Mazda RX8 Real world MPG

[ChrisC85]

I have a similar question, but my 231 2006 RX8 is doing around 13mpg on average around town ... actually my commute is mixed and I'm doing a few miles a day on a dual carriageway.

I push the car a bit, but drive lika a maniac only 40% of the time anyway, I get around 140/150 miles from a full tank ...

As far as i know I should be getting around 170/180 miles from a tank around town ... is that kind of consumption normal and if not what to investigate ?

Thanks
Chris

[otolith]

13mpg is very low. Unless you are doing very short journeys in traffic, I suspect that your catalytic converter may be knackered.

[sherman]

A PH run I ws on last night. I covered 185 miles, used 43 litres of petrol and that equates to 19mpg. The roads were mixed from a long motorway bit to a brilliant B road where I didnt get any higher than 4th gear for at least 15 miles. Was great fun.

[ChrisC85]

I'm suspecting a cat problem as well. I'm going to try a cat clean additive first, see if that does anything, if not I'm planning to replace the whole exhaust, filters, plugs and chip it anyway ...

If anyone has more ideas / experience let me know : ) I will let you know if using a cat clean did it any good.

BTW. 17/18 mpg from a fast driven sports car is great ! anyone who disagrees clearly haven't driven comparable sports cars, my mates 2004 3L 3 series beema is doing 10mpg round town and that's still good for that engine. If I'll get 17/18 mpg I will be more than happy with my economy xD

Edited by ChrisC85 on Friday 31st May 12:22

[randomwalk]

For the performance the mpg for an RX8 is rubbish, you get better or at best equal mpg out of a modern V8 with far more performance. I suppose the trade off is the purchase price is cheap so the difference in purchase price would buy quite a bit of fuel.

[otolith]

Trade off is that it doesn't feel like there's an elephant sat on the bonnet.

[Efbe]

randomwalk said:

For the performance the mpg for an RX8 is rubbish, you get better or at best equal mpg out of a modern V8 with far more performance. I suppose the trade off is the purchase price is cheap so the difference in purchase price would buy quite a bit of fuel.

people always seem to bang on about mpg. it's a load of cobblers tbh.

depreciation, insurance, servicing(sometimes) for most people all outweigh the cost difference between 18mpg and 25mpg or even 40mpg, yet because it's drummed into people so much, they use the mpg as their primary purchasing criteria.

I made the horrendously stupid mistake of getting the 1.9TDI version of the Alfa 159. I should have got the 2.2 petrol, but thought the mpg cost would be too high. I do 5000 miles a year. what a plonker!!!

[randomwalk]

Efbe said:

people always seem to bang on about mpg. it's a load of cobblers tbh.

depreciation, insurance, servicing(sometimes) for most people all outweigh the cost difference between 18mpg and 25mpg or even 40mpg, yet because it's drummed into people so much, they use the mpg as their primary purchasing criteria.

I made the horrendously stupid mistake of getting the 1.9TDI version of the Alfa 159. I should have got the 2.2 petrol, but thought the mpg cost would be too high. I do 5000 miles a year. what a plonker!!!

Agree with you. Depreciation is the biggest expense and it would seem the RX8 has almost fully depreciated at current price levels so mpg should not be such a concern. IF the RX8 averages 20mpg and another car averages 30mpg then the cost difference of 10mpg say on annual mileage of 15,000miles will be £1,575 per annum (based on say £1.40/litre).

[tombstone]

I have a mildly fiddled with 231 and roughly 16mpg on my commute (7 brisk miles to work) and have seen a healthy 22mpg on a average run.. I use Vmax and pre-mix oil in with the fuel, current exhaust emissions very clean and healthy ( I gas test my car on MOT emissions machine at work once a month when I change the oil...) Yes there're not great, but giving them the occasional thrash is good for them, so fuel economy will suffer.

[ChrisC85]

Also if someone is buying a sports car and looking at mpg they probably don't want a sports car anyway. For me its all about the fun of driving and rx8 has plenty of that. Powersliding through roundabouts, drifting on wet, good for cornering etc, you know, the fun parts

Also 18mpg is still good .... my 13 is not so good, but there must be something wrong with mine.

[mikey P 500]

17mpg in my old one, on my 40 mold round trip t work and back. this was far lower than I was lead to believe before buying, with many claiming they do nearly 30 mpg on a run which form my experience is just not true.

[otolith]

I saw thirty miles per gallon on a run. Once. Mid to high twenties was fairly easy, though. I was averaging twenty, and that was mostly short-ish journeys on rural roads.

[fernandofan2008]

on average I get 230-240 miles out of a tank. Even if i put the foot down. That was with low compression. i get the car back next week from the rebuild and ill probably get abit more out of it.

[fernandofan2008]

otolith said:

Just for comparison, our Saab Aero does 26-27mpg day to day. We run it on super. The RX-8 just needs 95 RON.

