RX-8 Hydrogen RE a Dual Fuel Car 369
greekgod8591 writes "Japan's Mazda Motor Corp. said on Wednesday it will begin leasing a dual-fuel car that can run on both hydrogen and gasoline in the auto industry's latest effort to reduce oil consumption in vehicles. Mazda said the RX-8 Hydrogen RE, based on its popular RX-8 sports car, gets around these problems by running on gasoline in the absence of a hydrogen fuelling station, and using existing engine parts and production facilities to lower costs."
Currently worthless in North America (Score:5, Insightful)
And so, this is Mazda's PR machine cooking up hope where it'll be a decade or more before consumers will see something tangible on this side of the Pacific. Must be a dull news day.
Re:Only $3577 per month (Score:4, Insightful)
Re:Naysayers (Score:3, Insightful)
I suppose it is all about how a person looks at things. If their primary goal it to make a zero emission car, they are totally focused on hydrogen. If the goal is to stop pumping money to unstable parts of the world or to simply improve energy independence, then methanol and ethanol is an obvious option.
Questions (Score:2, Insightful)
Do they realize that electricity (a.k.a. Fossil Fuels) must still be used to break apart the water?
Do they further realize that any compressed gas is a pain to transfer anywhere?
When will people realize that ethanol, until it can be produced in extremely massive quantities (30 gallons per vehicle per week, minimum ), is merely a short-term solution to a long-term problem?
Why are people nowdays programmed to think just like the media wants them to think?
-Chubbz
Re:That's a tankage issue (Score:2, Insightful)
Re:Questions (Score:5, Insightful)
Re:Currently worthless in North America (Score:3, Insightful)
Put the solar cells on the roof, and feed the power back into the grid, lowering your electric bills and your grid power consumption. Then buy a normal car. The grid will burn less coal, balancing out your auto emissions.
Lots of Misinformation here on Slashdot. (Score:5, Insightful)
The rotary has some big benefits and some notable acheivements:
Power-to-weight ratio is excellent. Minimal moving parts, no valve train and short eccentric shafts mean that vibration is very low, and this enables rotaries to rev very smoothly and at relatively high RPM (10,000+ RPM on a normally aspirated rotary in street trim is not difficult). Hot, high velocity exhausts make turbocharged rotaries capable of very high power levels.
The Mazda rotary has seen enormous success on the racetrack - Mazda is the only japanese manufacturer to win Le Mans, and the RX-7 has been extremely successful - winning more races outright than any other model in major US racing classes.
A 1.3L rotary engine is easily capable of producing 500bhp with a good turbocharger and fuelling setup, and the most powerful 13Bs used in drag racers produce up to 1000bhp in the extreme (it is true that a 1000bhp 13B will not last long).
the 2 litre (20B) engine was the torquiest production engine in a japanese car while the JC Cosmo was being made, and the boosted 20B in the worlds fastest rotary does the quarter mile in 6.9 seconds/202 mph with something approaching 1000 bhp.
The engine that powered the Le-Mans winning 787B in 1991 used a 2.6l 4-rotor normally aspirated engine with ceramic coatings, which produced about 700bhp, exhibited an almost perfectly flat power delivery curve over the entire race, and when disassembled at the end of the 24 hour race, showed practically no wear whatsoever.
Not only does the rotary produce excellent power for it's weight and displacement, it is also very reliable on a racetrack, or as an airplane engine.
On the downside:
Unfortunately heat/cooling cycles are the rotary's worst enemy, as the engine is constructed of a 'sandwich' of different metals, which tend to expand and contract at different rates. This leads to failure of coolant seals (letting water leak into the engine) - analogous to head gasket failure.
Apex seal breakage is the other major failure mode of the rotary, often due to detonation, or oil starvation.
Both of the major failure modes necessitate removal and rebuild of the engine block, which is labour-intensive and expensive.
Fuel efficiency is very difficult to maintain over a wide rev-range because of the shape of the rotary's combustion chamber, which is long and narrow, meaning it is difficult to get a smooth flame front and complete combustion, something piston engines (due to their 'closer to spherical' combustion chambers) have a natural advantage in.
Ceramic coatings and side-port designs such as used in the Renesis keep heat in the charge and insulate engine parts better, which provides cleaner burns and smoother combustion.
The Renesis (1.3l 2-rotor RX-8 engine) can burn hydrogen because it's side-ported intakes and exhausts (as opposed to the peripheral exhaust ports in production cars and the peripheral intake + exhaust in race engines) enable a complete separation between the intake, combustion and exhaust chambers, equivalent to zero valve overlap in a piston engine, while retaining the ability to rev high and without majorly impacting on flow.
This is more or less impossible with a conventional 2 or 4-stroke piston engine - any piston engine running hydrogen either needs a totally different and switchable cam profile which produces anemic performance, or is built to run on dedicated hydrogen fuel and is still a pretty poor performer.
The Renesis is an outright better hydrogen hybrid engine than anything anybody at any other car manufacturer can come up with, despite their much longer histories and enormous research budgets.
You can only go 62 miles on a tank of hydrogen in an RX-8, but how far can you go running hydrogen in any other vehicle? Not very.
Many people trash the rotary out of ignorance, but the truth is that it is the
Re:Currently worthless in North America (Score:3, Insightful)
If rich families really want to make an impact on the environment and show everyone they care, a better solution would be to trade in their mammoth SUVs and drive a compact car. There's no need for the fancy hybrid or hydrogen vehicle. Current cars using common technology (NOT hybrids but just regular gasoline engines) already get around 40MPG.
I guess the auto companies are smart how they market their vehicles. The only way to get flashy rich people back into normally sized cars is to offer some hot technology that they can show off.
Re:What about the sealing problems? (Score:2, Insightful)
Baka... the rotary engine's problems were licked in the 1979 Rx-7. That includes apex seals, and side seals / scrapers.
Mazda NEVER dropped the rotary. They started selling the Cosmo 110 in 1967, and continously offered a rotary can in the US from 1970 until 1995, at which time the FD Rx-7 was pulled out of the US market -- but they still sold in Europe and Japan and Australia until 2002, when the production line stopped making Rx-7 to gear up for the upcoming Rx-8. So mazda never DROPPED the rotary engine.
The turbo cars had issues, mainly because of the sheer volumes of heat the rotary puts out. The last-generation Rx-7 (the FD) damn near killed mazda because of warranty claims.
HOWEVER... the atmospheric 12A and 13B, since 1979, have been extremely reliable engines. Just don't let them overheat.
The only 'problem' left to conquer is the pathetic mileage. This is mainly due to thermal efficiency (or rather, lack thereof.) In time, I'm sure mazda will lick that one as well.
Re:Lots of Misinformation here on Slashdot. (Score:2, Insightful)
The Mazda 1991 Le Mans victory was an outright win, over all classes.
The ones you mentioned are merely class wins.
Want a spectacular outright win? 1947, Ferrari, with a very tiny 1.8 liter v-12... that little barchetta trumped all the bigger cars in higher classes to win the race outright.