is fuel economy really that bad?
#1
is fuel economy really that bad?
All I read and hear about is how the fuel economy is poor, but in comparison to what cars? I'm currently looking at several cars to buy RX-8, Mitsu Lancer EVO, or Suburu WRX STI. Doing a side by side comparison on fuelecomony.gov they are all about the same, the only other car I can think of to do a comparison to is Honda's S2000 which gets avg. 22mpg(20/25) vs RX-8s 20mpg(18/24). So whats the deal is the EPA numbers for the RX-8 too high or something? I realize the EPA numbers are under ideal conditions. Does the RX-8 get much lower number when driven enthusiastically compared to driving similar style cars like the ones mentioned above? Thanks for your responses.
#3
Extraordinary Engineering
Hwy cruise at 116 km/hr at 22 C = 10 litres per 100 km
Winter driving in traffic I hit 15 litres per 100 km
The '8 gets a bad rap because the engine is tiny but gulps fuel.
Size of a four, power of a six, thirst of an 8
Really the '8 encourages the sort of driving that burns fuel
If you can live with that it'll put a big grin on your face every day!
Winter driving in traffic I hit 15 litres per 100 km
The '8 gets a bad rap because the engine is tiny but gulps fuel.
Size of a four, power of a six, thirst of an 8
Really the '8 encourages the sort of driving that burns fuel
If you can live with that it'll put a big grin on your face every day!
Last edited by DarkBrew; 02-02-2007 at 08:16 PM.
#5
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You can usually figure on getting 1 to 2 mpg below the EPA numbers. That's been my experience with every car I've owned since the numbers began. RX-8 has been no different.
Ken
Ken
#6
Out of NYC
iTrader: (1)
I dont get it. and Im going to say it now.
To whoever complaing about MPG. Sell your 8, or any sports car that you might have
AND GET A PRIUS INSTEAD!!!
Yea YEa, next thing *these* ppl will be like
"Oh Brand X Model X cars get almost the same HP with more TQ can get better MPG blah blahblah"
Stfu alright? I can say the same thing to you.
Thank you
To whoever complaing about MPG. Sell your 8, or any sports car that you might have
AND GET A PRIUS INSTEAD!!!
Yea YEa, next thing *these* ppl will be like
"Oh Brand X Model X cars get almost the same HP with more TQ can get better MPG blah blahblah"
Stfu alright? I can say the same thing to you.
Thank you
Last edited by nycgps; 02-02-2007 at 08:54 PM.
#8
Don't you know I'm loco?
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ugh, yet another "gas mileage?" followed by "you're questioning gas mileage?" thread. Every time someone asks that another person has to leap to YOU IDIOT! BUY A PRIUS (or civic. they usually say civic). frickin' irritating.
To mix it up a little, how about "IDIOT!! HOW DARE YOU QUESTION GAS MILEAGE, PANSY?! BUY A "
Corvette. (28mpg highway)
To mix it up a little, how about "IDIOT!! HOW DARE YOU QUESTION GAS MILEAGE, PANSY?! BUY A "
Corvette. (28mpg highway)
#12
Originally Posted by jasondhsd
All I read and hear about is how the fuel economy is poor, but in comparison to what cars? I'm currently looking at several cars to buy RX-8, Mitsu Lancer EVO, or Suburu WRX STI. Doing a side by side comparison on fuelecomony.gov they are all about the same, the only other car I can think of to do a comparison to is Honda's S2000 which gets avg. 22mpg(20/25) vs RX-8s 20mpg(18/24). So whats the deal is the EPA numbers for the RX-8 too high or something? I realize the EPA numbers are under ideal conditions. Does the RX-8 get much lower number when driven enthusiastically compared to driving similar style cars like the ones mentioned above? Thanks for your responses.
1.3L
#13
Extraordinary Engineering
Originally Posted by jasondhsd
I can live with 17/20, my 95 turbo DSM is getting me at best 14mpg avg. but I drive pretty hard, I just love hearing the turbo spool up lol.
