahem. this tank = 18mpg.

1st 23mpg
2nd 20mpg
3rd 18mpg.

maniac's 6th : 16.8
maniacs 7th: 14.8mpg

I predict by my 10th tank I'll have to fill up between pumps.

Originally posted by RobDickinson

I predict by my 10th tank I'll have to fill up between pumps.

Indeed.
I expected that my gas mileage wasn't going to be great - it is a sports car, after all.
I wasn't expecting my fuel costs to more than double.
My turbo V6 MX-3 did better than this.
MY 70 DODGE CHALLENGER WITH A 360 AND 3 TWO BARREL CARBS DID BETTER!!! :mad:
My company's 1990 full sized Chevy Van with a 305 does better, also.
It is just absurd...

Maniac is an American, so multiply his mpg by 1.2 to get the UK equivelent.

Cheers
---Dave

I don't see what the issue is with the MPG:

I have a 2 litre Mazda Xedos 6 which is a 144bhp, 172Nm saloon that weighs less than the RX-8 and averages 25 to 27mpg. If guys on here are getting as much as 23MPG with a car like the RX-8 that has 60% more power and 22% more torque (over a wider range) then I think it is a pretty good result.

I was getting an average of 26mpg in my MX3 V6, 130hp 118ft/lb (160Nm), also quite a bit lighter. It had to be driven pretty hard as there is a lot around with more power these days, but it could still hold its own. The RX8 doesn't need to be driven anywhere near as hard - but try telling my right foot that :)

I'm hoping that after a few thousand miles on the clock, I'll manage to keep it on the right side of 20mpg, and anything more will be a bonus.

Cheers
---Dave

Only got 17.51mpg out of my first measured tank! Took it steady as well. Maybe she needs a bit more right foot..............

Hope it improves

Cheers
Oilman

And on that note, has anybody actually noticed any real difference in fuel consumption depending upon whether they're heavy on the throttle or not?

1st tank 1/4 motorway cruse, 3/4 A/B road sprint (within running in).

Rest has been sprint/urban.

Tank1 got me a lot more miles. Either it was the motorway driving, or drive it hard..?

Originally posted by mr_digital_uk
I don't see what the issue is with the MPG:

I have a 2 litre Mazda Xedos 6 which is a 144bhp, 172Nm saloon that weighs less than the RX-8 and averages 25 to 27mpg. If guys on here are getting as much as 23MPG with a car like the RX-8 that has 60% more power and 22% more torque (over a wider range) then I think it is a pretty good result.

Comparing MPG to power torque doesn't really justify it when you consider that I get over 28mpg in my T5 which is 245bhpand about the same torque and weighs a LOT more than the RX8.

All of a sudden I'm concerned about MPG again. A week Friday should tell when I will have gone through at least 3 tanks of petrol! :o

It is a concern and anything over 20mpg looks acceptable based on a more spirited drive. Motorway driving in 6th at 60mph will result in a lot more but is it fun.

rael?

Mine is getting worse as my right foot seems to weigh twice as much now I'm over 600miles, 18.25mpg on my 3rd full tank.

That was taking it very easy for the last 30 miles with the warning light on. The gauge had been showing completely empty for the last couple of miles, and I managed to get 57.4 litres in. Still would have gone another few, but I wouldn't want to risk it.

Cheers
---Dave

Now up to 1700 miles (not bad for eight days) averaging 25.6 miles..... have done about 30% MWay, 40% A&B road and 30% town driving - Am currently quite impressed as I have not been driving like I need a flat cap.

I get £0.14 per mile for business petrol (80% of my miles). I have done some calculations - I need £0.18 to break even. Looks like I need to make a case for £0.04 per mile...

Just a thought but if everyone is so concerned about mpg, what about this.....

the answer (http://www.gastech.org.uk/Frames.html)

:D

Fully expect to get flamed for that :)

Originally posted by Pillman
I get £0.14 per mile for business petrol (80% of my miles). I have done some calculations - I need £0.18 to break even. Looks like I need to make a case for £0.04 per mile...


Surely the ppm is based on engine size? And its a '2.6' according to all the .gov agencies and insurers.


