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  #1  
Old 11-09-2000, 10:47 AM
Duck Hook Duck Hook is offline
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A golf cart engine comes on and goes off by merely pressing and releasing the accelerator. I'm sure this is not alien technology or anything, but just how does it work?

Wouldn't it make sense to use this system on small econo-box automobiles in city traffic? I can see it how it would be problematic during times of extreme weather requiring an "always on" setting for A/C or heat. At a glance, it seems like an easy way to cut down on fuel consumption and emissions.
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  #2  
Old 11-09-2000, 11:19 AM
Jingo Jingo is offline
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Quote:
I'm sure this is not alien technology or anything, but just how does it work?
Don’t be so sure…have you seen the kids they have working at the caddyshacks these days?

It just has an electric starter that’s engaged as soon as you step on the pedal. Releasing the pedal cuts off the fuel supply (rather than reverting to an “idle” setting like in a car). No big deal.

Quote:
At a glance, it seems like an easy way to cut down on fuel consumption and emissions.
Golf carts aren’t designed to do either. They’re actually horribly inefficient engines. But, of course, they don’t run when you’re not in ‘em, and (thus) they’re quiet. Those are the major requirements…not fuel efficiency.

Perhaps an actual engineer can put this a better way, but IIRC: Starting and stopping an engine requires much more fuel than leaving it at idle for a short period of time, and there’s a lot of poor combustion (i.e. pollution) in the few seconds when the engine is starting or stopping.

Thank you, and Goodnight.
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  #3  
Old 11-09-2000, 11:31 AM
Enos Strate Enos Strate is offline
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I think I read somewhere that the Honda Insight does just that- it cuts off when you come to a complete stop. I'll try to find a cite. I know that the new Toyota Prius claims to get better mileage in the city than it does on the the highway (52/45). It probably does something similar and uses regenerative (sp?) braking to recharge the battery when you are in stop and go traffic. Anyone have more information on this?
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  #4  
Old 11-09-2000, 11:42 AM
Enos Strate Enos Strate is offline
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sorry for the double post: Here is the info on the Insight taken from Honda's website at http://www.honda2001.com/models/insight/faqs.html
Quote:
Q: What is the IMA[Integrated Motor Assist] system's idle-stop feature?
A: When the vehicle stops, the IMA system's idle-stop feature temporarily shuts off the gasoline engine to save fuel and minimize emissions. The system is automatically engaged when the driver shifts to neutral and takes his foot off of the clutch. As soon as the driver puts the car in gear again, the IMA motor engages the transmission and restarts the gasoline engine.
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  #5  
Old 11-09-2000, 11:55 AM
justwannano justwannano is offline
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It has been a while since I've run one but they had centrifical clutches. It would not be possible to run a gasoline engine on the highway with one. The engine would have to run at to high a speed. The automobile transmission keeps the engine speed down and the high gear ratio is what produces the speed.
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  #6  
Old 11-09-2000, 12:02 PM
Duck Hook Duck Hook is offline
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Golf carts aren’t designed to do either. They’re actually horribly inefficient engines. But, of course, they don’t run when you’re not in ‘em, and (thus) they’re quiet. Those are the major requirements…not fuel efficiency.
I didn't mean to suggest duplicating a golf cart engine in a car but more using the idea on an efficient engine. If starting the engine consumes more fuel and generates more pollution than letting it idle for short periods, then it wouldn't be beneficial.

BTW, how does the electric starter disengage once the engine is running? In a car, you have to do that manually.
Maybe it IS alien technology!
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  #7  
Old 11-09-2000, 12:16 PM
Duck Hook Duck Hook is offline
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OOO! Thanks for the reference ES. I'm always a day late with my brilliant ideas.

justwannano: Some Subaru Justy's came with an ECVT (Electronically Controlled Variable Transmission) which acts like a centrifugal clutch except it varies the gear ratio at higher speeds in order to decrease engine rpm...more magic I can't comprehend without detailed diagrams.
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  #8  
Old 11-09-2000, 12:47 PM
sailor sailor is offline
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>> It has been a while since I've run one but they had centrifical clutches. It would not be possible to run a gasoline engine on the highway with one

You have obviously never driven a Citroen 2CV
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  #9  
Old 11-09-2000, 12:50 PM
Una Persson Una Persson is offline
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Starting and stopping a warmed-up engine does not have to consume a significant amount of fuel, or produce a significant amount of pollution. Whether or not starting and stopping a warm engine uses more fuel or creates more pollution than allowing it to idle for a certain time depends on a great many variables. This is not an easy question to answer in a general sense; only in specific cases or for specific cars can it be answered.
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  #10  
Old 11-09-2000, 12:51 PM
justwannano justwannano is offline
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Duck Hook
I believe it becomes a generator once the engine is started.
Sailor Yup your right.
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  #11  
Old 11-09-2000, 02:17 PM
Telemark Telemark is offline
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The new Saturn SUV will offer a CVT with the 4-banger.
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  #12  
Old 11-09-2000, 09:28 PM
Balthisar Balthisar is offline
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I can't cite it this second, but I think that a Volkswagen predates the Japanese cars' idle-stop feature. I believe it was a European-only model of some econobox.