#14
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Originally Posted by 1.3L
There's more to consider than just MPG. It's the cost-of-ownership that counts. Get a quote from your insurance carrier on all of the cars you're considering and then add in your yearly estimated fuel costs for each vehicle. Some high-perf cars will bend you over on insurance costs.
1.3L
1.3L
#16
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Originally Posted by nycgps
AND GET A PRIUS INSTEAD!!!
In electric mode, it's silent. A friend had one for a week long road test. He had a blast driving around shopping center parking lots and watching people jump when they suddenly realized there was a car on top of them.
An actress on a TV talk show told of how she ran her dog over with a Prius-like Lexus, because the dog did not hear the car coming.
Not the same as having an engine that will rev past the speed of light, a car that will stick through any corner made by man, and steering that can only be described as connected directly to the road. But the Prius can have its moments.
As long as they don't make you look at the thing.
Ken
#18
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In a perfect world I would have an eco-friendly electric car for saving the world on a daily drive-to-work basis, and my RX-8 for blasting through the twisties whenever I feel the need.
#19
Extraordinary Engineering
Originally Posted by mikeschaefer
In a perfect world I would have an eco-friendly electric car for saving the world on a daily drive-to-work basis, and my RX-8 for blasting through the twisties whenever I feel the need.
#20
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Originally Posted by mikeschaefer
In a perfect world I would have an eco-friendly electric car for saving the world on a daily drive-to-work basis, and my RX-8 for blasting through the twisties whenever I feel the need.
in a perfect world you wouldn't even have to go outside to go to work...they'd just beam you there...
#21
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Originally Posted by Stavesacre21
what are u talkin about?
in a perfect world you wouldn't even have to go outside to go to work...they'd just beam you there...
in a perfect world you wouldn't even have to go outside to go to work...they'd just beam you there...
#22
A rotary engine will almost always use more fuel than a reciprocating piston engine of the same power output. In a wankel, the thermal efficiency (how much of the energy in gasoline can be converted to work, actual movement) is lower than a piston engine, because of the long, narrow shape of the wankel combustion chamber (formed between the rotor surface and housing), as well as a lower compression ratio than is possible in a piston engine. This thermodynamic inefficiency is partially offset by a wankel engine being lighter than a piston engine of the same power output (less weight to haul around = less gas needed to do it, so a rotary is more efficient when it comes to engine mass needed for a given power output). This lower thermodynamic efficiency is more pronounced at the lower power outputs that a car engine usually operates at (going a steady 60 mph uses only about 10%-20% of an engine's maximum power output, and going 20 mph uses about 2%).
Interestingly, the thermodynamic efficiency of a rotary engine increases with higher power output. Working at 99% of max power output, a rotary would be just as if not more thermodynamically efficient than a piston engine (so our RX8's would get better gas mileage going 150 mph than a Mustang GT would). So, all you have to do is cruise near top speed all the time, and you'll get better gas mileage than a piston engine would!
No car is perfect. No car can have it all, everything is a trade off. The trade off for the RX8's agility, lightness, responsiveness, tossability, handling, and magical connection with the driver is somewhat lower gas mileage. You have to factor in how much the fun and special feeling of the RX8 is worth to you (as well as the price difference between an RX8 and whatever else you are considering, and how far you drive in a year and thus how much you will actually spend on gas). Especially if you buy a used RX8, which is probably a few thousand less than some of the competitors, or if you only drive a few thousand miles a year, you can actually be ahead in out-of-pocket cash flow with the RX8 - overall, it might actualy even be "cheaper" than buying something else! A 2004 RX8 can probably be bought for $10,000 less than a used 2004 G35 or 350Z - that price difference can buy a lot of gas.
More fun and potentially less overall cost! How can you beat that?
Interestingly, the thermodynamic efficiency of a rotary engine increases with higher power output. Working at 99% of max power output, a rotary would be just as if not more thermodynamically efficient than a piston engine (so our RX8's would get better gas mileage going 150 mph than a Mustang GT would). So, all you have to do is cruise near top speed all the time, and you'll get better gas mileage than a piston engine would!