As to conversions. I'll wait for hydrogen, LPG , if/when it gets to popular will have huge tax dumped on it, hydrogen is redily avalable...

Rate per mile for most companies who are paying a car allowance to the employee is based on Inland Revenue figures.

Currently there are 2 figures, 12p per mile for cars up to 1999cc and 14p per mile for cars greater than 2000cc

Your employer can apply to the inland revenue for special dispensation to pay more per mile, but if you are also claiming tax relief for the business miles you do in the car then this just gets subtracted from your relief.

i.e you can claim tax relief for the first 4000 business miles ( i think, and believe me I am no expert ) @ 40p per mile minus what you have been paid by the company.

After 4000 miles the relief drops to 24p per mile ( i think again )

Too much think for one day, time for a lie down.

Originally posted by RobDickinson
Surely the ppm is based on engine size? And its a '2.6' according to all the .gov agencies and insurers.



I am going to make this very same assumption when claiming my tax back for work miles. A 2.6 is worth 63p a mile up to 4000 miles but I can't remember the lower number off the top of my head.

However I may instead use the exact method for next year which takes into account all millage and costs for the year and allows you a proportion back. This may work out better than even the 63p a mile.

I've had to become a bit of an expert in this over the last few years as my company only paid 15p or 10p a mile. I usually got back about 500 to 800 in tax relief from the IR each year

I too get 14p per mile back from my employer which means the car I drive needs to average 24mpg to break even.
I am now upto 600 miles 90% of which has been motorway at 80 - 90. I am getting around 21mpg so I am loosing out each time I get in the car (from a financial perspective only:) ) doing approx 35,000 miles a year is going to cost me dear compared to my old 325ci which averaged 31mpg.

Ed

Originally posted by copperband
I too get 14p per mile back from my employer which means the car I drive needs to average 24mpg to break even.
I am now upto 600 miles 90% of which has been motorway at 80 - 90. I am getting around 21mpg so I am loosing out each time I get in the car (from a financial perspective only:) ) doing approx 35,000 miles a year is going to cost me dear compared to my old 325ci which averaged 31mpg.

Ed

You do know that you can claim back the tax difference between what your employer gives you and the standard 63p or 45p millage rates. So although you still lose out a little you can get some of that money back in tax.

For example, in year ending April 2002 I had done nearly 4000 miles in my GT Four for work at 15p a mile (it was 10p the year before - eek). I got back nearly £500 in tax on the difference between 45p and 15p @ 40%.

This probably didn't pay for my poor mpg but it goes someway to compensate the loss

Ok my mpg observations.

Empty light was on (been on for 20 miles of motoring). Went to the garage and filled her right to the brim (54 litres of SUL =£45)
I drove up north until the light had been on for the same distance.

I did 281 miles
Divide it by 11.65 gals and you get 24mpg.

Not bad at all. I was switching between 80 and 90 and the car is soo smooth in 6th!

First tankful (dealer filled it but probably not to the brim), got 240 miles, so approx 21mpg.

All at 4K revs or less, with mixed driving.

AnilS.

Have to say, I don't know how you guys are doing so many miles per tankful... I did an entirely motorway trip (except for perhaps 20 miles or so) and struggled to get 230 miles up!

Still nevermind eh!

As for the grin factor... haven't properly pushed it yet and am going from an S2000 to RX-8 so A) it'll have to be pretty damn good when pushed and B) am used to revving very highly so it'd better get used to it quick! So far I am getting less miles from the tank than I did in the S2000 and it's costing me £10 more to fill up, so not as happy as I could have been...

Originally posted by RobDickinson
Surely the ppm is based on engine size? And its a '2.6' according to all the .gov agencies and insurers.

With the Renesis you can take your pick of engine size.

1.3 litres by swept volume
2.6 litres by tax, insurance and racing class
3.9 litres by thirst and fun

Cheers
---Dave

Originally posted by AnilS
First tankful (dealer filled it but probably not to the brim), got 240 miles, so approx 21mpg.

All at 4K revs or less, with mixed driving.

AnilS.


This worries me - how bad is it going to be with the full rev range in use??

Also, are people leaving Climate on or off most of the time?