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  #11  
Old 06-27-2012, 07:45 PM
roee roee is offline
 
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Quote:
Originally Posted by Mike S View Post
The Mazda Wankel rotary engine uses an engine driven pump to meter oil directly into the intake system, for the purpose of lubricating the combustion chamber seals.
Yes, understood. It's a deliberate design feature that serves a purpose inside that engine. But it's not the purpose of the engine.

From a user standpoint, high oil consumption, even if by design, is a negative. An undesirable characteristic. And it is fair to point it out as such when comparing the trade-offs between different types of engines.
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  #12  
Old 06-27-2012, 07:48 PM
roee roee is offline
 
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Quote:
Originally Posted by comfortcat View Post
Actually, the correct quote would be: "V-8 engines are notorious for burning gasoline"

Again, not quite. More like "Engine A is notorious for burning more gasoline than engine B to produce the same power".

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Last edited by roee : 06-27-2012 at 07:50 PM. Reason: typo
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  #13  
Old 06-27-2012, 08:09 PM
johnny stick johnny stick is offline
 
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Default Burning oil Huh?

So the RX3 used quite a bit of oil. Then when the RX7 came out, Mazda reduced the oil consumption by, like, an order of magnitude. Then when the Genisis came out, it went down again, this time in order to pass smog. I curious from the RX8 owners out there, how much oil does a Genisis burn? I sure much less than an RX7 and much less than a Lycoming. JMO
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  #14  
Old 06-27-2012, 09:39 PM
Lars Lars is offline
 
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Quote:
Originally Posted by roee View Post
Again, not quite. More like "Engine A is notorious for burning more gasoline than engine B to produce the same power".

You must be an engineer
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  #15  
Old 06-27-2012, 09:43 PM
roee roee is offline
 
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Quote:
Originally Posted by Lars View Post
You must be an engineer
Really, does it show?
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  #16  
Old 06-27-2012, 09:53 PM
Lars Lars is offline
 
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Quote:
Originally Posted by roee View Post
Really, does it show?
As the saying goes, it takes one to know one
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  #17  
Old 06-27-2012, 10:33 PM
Ted Johns Ted Johns is offline
 
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Quote:
From a user standpoint, high oil consumption, even if by design, is a negative. An undesirable characteristic. And it is fair to point it out as such when comparing the trade-offs between different types of engines.
So, are you criticizing the Lycoming or the Rotary with this comment? The typical two rotor uses about a quart every 1500 miles of street driving. This equates to about 30 hours per quart. Most Lycomings would be jealous.
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  #18  
Old 06-27-2012, 11:04 PM
roee roee is offline
 
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Quote:
Originally Posted by Ted Johns View Post
So, are you criticizing the Lycoming or the Rotary with this comment? The typical two rotor uses about a quart every 1500 miles of street driving. This equates to about 30 hours per quart. Most Lycomings would be jealous.
The original comments about high oil consumption of the Mazda rotaries were in comparison to modern automotive piston engines, not Lycomings.

It is also true that the Lycoming we fly also have high oil consumption relative to modern automotive piston engines. And it's fair to point that out as an undesirable characteristic of the Lycomings as well.

Anyway, I wouldn't describe any of this as "criticizing". These are just factual technical trade-offs between different engine designs. Oil consumption isn't the only parameter that matters, but it does weigh in to the trade-off analysis. Mazda rotaries may have many wonderful qualities, and some other qualities that are less wonderful. That their oil consumption is higher than comparable modern piston engines, is a matter of fact.
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  #19  
Old 06-27-2012, 11:10 PM
gerrychuck gerrychuck is offline
 
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I will shed a little tear for the venerable Mazda rotary. I had an RX-3 in the late 70's, which totally kicked the butts of all the Corolla's, etc of the day, then a normally aspirated 86 RX-7 and a tweaked 88 Turbo in recent years. Loved 'em all, despite their thirst for fuel and lack of low-end torque (the turbo, mind you, kicked HARD and spooled fairly low in the rpm band). They were quick, smooth, and revved so beautifully. God help you and your eardrums if you ever had to hear one un-muffled, but the rotary is a unique and endearing piece of automotive engineering that I will truly miss.
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  #20  
Old 06-28-2012, 01:15 AM
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DCat22 DCat22 is offline
 
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Yes, yes, yes.

My only annoyance was with the article about using the word "notorious" for oil consumption, just because its different -- when it's completely expected and by design. (Mazda could have had you add oil to the gas, or used a separate oil tank too...but they went with the most consumer friendly/normal option. But it's still bizarre to consumers I suppose, that they ever have to add oil to a car at all....)

As for the "notorious" and gas mileage though... Yeah, I'm not going to touch that one. Don't get an RX8 for fuel economy.

Quote:
Originally Posted by johnny stick View Post
I curious from the RX8 owners out there, how much oil does a Genisis burn?
I add oil once every month or two... it's not an every fill-up kind of thing. I probably check it and top it off as often as I have with some older "interesting" cars I've owned before.

If you let it get too low you'll get an oil light flicker before anything too terrible happens (in my experience at least... ). I keep a quart in the trunk.

I've been pretty mean to mine. It's treated me well (and it's an early 2004). I know many others that have not been so lucky though...
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