RX8's should be run on premium 99RON, not 95. Anyone who owns one knows that.

[fernandofan2008]

randomwalk said:

For the performance the mpg for an RX8 is rubbish, you get better or at best equal mpg out of a modern V8 with far more performance. I suppose the trade off is the purchase price is cheap so the difference in purchase price would buy quite a bit of fuel.

Since when is MPG a sign of performance? I get 30mpg out of me second car which is a megane. Does that mean its fast or something because its less than say a diesel 1.9tdi??? Dont talk ste like most of the PH forum will you? What if you dont want a big lump of a V8? What if you like rotary engines? What if you want to change gear at 9.5k? What if you want a supremely handled vehicle at £3250 with a full engine rebuild and warranty? I looked at a GT86 and laughed at it. Bought an RX8 instead. Or should I have bought a GT86 because it has better consumption meaning its a better car.....

End of the day if your buying a performance car, you can afford the fuel consumption, oil consumption and maintenance, tax and insurance, otherwise you shouldn't buy one in the first place and live in the real world.

[ChrisC85]

@fernandofan2008 props mate. Did the same thing with GT86, I think it's a brill drivers car though (the 86) I just couldn't justify spending 28k (with extras) on a new car right now. Other than that RX8 which I bought for peanuts instead is great to drive. Can't wait to decat, chip it and change alloys to 17s for some smoother drifts

[otolith]

fernandofan2008 said:

otolith said:

Just for comparison, our Saab Aero does 26-27mpg day to day. We run it on super. The RX-8 just needs 95 RON.

RX8's should be run on premium 99RON, not 95. Anyone who owns one knows that.

Really? I owned one for three years and I didn't know that. Hell, Mazda built it and they didn't know that.

Care to explain the benefits of using higher octane fuel in a naturally aspirated engine with a modest 10:1 compression ratio?

[wolves_wanderer]

otolith said:

fernandofan2008 said:

otolith said:

Just for comparison, our Saab Aero does 26-27mpg day to day. We run it on super. The RX-8 just needs 95 RON.

RX8's should be run on premium 99RON, not 95. Anyone who owns one knows that.

Really? I owned one for three years and I didn't know that. Hell, Mazda built it and they didn't know that.

Care to explain the benefits of using higher octane fuel in a naturally aspirated engine with a modest 10:1 compression ratio?

Mine does feel smoother on it (although that could be placebo I guess).

[fernandofan2008]

otolith said:

fernandofan2008 said:

otolith said:

Just for comparison, our Saab Aero does 26-27mpg day to day. We run it on super. The RX-8 just needs 95 RON.

RX8's should be run on premium 99RON, not 95. Anyone who owns one knows that.

Really? I owned one for three years and I didn't know that. Hell, Mazda built it and they didn't know that.

Care to explain the benefits of using higher octane fuel in a naturally aspirated engine with a modest 10:1 compression ratio?

They didnt know it? Funny how mine has the Mazda sticker on the fuel cap saying 'premium unleaded only'. Clearly Mazda didnt know what they were doing then, eh? Premium unleaded gives better MPG, smoother through the revs and overall better performance from the engine. Dont believe me? I dont care. many owners have found a noticeable difference in all of the above. All you need to do is go on the owners forum and countless owners will tell you premium petroleum gives MUCH better results than standard petroleum.

Right now, many of us are trying Nitro+ and getting slightly better MPG than the standard Vpower. Which is much, much better than standard 95 RON. Might want to go back and rebuy one of these and test it yourself and see how wrong you are, and also how the car has much more to give than standard petroleum.

high octane is a much safer petrol for the car, as it has more resistance to detonation which as you know, is prevelant in high compression engines. Also additives in the premium fuel assist with reducing carbon build up.

Please note this from the owners manual;



Note reccomended fuel 96RON+. 91MON/95RON can be used in emergencies but will reduce performance. Seems like you didnt read the manual and didnt experience its full potential :P

Edited by fernandofan2008 on Thursday 6th June 19:47

Edited by fernandofan2008 on Thursday 6th June 19:49

Edited by fernandofan2008 on Thursday 6th June 19:49

[fernandofan2008]

ChrisC85 said:

@fernandofan2008 props mate. Did the same thing with GT86, I think it's a brill drivers car though (the 86) I just couldn't justify spending 28k (with extras) on a new car right now. Other than that RX8 which I bought for peanuts instead is great to drive. Can't wait to decat, chip it and change alloys to 17s for some smoother drifts

They are a great car, and to be honest the Finance package was a smidge out of my price unfortunatly. but to say its a 2013 car, the interior is lightyears away from the RX8, the handling and performance is pretty equal, but it doesnt have the advantage of 2 extra seats and a big boot.

Its one of those cars I really like, but look and think 'what the hell were they smoking pricing it at £28k!? I wouldnt pay more than £22k new'.