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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

#221

Post by lps41 »

Shivetya wrote: post #216
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…

What they should be doing is showing changes to range and costs throughout the year. During mild to warm months my EV range on a Volt is much better but come winter. Same goes for pure EVs. Pure EVs are not truly viable even with the Tesla network for long trips, once past a two charge trip you timing has to be truly altered and it gets worse in hilly country or winter. Now in winter gasoline/diesel cars have the iss…

I think the long-trip problem is solved by families owning one gas or hybrid car, and one pure EV car. Or even two pure EVs, and planning to rent a gas powered car for long trips!

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

#222

Post by sergiosgc »

icc97 wrote: post #195
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…

Electric cars are the real world example of loose coupling. Once your car is electric the source of the electricity can change (from Coal -> Gas -> Solar) and you don't have to change your car even slightly. So it doesn't matter about any of the arguments about whether an electric car is more efficient or not when the electricity comes from coal. What matters is that having electric cars enables us to move to a futur…

> Plus having electric cars that don't pollute in cities where there are lots of people and generating the electricity with coal fired powerstations outside of cities where there are less people has immediate benefits.

While this is true, much as the rest of your comment, this sentence has made me think that pushing pollution away from the eyes of people is a really negative effect of electric cars. If pollution is not in my backyard, I'll certainly be less aware of it, and hence I'll certainly pressure less for reduction.

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

#223

Post by JshWright »

bgarbiak wrote: post #205
icc97 wrote: post #195

Earlier quoted context omitted.

Electric cars are the real world example of loose coupling. Once your car is electric the source of the electricity can change (from Coal -> Gas -> Solar) and you don't have to change your car even slightly. So it doesn't matter about any of the arguments about whether an electric car is more efficient or not when the electricity comes from coal. What matters is that having electric cars enables us to move to a futur…

I'm as big fan of EVs as the next guy, and would love to see cities with clean air and no noise. But, there are few things that we forget about when we talk about zero-emmision cars. EVs pollute less, but they pollute too, and in cities as well. They emit dust (including the most harmful particles: PM10 and PM2.5) from break discs and tires. Difference between CO2 in power plants and in city centers matters, but not…

> Add a fact that in the current grid setup most of the energy is coming from coal

Coal represents less than a third of North American power generation, and less than a quarter of generation in Europe. In Brazil (another major car owning country) coal only represents ~1% of their generation sources.

Really the only place your statement is true is mainland Asia, and even there the market share of coal is falling (and the number of cars there is dwarfed by the number in NA/Europe/Brazil).

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

#224

Post by neogodless »

raman325 wrote: post #162
mywittyname wrote: post #127

Earlier quoted context omitted.

> Blows any hybrid out of the water for total COO. Not so sure about this. I have a 2014 3i GT and my wife has a 2014 Prius. Hers was cheaper to buy, gets way better mileage (29 v. 44) and needs less frequent oil changes (which are free), and is worth about $1200 more now. It's a little faster, nicer inside, and much more fun to drive. But cheaper, nah.

I'd assume the parent comment is referring to the base package version of the Mazda 3. I was able to get a 2015 Mazda3 S Touring for ~$25k with all taxes and fees included, so I think $20k is a fair estimate if you assume the base package

Indeed. I was shopping recently and the 2017 Sport was going for under $18k with current Mazda incentives ($2k cash.)

(I ended up with a 2015 S GT for $20k - only 8k miles on the odometer :)!)

Also - that's an i (2.0L) which gets 30/40 mpg (about 34-35 overall) so not quite the stark difference in fuel economy compared to a Prius that the 2.5L has.

(gallons per 100 mile difference between 35 mpg and 44 mpg is 2.86 vs 2.27)

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

#225

Post by kw71 »

_wmd wrote: post #213
bovine3dom wrote: post #212

Earlier quoted context omitted.

> From a macro perspective the gain for environment is on par, if not better, than from electric cars. Citation needed. It seems obvious to me that a huge power plant is going to be less polluting per kWh than a tiny little engine in a car. Otherwise, we'd use tiny little car engines to power everything - which only happens at the moment in places where they cannot get electricity by other means (building sites etc).

Don't forget that electrical grid transmission losses cause massive efficiency problems before centrally generated power ever reaches that car charging point -- on the order of 30% or more, and conversion from AC to DC at the charging port may account for another 10-30%. (Made up numbers, but they're in well within range IIRC) I don't think it follows that just because we have historically centralized power generatio…

> conversion from AC to DC at the charging port may account for another 10-30%

Simple rectification has not so much loss, I think you are thinking about low voltage DC power supplies, and I think that chargers for large, high voltage battery piles are likely to be happy with rectified (maybe doubled) mains supply.

The low voltage supply is first rectifying the input, then using an inverter to generate high frequency AC, then rectifying and filtering this to give a DC output.

