AutoblogGreen

Good point Mike Z, this Mike Allen's idea is not a new one, it was tried with the Insight flop, I certainly hope no one at GM takes this naive article as anything more then what it is; a myopic, ill informed opinion from some 60s burnout.

First, the savings using hippie bus would be totally offset by the sales killing fatal flaw that would be a lack of acceleration, ability to climb hills, merge on freeways etc. Earth to hippies---EV is not a widely accepted as mainstream, you put a wimpy engine in the Volt and people will judge the entire tech as suspect, we can't afford that if we want to ween off oil.

Those of you who can afford extra cars are welcome to take a flier on a car with limited abilities, but the rest of us in the real world want a "car" to drive, not a golf cart like A.Brien with his 20 h.p. car.

As for meme, the % of drivers needing to hit 100mph? That's the wrong question, the real one is how many of their ICE competitors do? This "need" question is kind of Orwellian. More importantly its these impractical green-extremist ideals that too many want to impose on this car that would kill its sales.

Ever hear of "range anxiety?" A lot of green idealists thought that was a small price to pay for the EV1's awesomeness, then the auto manufacturers did some market research and realized that almost no one would ever sacrifice the ability to drive more then 80 miles before a 6 hour recharge. Its all well and good to post on a blog saying what people should sell or what people need, but consumers are forking over big $ investing in something, not throwing around an opinion on what would be nice. E-REVs needs normal horse power.

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This articles basically says the same thing i said, Imagine if we all only produced more co2 when we ran out of juice or every 1 or so . We woudl not be in this global warming mess

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A 600 cc motorcycle engine might be able to produce 100 hp, it may have to run at 14,000 rpm to do so.

Motorcycle engines do not have to meet the same emissions standards as cars do, they are about 3 times dirtier. They also are not designed to last as long, the emissions components in a car may have to last for 100,000 miles, motorcycles are not expected to last this long.

A larger engine can produce more torque which means that it can run at a lower rpm and still produce the same hp. Lower RPM means less high frequency noise, and less wear on the generator.

Yes they could use a smaller engine, and there are very good reasons for not doing so.

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Looks like meme had the right analysis - the engine was sized to be able to maintain a high rate of speed, at least until the fuel ran out or the driver needed a break.

One erroneous assumption that keeps popping up is the notion that the engine is just there to "recharge the batteries". No, that's what the wall outlet is for. The IC engine in the E-Flex series hybrid complements the battery when the state of charge drops below a certain point. Most of the electric energy goes directly from the generator to the drive motor, bypassing the batteries. When the range extender is running, charging is done only if there is excess power available, and power is drawn from the batteries only if extra power is needed for brief bursts of acceleration.

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@rj
Re motorcycle engines, I would be quite interested in the facts to support your 3 times dirtier, I was under the impression that they used similar technology to cars. viz. fuel injection with oxygen sensors and soon they will ALL be incorporating drive by wire and 32bit microchip capability. What would be making them less clean ? And for that matter why would they last less longer than automobile engines ? Perhaps you could divulge some details and enlighten us with your privileged knowledge.

My understanding is that the high rpms would be necessary only for the 0 to sixty stoplight Grand Prix which would conclude in around eight seconds covering just 117 yards at which point the engine would be allowed to spin down to less stratospheric rpms. During cruise conditions the engine would be made to work at a higher torque but with lower rpms to minimise frictional losses. This is something engines coupled to conventional transmissions cannot do even in overdrive. These larger engines are forced to run somewhat faster but with a lighter loading for pedal response. A hybrid engine, in contrast, is decoupled from the wheels so it can accelerate quickly from that much lower rpm, spinning up to a high power capability without the inertial mass of the car crippling it as in the case of conventional automobile transmissions.

As regards objectional high frequency engine noise this is about acoustic damping not thermodynamics. I can tell you, from personal experience, that Lexus has that licked for their 3.0L engines so a 600cc should be no trouble to competent engineers.

Generator wear, assuming brushless AC machines, would be nonexistent. Remember that a generator for 100Hp at 12000rpm is a mighty small machine, that's why they have been extensively used by avation for many years to generate 400Hz current. It's one of the advantages of having the luxury to rotate at those high speeds that you end up with lighter and smaller machines. Smaller means less expensive too, which is key for rotors that contain samarium cobalt magnets. In general electrical machines are sized by torque NOT power. So you want high rpm low torque for those mobile applications where low mass is also important. Some motorcycles and the ubiquitous french automobile, the CV2 mount the generator rotor externally on the end of the crankshaft on the other side of the engine crankshaft bearing. Furthermore since overhang is minimal for thin rotors the outboard generator bearing can be omitted. You end up with a generator that is totally absent of the usual support bearings, since the engine crankshaft bearing would have to be there regardless anyway.

Before the naysayers respond about doing that at the 100Hp level perhaps I need to point out that a motorcycle, or automobile generator for that matter, is sized for full power at 800rpm. At 12,000pm it should be capable of fifteen times its nominal 500W or 7.5kw. Extrapolating further a real life 75Kw would need only to be about 2.2 times longer than that and in diameter some 2.2 times greater as an idea for a ballpark estimation. Regarding rpms, I should point out that MG1 in the 2nd Gen Prius is rated for 10,000rpm while the one in the Camry Hybrid is rated for 14,000rpm. Not only that but their shafts are hollow since in this system the engine crankshaft doesn't drive them directly but is extended right through them to the other side of a planeterary gear where it picks up the planet carrier. Now that is a system to say "Holy Cow" about. Obviously the news hasn't reached 260,000 who this year will purchase a vehicle using that system.
"Yes they could use a smaller engine, and there are very good reasons for not doing so." Sorry but that's just BS to me. You've got to do better. A lot better.
T2

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1.0-1.3 gas engines,optimized through technologies such as direct injection,and continuously variable valve timing and dwell, utilized in lighter weight vehicles can result in 40-50 mpg cars that are not hybrids and therefore do not require large toxic battery packs or dealer service and can be run on cellulosic ethanol.Another advantage:people could afford them.

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