No car is perfect. No car can have it all, everything is a trade off. The trade off for the RX8's agility, lightness, responsiveness, tossability, handling, and magical connection with the driver is somewhat lower gas mileage. You have to factor in how much the fun and special feeling of the RX8 is worth to you (as well as the price difference between an RX8 and whatever else you are considering, and how far you drive in a year and thus how much you will actually spend on gas). Especially if you buy a used RX8, which is probably a few thousand less than some of the competitors, or if you only drive a few thousand miles a year, you can actually be ahead in out-of-pocket cash flow with the RX8 - overall, it might actualy even be "cheaper" than buying something else! A 2004 RX8 can probably be bought for $10,000 less than a used 2004 G35 or 350Z - that price difference can buy a lot of gas.
More fun and potentially less overall cost! How can you beat that?
#23
I get between 18-22 mpg, roughly 70/30 highway/city. I'm satisfied with those numbers.
I have a theory as to why so many are disappointed in the 8's mileage: traditionally, cars with little engines (and the Renesis is little, just over 13" tall) offer superior fuel economy. Maybe not a lot of power or not a lot of torque but, at the very least, good mileage. So to many, the Renesis is a "disconnect"—a little engine without great fuel economy just doesn't make sense. The fact that the 8 doesn't have gobs of torque adds to this sense of a disconnect—"hey I might be willing to give up power in exchange for superior fuel economy, but no torque AND mediocre mileage?!? That's not right!"
Needless to say, with a little engine that's VERY different from all the other little engines in the world, the traditional "small engine/superior mileage" trade-off doesn't apply here. While most little engines offer superior mileage, the Renesis offers up something entirely different: unmatched smoothness, of course, but also superior feel and handling, courtesy of the near mid-engine placement of the tiny Renesis. Things like "smoothness," "feel" and "handling" are secondary qualities that, frankly, most Americans don't understand or care about.
I have a theory as to why so many are disappointed in the 8's mileage: traditionally, cars with little engines (and the Renesis is little, just over 13" tall) offer superior fuel economy. Maybe not a lot of power or not a lot of torque but, at the very least, good mileage. So to many, the Renesis is a "disconnect"—a little engine without great fuel economy just doesn't make sense. The fact that the 8 doesn't have gobs of torque adds to this sense of a disconnect—"hey I might be willing to give up power in exchange for superior fuel economy, but no torque AND mediocre mileage?!? That's not right!"
Needless to say, with a little engine that's VERY different from all the other little engines in the world, the traditional "small engine/superior mileage" trade-off doesn't apply here. While most little engines offer superior mileage, the Renesis offers up something entirely different: unmatched smoothness, of course, but also superior feel and handling, courtesy of the near mid-engine placement of the tiny Renesis. Things like "smoothness," "feel" and "handling" are secondary qualities that, frankly, most Americans don't understand or care about.
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Rotary MPG in a Miata?
Hey guys! I own a 2006 Mazda Miata! (The new body style) and we at the miata forums have noticed alot of similarities between the RX-8 and our MX-5's. For one thing, we can use to same sway bars from the RX-8 (its actually a popular upgrade). Also someone in Germany has successfully pulled off a Renesis Swap into our car.
My question is basically, being that the Mazda Miata's stock weight is somewhere between 2,400 and 2,500, we are so far about 500 pounds lighter than you guys. Would the swap of your engine into our car increase its MPG noticably?
The fact that our cars come with an Inline 4 is another advantage. If we take out our heavier conventional engine and put in the rotary, not only would we make more power than the stock engine, but lighter. so that 500 pound difference could turn into 700! Thus improving acceleration, cornering, and once again, possible MPG.
My question is basically, being that the Mazda Miata's stock weight is somewhere between 2,400 and 2,500, we are so far about 500 pounds lighter than you guys. Would the swap of your engine into our car increase its MPG noticably?
The fact that our cars come with an Inline 4 is another advantage. If we take out our heavier conventional engine and put in the rotary, not only would we make more power than the stock engine, but lighter. so that 500 pound difference could turn into 700! Thus improving acceleration, cornering, and once again, possible MPG.