RE: PH Fleet Intro: Mazda RX-8
Discussion
jetpilot said:
The design is actually very efficient, no valves, no camshafts, etc There is rumour that Mazda want to pursue with the rotary but use lasers instead of spark plugs to make them burn cleaner to get through current emissions.
Yep, so fantastically efficient I got a wonderfull 17mpg from mine this month.Not very thermally efficient design, but soooo much fun!
7k for a 3yr 15k miles Mazda approved and warrented performance car. Even if I srove it off Morcambe pier in a couple of years time I would still loose less than other cars I was looking at.
Harji said:
there was a leak from Mazda that they are continuing with Rotary development. The thing is, a Rotary engine is more efficient at converting energy into power than a Piston engine.
Read carefully what I said before ya all fire back to me about MPG figures!
How do you figure that then ?Read carefully what I said before ya all fire back to me about MPG figures!
Given the same calorific value for a given amount of fuel, the resultant work done is less.
I have tried to look at what you said, was it in a different thread ?
Like a lot of us, I've looked carefully at the RX-8 in the past - light, compact, good RWD handling, reasonably quick, quite cheap and a fairly generous 2+2, with the only downsides being the fuel consumption, and some possible engine issues if you're unlucky. It certainly made quite good sense for me at the time, but various family requirements meant I ended up going the family car plus weekend car route instead. The new and much discussed Toyota is one of the few things I can think of that is more or less directly comparable, although the back seats are less usable I imagine...
On the subject of the rotary engine, I do like the concept, in many ways - a bit like my old RD400, it has few moving parts, and makes loads of power from a relatively tiny unit. A bit like my RD, though, it has inherent efficiency issues (I recall old-school two-strokes being referred to as "fuel cooled" engines, only partly in jest). I once had the interesting experience of meeting one Mr K Duckworth (a friend of a friend), who did know a thing or two about engines (although perhaps a bit set in his ways by the time I met him). His point was that the lack of reciprocating mass and so inertial losses was indeed desirable, but the shape and crucially the surface area of the rotary's combustion chamber meant that the thermal efficiency was inevitably low. Thermodynamics really isn't my thing, but that sounds rational to me.
On the subject of the rotary engine, I do like the concept, in many ways - a bit like my old RD400, it has few moving parts, and makes loads of power from a relatively tiny unit. A bit like my RD, though, it has inherent efficiency issues (I recall old-school two-strokes being referred to as "fuel cooled" engines, only partly in jest). I once had the interesting experience of meeting one Mr K Duckworth (a friend of a friend), who did know a thing or two about engines (although perhaps a bit set in his ways by the time I met him). His point was that the lack of reciprocating mass and so inertial losses was indeed desirable, but the shape and crucially the surface area of the rotary's combustion chamber meant that the thermal efficiency was inevitably low. Thermodynamics really isn't my thing, but that sounds rational to me.
e21Mark said:
All I know is that it revs like a mother hubbard and makes a damn fine noise. Even better with a brace of turbos strapped on. If I wanted a super efficient, high miles per gallon, supper efficient whatever, I doubt I'd be looking at performance led coupes.
Not my point and as I have just bought an RX8 I agree but saying the Rensis is efficient is a bit misleading.Mother hubbard revs well ?, cant remember that in the Ryhm.
Old mother hubbard, lived in a shoe
Had so many kids she did'nt know what to do
So got in her Rex and b~@£$%ered off !
As someone mentioned above, the issue is the large surface area of the combustion chamber and resulting loss of heat impacting on the thermodynamic efficiency of the thing. I wonder if materials technology could solve these issues with a rotor housing with lower thermal conductivity - a ceramic wankel engine? Alternatively, BMW has been looking at technologies to scavenge waste heat for electricity generation in hybrid vehicles.
otolith said:
As someone mentioned above, the issue is the large surface area of the combustion chamber and resulting loss of heat impacting on the thermodynamic efficiency of the thing. I wonder if materials technology could solve these issues with a rotor housing with lower thermal conductivity - a ceramic wankel engine? Alternatively, BMW has been looking at technologies to scavenge waste heat for electricity generation in hybrid vehicles.
