In addition to a heavy-duty starter, start-stop systems require such components as enhanced engine control, battery management, DC/DC converters, and more robust crankshaft sensors.
(Source: Robert Bosch LLC)
Federal-Mogul has released a new line of engine bearings that function well under frequent stop-start cycles. It is called Irox and comes in versions for both diesel and gas engines. I see it is used in the new (2014) Corvette v8 engine, and most likely is being used more widely. Other technologies exist for cylinder walls, valve guides, piston rings, etc., which allow long engine durability under start-stop conditions.
Providing oil pressure to assure adequate lubrication is in place at startup would indeed require additional hardware, but the devices that would do the job are old technology, fully mature and already used for other applications for many years. Besides that, most of the time the restart would be soon enough that the oil would not have much time to drain away.
For the very largest improvements there will need to be driver control rather than computer control, and those savings will be more in the 40% to 60% range, at least for city-type driving. But only at the hands of the more skilled and attentive drivers. On the other side, running the air conditioner would not only kill the mileage improvement, it would also probably increase the needed battery size by a factor of at least ten.
A study was done years ago that said about 80% of engine wear happens in the first few seconds after starting because of lack of oil pressure. What is being done about this? Haven't heard. Maybe yet another motor running the oil pump?
I keep cars for years & now they are getting even more complex, I don't want disposable cars like all other current day appliances.
I will never buy a S/S car. The percentage of fuel savings doesn't come close to what the cost of fixing it, or the wear it will see.
Just give me that 50 mpg diesel power as in Europe.
Any hybrid that can't keep the engine and therefore A/C running at a light won't sell in the southwest. Prius (and I assume Honda) keep the engine running so the A/C works. My Prius starts up on battery, the shift to engine is imperceptable and reliable. If the start-stop is properly integrated into the engine and controls, it should be reliable. And on the subject of an all battery electric, it is totally illogical and a waste of ink (or bandwidth) to discuss.
I can understand why you might want the reliable, easy to fix catalytic converter free gas guzzler. But you don't get to choose because that car drives up gas prices and pollutes the air for all of us. I am old enough to remember LA summers in the years before emission controls. On some days you could hardly breathe. And if you think $4 a gallon is bad, try $6. Or $20.
An equally serious problem is that prior to the "54.5 mpg by 2025" agreement, our 35MPG standard put us at risk of losing all auto sales to China, whose standards will be 42.2 MPG (18km/L) as iof 2014. It's the same for low emissions in Europe. Meet the rules or don't sell. 50 years ago US automakers could do whatever they wanted. No more. If we can't sell internationaly our automakers will fail. Depending on who you believe, the US auto industry is responsible for 5-14 million jobs, or 4-10% of total US employment. You think unemployment is bad now? Try it at 15% and watch the pundits fly.
Emissions controls, hybrids, start-stop, and plug-in electrics are all here to stay. But they don't need to be half-baked like your friend's truck, that was using the starter motor in ways it was not designed to be used. Soon they will get it right: someting like a brushless motor with the magnets built into flywheel. No brushes, no solenoids or mechanics to fail. Either way, like it or not, it's coming.
When my gun safe was delivered (yes, I am clinging, bitterly, as BHO quipped), the truck driver was complaining that his company, a large national firm, had installed Stop-Start technology on all their diesel trucks, and that they were suffering a high frequency of starter failures as a result. His disdain for the "improvement" was palpable. This is real world feedback.
I'm glad some of you choose to reap the benefits of this technology, more power to you, but I will gladly pay for the extra fuel needed to keep my engine idling at red light, etc. The extra complexity and cost that all these lovely and oh-so-helpful systems inherently bring to the table, from ABS brakes to tire pressure monitoring to air bags to catalytic converters, is always minimized, until it is time for repairs, as someone mentioned. And usually out of warranty. Can we please let the market decide whom wants this stuff, and let others buy the more basic alternative? That would be a true example of "diversity" and "tolerance" that I could get behind.
I love technology....so this isn't a condemnation by any means.
Listen to the discussions. I have a great idea (in my simple mind). I think you should buy it. So I market/lobby my idea to safety and regulatory bodies. Basically I am legislating myself a profit.
Lots of good automotive ideas: nitrogen filled tires, E85+, start/stop systems, drowsiness detection, back up cameras, lane change warning systems, on-board navigation systems, anti-lock brakes, autonomous vehicles, intelligent headlights....on and on.
Each is technologically wonderful.
At what point have we made autos prohibitively expensive to purchase and maintain after the warranty has expired?
This is nothing but marketing hyperbole, and Engineer's shouldn't help such attempts to confuse the market place. This is nothing but a beefier starter circuit, a circuit that exists already in non-hybrid vehicles. Better to call it "Golf Cart" starting (yes, it's the same as gas powered golf carts which start the engine when you press the accelerator).
It's certainly easier to implement in true hybrids, since while the engine is starting, your initial propulsion is by electric (hiding what's really going on from the driver).
As far as shutting the engine down while coasting, most modern computer controlled engines already do this, the trick is knowing how to implement it. Basically, you want to press down on the throttle just enough to keep the car from using the engine drag to slow down, but not enough for the computer to give it any gas. You don't want to shift into neutral, because the engine needs gas to idle. I did this with a friends gas guzzler on a long trip and was able to get 20% better mileage than the best they could do.
BTW - Europeans have been living this technology manually for decades. Traffic lights there go "yellow-red" just prior to turning green. It gives everyone a chance to start their engines and be ready to go (eliminating the need to predict when to start your engines).
Californiaís plan to mandate an electric vehicle market isnít the first such undertaking and certainly wonít be the last. But as the Golden State ratchets up for its next big step toward zero-emission vehicle status in 2018, it might be wise to consider a bit of history.