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SKYACTIV-X: first commercial gasoline engine to use compression ignition

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Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#171

Post by userbinator »

I consider the headline slightly misleading, since compression ignition engines that run on a variety of fuels, including gasoline, were relatively popular around the turn of the century:

https://en.wikipedia.org/wiki/Hot-bulb_engine#Advantages

Another big attraction with the hot-bulb engine was its ability to run on a wide range of fuels. Even poorly combustible fuels could be used, since a combination of vaporiser- and compression ignition meant that such fuels could be made to burn. The usual fuel was fuel oil, similar to modern-day diesel fuel, but natural gas, kerosene, crude oil, vegetable oil or creosote could also be used.

Also known as "semidiesels".

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#172

Post by philipkglass »

coredog64 wrote: post #161
jonsen wrote: post #94

Earlier quoted context omitted.

Someday someone might invent an efficient process for making gasoline from renewable energi sources.

LANL published a paper circa 2007 or 2008 on how to make carbon-neutral hdyrocarbon fuel using carbon in the air and the electricity and waste heat from a nuclear plant. According to the paper, it was competitive with oil-based gasoline at around $5/gallon.

You're referring to the Green Freedom concept:

http://bioage.typepad.com/greencarcongress/docs/greenfreedom...

Its authors badly underestimated how much new American nuclear reactors would cost.

We performed economic analyses on a partially optimized baseline concept based on a single Gen III PWR to provide power for the process. The analyses estimated a capital cost of $5.0 billion for an 18,400 bbl/day synthetic-gasoline plant and $4.6 billion for a 5,000 tonne/day methanol plant. Nuclear power accounts for more than 50% of the total plant capital investment.

If just over 50% of that cost is supposed to be nuclear plant, it would be $2.5 billion for a Gen III pressurized water reactor. ($2.9 billion now, accounting for a decade of inflation.) The just-abandoned VC Summer project was supposed to build two new Gen III PWRs in South Carolina. They pulled the plug because estimated cost of completion had spiraled up to $25 billion ($12.5 billion per reactor).

https://neutronbytes.com/2017/07/31/utilities-pull-the-plug-...

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#173

Post by ajnin »

TomMarius wrote: post #58
robin_reala wrote: post #49

Earlier quoted context omitted.

Outside of Europe maybe. Inside, well, UK and France have already said no more ICE vehicles to be sold past 2040, and other countries are planning the similar (including India). That’s a big loss of market and consequent economy of scale.

Politicians have said things, but no laws have been passed yet - and these laws can be (and have been in the past) changed.

In the immortal words of former French president Jacques Chirac :

"Promises only bind those who believe them."

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#174

Post by coherentpony »

aidenn0 wrote: post #157
thenewwazoo wrote: post #155

Earlier quoted context omitted.

For what it's worth, I went from a WRX to a 2L 3i and don't miss the extra horsepower because we felt, frankly, that they're all slow, so why pay a premium for slightly less slow? With that said, it's plenty fast enough for city driving and is the most fun FWD drive car I've driven, bar none. Hell, it's the best car I've owned and only barely not the most fun (after my RX-7). The interior is great, it's cheap to run,…

There are some dangerously short freeway on-ramps where I live, so "slightly-less-slow" can mean a few extra feet between me and a tractor-trailer.

Austin?

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#175

Post by aunty_helen »

fnj wrote: post #104
kbenson wrote: post #86

Earlier quoted context omitted.

> Pure EV purists dislike PHEVs because they have the complexity of an ICE car + an EV car, but I think there's some serious advantages. I would imagine most the complaints are for when the ICE actually powers a drivetrain. If it's essentially a generator to keep the batteries from depleting too far, that's not much extra complexity it all. Have a problem with the generator? Just swap it out with a new or rebuilt one…

> a Tesla uses about 300 Watts a mile @ 55 Mph This is nonsense. The dimensions are wrong. Watts are instantaneous power. To be meaningful, you would have to give either kWh/h or kWh per mile or km. Besides that 300 W is only 0.4 hp. Sorry, but that is just not credible.

Not to dispute your claim that it's low, but the physics checks out. The cited link saves me explaining it: >Reports are 300 W/mile at 55 mph. If you do the product of these two numbers (300 * 55) all units but W will cancell eachother out so the answer is 16500 W = 16.5kW

The time component being on the mph allows the conversion.

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#176

Post by connorcpu »

oh_sigh wrote: post #146
ouid wrote: post #140

Earlier quoted context omitted.