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

#226

Post by _archon_ »

busterarm wrote: post #51
mchannon wrote: post #31

Earlier quoted context omitted.

Owned one. Enjoyed the heck out of it. Lots of torque, lots of pep, though from what I heard, the US version (mine) had substantial increases in pollution controls which hobbled the car. Always first off the line when I wanted to be. Yes, it burned oil by design. I'd add a half-quart of non synthetic 5W-20 maybe every 1000 miles. The rear bumper required additional car washes, as it'd get a black film, no doubt from…

> The fix was to have it towed to the dealer where they'd clean out the engine for a few hundred dollars. Later I learned you could tow-start it if you could get it up past 20mph. It'd put all kinds of foul smoke out the back when you did that but in terms of hassle, it was much better. You don't need to do all that. You can just pull the EGI INJ & EGI COMP fuse, crank it for a few seconds, replace and start it up. M…

On the RX8 at least, if you hold the gas pedal to the floor while cranking, it disables the fuel injectors. No need to pull fuses. * Foot to floor, crank for 10 sec, * let it rest for 30 sec to cool off the starter, * foot to floor and start to crank, pull your foot off the gas pedal.

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

#227

Post by _archon_ »

toast0 wrote: post #39
mchannon wrote: post #31

Earlier quoted context omitted.

Owned one. Enjoyed the heck out of it. Lots of torque, lots of pep, though from what I heard, the US version (mine) had substantial increases in pollution controls which hobbled the car. Always first off the line when I wanted to be. Yes, it burned oil by design. I'd add a half-quart of non synthetic 5W-20 maybe every 1000 miles. The rear bumper required additional car washes, as it'd get a black film, no doubt from…

> before the stork came and the rotary had to leave One of my friends had an rx-8, the backseats were useless for adults, but glorious for car seats.

I have an 8 (and am involved in sports car things as a hobby) and I find the back seats to be superior to almost all sports cars and most mid-sized normal cars for seating adults.

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

#228

Post by _archon_ »

busterarm wrote: post #53
quake wrote: post #16

Earlier quoted context omitted.

More or less usable. They did have a tendency to blow apex seals after 80k miles, which was could end up as a full rebuild of the engine. As far as how finicky a rotary can be, the biggest thing to do is let them warm up before driving, and let them cool right down after you're done. They were never an engine to replace the standard fourbanger, but they weren't any more finicky than say a BMW or Audi at the time of t…

My FC has 112k miles on the engine without a rebuild. Still has good compression, but on the low side of good. Pull and rebuild is pretty easy though.

My 8 made it to 127k before compression mandated a rebuild, and one of the previous owners is a documented idiot. Been solid ever since.

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

#229

Post by _archon_ »

ynniv wrote: post #25
quake wrote: post #16

Earlier quoted context omitted.

More or less usable. They did have a tendency to blow apex seals after 80k miles, which was could end up as a full rebuild of the engine. As far as how finicky a rotary can be, the biggest thing to do is let them warm up before driving, and let them cool right down after you're done. They were never an engine to replace the standard fourbanger, but they weren't any more finicky than say a BMW or Audi at the time of t…

weren't any more finicky than say a BMW or Audi at the time of the RX-8 YMMV, but my E46 BMW has been very reliable compared to an RX-8 bought at the same time. Audi was still in the process of applying the lessons of the RS4 to their everyday cars, but I still wouldn't call the RX-8 reliable compared to its peers. As you hinted, there are a couple of problems that lead to full rebuilds before 150k miles.

Mazda shot themselves in the foot reliability-wise with the first generation RX-8 because they:

* Underspec'd the ignition coils

* Didn't do enough on-road reliability testing

* Lowered the oil pressure and removed OMP ports

* Designed the oil filler breather in a way that allowed oil into the intake

In '04, the first wave of RX8s were coming in to the dealerships after 30k with severe misfire from the coils going bad. Mazda didn't have this failure mode in their factory service manual, so the cars got replacement engines (poorly reman'd in Mexico, not made on the Mazda Japan line). These didn't last because of poor manufacturing. Once the coil issue was figured out, the 8 became much more predictable and reliable.

As noted by Busterarm, they fully got their act together with the series 2 update.

[I own an '04 RX8 with ~130k miles)

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

#230

Post by _archon_ »

ticklemyelmo wrote: post #88
aidenn0 wrote: post #83

Earlier quoted context omitted.

Almost certainly not, as diesel and gasoline have very different self-ignition properties.

I wonder whether this engine will specifically require you to fill up with NON-premium gas.

I anticipate the engine's control computer will be able to adapt in any case. It's like the Mercedes driver who puts in 87... it'll work, and the gas is cheaper, but the tradeoff is the engine runs in "poor fuel" mode and is less efficient, eliminating any savings.
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