As far as re-starting engines, it does not cost more fuel or cause more emissions than leaving the engine running, with the provision that the engine and cataclytic converter are fully warmed up. 'Course, I'm assuming you're speaking about a modern vehicle with direct fuel injection and an engine control computer.
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  #13  
Old 11-10-2000, 04:45 AM
Spiny Norman Spiny Norman is offline
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FWIW, the ultra-economic VW Lupo 3L has this feature.
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  #14  
Old 11-10-2000, 08:54 AM
Jingo Jingo is offline
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Balthizar said:
Quote:
'Course, I'm assuming you're speaking about a modern vehicle with direct fuel injection and an engine control computer.
You and Anthracite are correct on the point that it MAY not take extra fuel or produce extra emissions to stop/restart an engine. The caveat is that the engine must be warm and modern. Modern computer-controlled engines can do astounding things if they’re designed to do them.

The idea of an engine which cuts off instead of idling, despite the recent prototypes, seems less efficient than simply designing a high-efficiency, low-emission, super-computer controlled engine (or hybrid gas-electric, electric, hybrid fuel-cell, solar or whatever). Of course, I could be wrong.

Thank you, and goodnight.
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  #15  
Old 11-10-2000, 08:58 AM
handy handy is offline
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Duck, golf carts are already legal in many cities for driving on the streets, including mine.
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  #16  
Old 11-10-2000, 11:48 AM
Duck Hook Duck Hook is offline
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handy, do you have to register and license the cart?

I imagine an uneasy silence at stop lights when eveyone's engines shut off.

I'm hijacking my own thread...

Do "big" city taxi services still use those GM/Ford boats with V8 gas guzzlers? Sure, an airport run might require more passenger and trunk space, but I would think most fares would be one or two passengers with minimal baggage. (BTW, I live in KC. We don't have a terribly active "downtown" and the city is so spread out, most people drive. I don't consider KC to be typical of other "big" cities.)

In the past, V8 engines were superior as far as longevity and handling the wear and tear inherent with city driving. Hasn't the technology made small 6's and 4-bangers a good alternative?
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  #17  
Old 11-10-2000, 04:41 PM
casdave casdave is offline
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Many small mtorcycles such as the Honda 50 family run with centrifugal clutches but you would notice them running on tickover.

Even the new generation of 4 stroke twist'n'go scooters have noticeable engine noise.

I am not familier with fuel cell techmoogies but maybe these could operate silently and efficiently.

The greatest energy consumption in almost any car is not the fuel used to propel it but rather the energy used to make it.

So when they keep telling you it's very green to buy a new energy efficient car you can always throw that back.
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  #18  
Old 11-10-2000, 05:57 PM
handy handy is offline
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"handy, do you have to register and license the cart?"


Yeah, it has to have a plate on it too. Only one store has one. It's an electric model & they park it in front when they charge it. I can only imagine their electric statement.
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  #19  
Old 11-11-2000, 02:15 AM
Balthisar Balthisar is offline
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Quote:
Originally posted by Duck Hook
Do "big" city taxi services still use those GM/Ford boats with V8 gas guzzlers? Sure, an airport run might require more passenger and trunk space, but I would think most fares would be one or two passengers with minimal baggage.
In most of the parts of Mexico I've been to, the cabs are tiny, miniscule little things, mostly Nissan Tsubu or Tsuro or something (well, tiny little Nissans, like the 323 was). Heck, in the Mexico City area, there are a fair number of late-model VW Beetles as cabs -- I don't mean the "new Beetle"; I mean the classic. So you're right, big engines aren't necessary in most cases.

Here in the Detroit area, there aren't a whole lot of cabs. Most of them are older than 6 or 7 years, and not in great condition, although there is a yellowish cab company with a new, nice-looking fleet. The so-called "airport taxis" are actually superior, and cost the same (+/-$10), and you get a brand new Lincoln, a uniformed driver, and a mostly unmarked car. But with a BIG engine.

FYI - most of the taxis I've used in Germany were fairly nice Mercedes, with a mediocre BMW thrown in for variety. The rates were still cheaper than U.S., too. And gas was (still is) EXPENSIVE there!

Quote:
In the past, V8 engines were superior as far as longevity and handling the wear and tear inherent with city driving. Hasn't the technology made small 6's and 4-bangers a good alternative?
The 3.8L 3800 series engine from GM is well-regarded as one of the finest, longest lasting in the industry among ALL engines of ALL nationalities. They typically outlast the rest of the car. I know quite a few people that are over 200,000 miles on their 3800's.

Four bangers you shouldn't trust, unless they're Japanese (err, I mean from a company that's typically regarded as "Japanese"). Trust me, we just can't build them yet. FYI - many American-brand cars use foreign or foreign-engineered small engines, so this isn't a slam against the American auto industry -- just know you're buying!
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