I visited a Tesla store once in mountain view, and they have a great little demo where you can check the cost of charging your car in various states. Washington DC, for whatever reason, gets its electricity from a gasoline power plant. In Washington, the Model S gets 28 MPG. This happened a while ago so I could be misremembering, but regardless I don't believe that the environmental value of electric vehicles has bee…

That is wrong. Almost all of the energy DC uses comes from its interconnect to the RFC grid. Locally, it does look like 2/3rd of the power DC generates is nat gas, and 1/3rd gas or gas-like, but it doesn't make sense in a grid structure to assume that the energy produced near you is the energy you use. https://www.eia.gov/state/?sid=DC#tabs-1

Given that its neighbors' top two electricity sources seem to be Nat Gas and Nuclear, seems probable that most of the electricity comes from those sources

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#177

Post by outworlder »

ouid wrote: post #140
oatmealsnap wrote: post #35

Earlier quoted context omitted.

Gasoline engines aren't going away for a while; even when every self-driving car is electric, there will be a market for people who want gasoline engines. If it gives a bump in fuel economy to the next (last?) generation of gasoline and hybrid vehicles, great! I also wonder if the maintainability of these engines will be the same as with diesel. That would be another big benefit.

I visited a Tesla store once in mountain view, and they have a great little demo where you can check the cost of charging your car in various states. Washington DC, for whatever reason, gets its electricity from a gasoline power plant. In Washington, the Model S gets 28 MPG. This happened a while ago so I could be misremembering, but regardless I don't believe that the environmental value of electric vehicles has bee…

> This happened a while ago so I could be misremembering, but regardless I don't believe that the environmental value of electric vehicles has been realized

Indeed.

However, look at it this way: which is easier to replace, the entire fleet, or centralized power plants?

Every time a new windmill or solar panel is added, your Tesla gets that much cleaner. And that's something you can do yourself if you want to. Electricity is fungible and your car could not care less where it came from.

Oil changes have a non-negligible impact for the environment as well. And then there are all those components that have to be replaced from time to time and end up in landfills (spark plugs/cables, timing belts, etc).

So I believe electric cars today are already a net gain. And, even if they polluted more, the pollution is centralized in the power plants, which is easier to do something about. There are problem health benefits from moving pollution away from population centers.

I make a point of going to parks with my EV. I know it's a token gesture, but I like to think I'm not blowing dirty fumes next to animal habitats. It helps that California is reasonably clean.

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#178

Post by outworlder »

rootusrootus wrote: post #137
DennisP wrote: post #111

Earlier quoted context omitted.

Probably true, but at the same time, some electric cars are pretty darn fun to drive.

Of currently available models, isn't that essentially ... one of them? And only in a straight line. Electrics have a ways to go before they're suitable candidates for things like track days.

Even a Leaf is fun due to the constant acceleration.

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#179

Post by DennisP »

rootusrootus wrote: post #137
DennisP wrote: post #111

Earlier quoted context omitted.

Probably true, but at the same time, some electric cars are pretty darn fun to drive.

Of currently available models, isn't that essentially ... one of them? And only in a straight line. Electrics have a ways to go before they're suitable candidates for things like track days.

Arguably the Model 3 isn't "currently available" but Motor Trend is a big fan for more than straight lines:

"The Model 3 is so unexpected scalpel-like, I’m sputtering for adjectives. The steering ratio is quick, the effort is light (for me), but there’s enough light tremble against your fingers to hear the cornering negotiations between Stunt Road and these 235/40R19 tires (Continental ProContact RX m+s’s). And to mention body roll is to have already said too much about it."

http://www.motortrend.com/cars/tesla/model-3/2018/exclusive-...

Re: SKYACTIV-X: first commercial gasoline engine to use compression ignition

#180

Post by sokoloff »

aunty_helen wrote: post #175
fnj wrote: post #104

Earlier quoted context omitted.

> a Tesla uses about 300 Watts a mile @ 55 Mph This is nonsense. The dimensions are wrong. Watts are instantaneous power. To be meaningful, you would have to give either kWh/h or kWh per mile or km. Besides that 300 W is only 0.4 hp. Sorry, but that is just not credible.

Not to dispute your claim that it's low, but the physics checks out. The cited link saves me explaining it: >Reports are 300 W/mile at 55 mph. If you do the product of these two numbers (300 * 55) all units but W will cancell eachother out so the answer is 16500 W = 16.5kW The time component being on the mph allows the conversion.

No. 300 Watts / mile * 55 mile / hour leaves you with 16500 Watts / hour, which is a non-sensical unit.

On the other hand, using the correct units (300Wh/mile):

300 Watt * hour / mile * 55 mile / hour = 16500 Watts [a sensible unit] (or about 22 horsepower which is reasonable for a steady 55mph cruise).

Do that for an hour, and you get 16.5kWh of energy consumption and cover 55 miles, for an energy efficiency of 3.33 miles/kWh, which is in the ballpark (albeit low) for what my LEAF delivers (averaging a bit over 4 miles/kWh at average speeds somewhat lower than 55 mph)

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