Its an interesting idea but emissions have also hurt the rotary. Having to burn some oil meant the RX8 entered the top rate of road tax. This plus the low MPG hurt sales badly. Both need answering if its to make a return.However, Its an amazing engine to drive as alows a chassis with a 50:50 balance without resorting to other compromises, has a CofG as low as a boxer and sounds great.
Even though it does less MPG than my old STi and my 3.2 Carrera, Im glad I got one as my daily driver.
Just out of interest I see this thread has been spotted by the good people on the RX-8 owners club: http://www.rx8ownersclub.co.uk/forum/viewtopic.php...
To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
edwheels said:
Just out of interest I see this thread has been spotted by the good people on the RX-8 owners club: http://www.rx8ownersclub.co.uk/forum/viewtopic.php...
To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
Full of defensive simpletons if you ask me.To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
ensignia said:
edwheels said:
Just out of interest I see this thread has been spotted by the good people on the RX-8 owners club: http://www.rx8ownersclub.co.uk/forum/viewtopic.php...
To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
Full of defensive simpletons if you ask me.To add to my previous post which praised the RX-8 over my 3.5 years of ownership, I have to say the owner's club forum was also one of the good things too - lots of helpful, enthusiastic people there who actually 'got' the RX-8!
otolith said:
The tax rate is based on CO2 emissions, which reflect the fuel efficiency. As I recall, the Renesis's figures for NOx, CO and hydrocarbons were pretty exemplary, it was just the amount of fuel being cleanly burnt that was the issue.
My mistake. Thought it tipped it over into the highest bracket.I suppose the rotary's competition is going to be the small turbo high efficiency piston engines, or the very small gas turbines linked to generators and electric drive.
Worth reiterating that RX-8s registered before 23 March 2006 only command band K road tax due to some ruling or other - it's £225 per year as opposed to £460 I think.
I think, but don't quote me on this, that around this time new RX-8s received improved starter motors and various other good things (mini revision).... so the holy grail therefore is one with these mods, but registered before 23rd March 2006 ! Such a car might not exist - who knows?
I think, but don't quote me on this, that around this time new RX-8s received improved starter motors and various other good things (mini revision).... so the holy grail therefore is one with these mods, but registered before 23rd March 2006 ! Such a car might not exist - who knows?
edwheels said:
Worth reiterating that RX-8s registered before 23 March 2006 only command band K road tax due to some ruling or other - it's £225 per year as opposed to £460 I think.
I think, but don't quote me on this, that around this time new RX-8s received improved starter motors and various other good things (mini revision).... so the holy grail therefore is one with these mods, but registered before 23rd March 2006 ! Such a car might not exist - who knows?
I do. We've got one registered Jan 2006 (although currently for sale *sob*)I think, but don't quote me on this, that around this time new RX-8s received improved starter motors and various other good things (mini revision).... so the holy grail therefore is one with these mods, but registered before 23rd March 2006 ! Such a car might not exist - who knows?
2009 R3's are the ones to go with if you can afford them, if not then 2006 onwards.
Best pre-R3 are those 2006 models in that small window before March 23rd.
Fastdruid said:
I do. We've got one registered Jan 2006 (although currently for sale *sob*)
2009 R3's are the ones to go with if you can afford them, if not then 2006 onwards.
Best pre-R3 are those 2006 models in that small window before March 23rd.
Really like the look of the R3 but compare to my old RX8 I found the R3 seats too narrow on the back. (Maybe Im just a fat git) 2009 R3's are the ones to go with if you can afford them, if not then 2006 onwards.
Best pre-R3 are those 2006 models in that small window before March 23rd.
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