Why? Emissions regulations, that's why:
http://www.reuters.com/article/us-autoshow-paris-engines-exclusive-idUSKBN12E11K
Turns out more displacement isn't so bad for emissions in the real world, while the little turbo engines are better in artificial testing.
Poor WOT emissions are definitely nothing new for the small turbo gassers. Most of them run disgustingly rich from the factory to avoid self-destructing in the hands of average drivers. It's not uncommon for them to blow off a little bit of visible smoke when held at WOT for a couple seconds.
Guess there is no replacement for displacement after all
So there really is no replacement.
I think that boosted displacement is the answer
Wow, IMHO, that's a very simple and incorrect excuse of why.
SULEV30/PZEV at PM of 3 is really easy with small displacement and turbos. And the enrichment at WOT isn't nearly what you guys think. And that is a lower overall target than EuroVI is. The only part about EuroVI that is lower than here in the US is particulates- and in the EU, they do a number count that is very low. Other than that, the NMOG + NOx is lower for the upcoming LEVIII than the EU.
The problem is powertrain matching. You can only go so small with displacement to weight and meet realistic performance targets.
Three big changes to the EU rules are coming- 1) they are approaching LEVII/TierII, 2) the rules for diesel and gas are getting MUCH closer together (stressing diesels a lot, and in the US, diesel and gas have the same rules) , and 3) the drive cycle is changing from a really lame fake lab drive to a real on road cycle- a portable device will be attached to the car, and it will take a drive in the real world.
As I've posted before, this will pretty much doom small diesels for companies other than BMW and Mercedes, as the cost to get them that clean will make them cost ineffective.
I think another part in the equation is the PN standard- which is easy for a PFI motor to make, and hard for a DI motor to make without a filter. And DI is a key part of modern downsizing with turbos.
AIUI small-engines-with-turbos isn't driven so much by emissions as by fuel economy requirements.
In reply to alfadriver:
I will trust that what you said is knowledgeable and correct because I haven't a clue what you said 
Alfadriver:
Has there ever been a real study of an understressed low RPM, low power large displacement as compared to a high strung turbo small displacement engine within your walls?
We model performance on our stuff like crazy. I can only imagine that you guys do too.
My instinct tells me that they would be very close to each other in most real world reasonable scenarios (no 50CC turbo 2s compared with 9 liter V10s).
And what's old is new again. I can remember when cars, in the 90s-early 2000's went from smaller displacements (1.6-2.0l in cars like the Sentra/Protege, etc.) to larger (2.0-2.5l). It was all in the name of emissions... Easier to get the cleaner exhaust with a less stressed engine...
tuna55 wrote: Alfadriver: Has there ever been a real study of an understressed low RPM, low power large displacement as compared to a high strung turbo small displacement engine within your walls? We model performance on our stuff like crazy. I can only imagine that you guys do too. My instinct tells me that they would be very close to each other in most real world reasonable scenarios (no 50CC turbo 2s compared with 9 liter V10s).
The hardest of the hard part isn't making a lot of power, it's making very little efficiently.
In terms of power and torque, many of our small displacement turbos are better than their "equal" normally aspirated- mostly because boost means low end torque that is nice to drive.
But most of use normally use 5-30 hp on a normal day. That's it. This board will generally use more for honing, but if you just are doing traffic- 5-30 is all you really use.
And small engines do that better.
So the trick is making a small engine act like a big one (boosting) or a big engine act like a small one (turning cylinders totally off via valvetrain).
The discussion you speak of has been going on for years- trying to find the sweetspot of weight to displacement. Sometimes they do it pretty well, sometimes not.
codrus wrote: AIUI small-engines-with-turbos isn't driven so much by emissions as by fuel economy requirements.
That is true. But making small engines be very clean isn't that hard, in my experience.
But it does take some good engineering with great models and some well laid out prototype engines. The hard thing to convince people is that "if we've done X before, we can do it again." Dunno why people do that.
Wxdude10 wrote: And what's old is new again. I can remember when cars, in the 90s-early 2000's went from smaller displacements (1.6-2.0l in cars like the Sentra/Protege, etc.) to larger (2.0-2.5l). It was all in the name of emissions... Easier to get the cleaner exhaust with a less stressed engine...
I can remember in the early-mid 70s when engines got bigger and bigger because the automakers couldn't get them to run clean enough besides "make less power" so we had 120hp big block Chryslers and 180hp Caddy 500s and most cars made peak power at maybe 3500rpm, with super low compression.
Why doesn't anyone ever solve this problem with dramatically less weight to move around?
Huckleberry wrote: Why doesn't anyone ever solve this problem with dramatically less weight to move around?
That's a lot more difficult to do with modern crash test requirements and customer NVH expectations.
Woohoo! So now I can drive my carbed 1985 Chebby 350 Heavy Duty truck with a clear conscience! Nine mpg kinda stinks, though.
Does this mean ill be able to get a modern gasoline 460 again soon!
I always thought that the original Honda insight had it right. Small engine for cruising along and an electric kick for acceleration
Huckleberry wrote: Why doesn't anyone ever solve this problem with dramatically less weight to move around?
Mazda's on our side
Actually, I drove a Fiata home tonight. Small, highly boosted engine instead of the slightly larger naturally aspirated one in the Miata. Very, very different driving experience. That Fiat engine is no gem, it lags like you would not believe. I think 90% of the population would prefer the Miata engine outside of a short "open it up and see what she'll do!" test drive where the turbo can finally climb up out of the hole. Both cars (assumedly) meet the same emissions requirements, and I don't think they're all that different in terms of ratings.
Welp, I think that totally justifies putting a 500 ci Cadillac engine in a Prius
alfadriver wrote:tuna55 wrote: Alfadriver: Has there ever been a real study of an understressed low RPM, low power large displacement as compared to a high strung turbo small displacement engine within your walls? We model performance on our stuff like crazy. I can only imagine that you guys do too. My instinct tells me that they would be very close to each other in most real world reasonable scenarios (no 50CC turbo 2s compared with 9 liter V10s).The hardest of the hard part isn't making a lot of power, it's making very little efficiently. In terms of power and torque, many of our small displacement turbos are better than their "equal" normally aspirated- mostly because boost means low end torque that is nice to drive. But most of use normally use 5-30 hp on a normal day. That's it. This board will generally use more for honing, but if you just are doing traffic- 5-30 is all you really use. And small engines do that better. So the trick is making a small engine act like a big one (boosting) or a big engine act like a small one (turning cylinders totally off via valvetrain). The discussion you speak of has been going on for years- trying to find the sweetspot of weight to displacement. Sometimes they do it pretty well, sometimes not.
5-30hp is all most people use? To me this begs the question why isn't one of the automakers building this car? A small commuter with 30 hp that gets 80 to 100 mpg. Nobody here would want it, but I know there is a lot of people out there that would.
Also, keep in mind that at least in Europe, cars are taxed by engine displacement (at least other than the UK, where they're taxed by engine emissions or a flat rate if they're older). Those taxes can be pretty high, so there's an incentive to build cars with smaller, boosted engines.
D2W wrote:alfadriver wrote:5-30hp is all most people use? To me this begs the question why isn't one of the automakers building this car? A small commuter with 30 hp that gets 80 to 100 mpg. Nobody here would want it, but I know there is a lot of people out there that would.tuna55 wrote: Alfadriver: Has there ever been a real study of an understressed low RPM, low power large displacement as compared to a high strung turbo small displacement engine within your walls? We model performance on our stuff like crazy. I can only imagine that you guys do too. My instinct tells me that they would be very close to each other in most real world reasonable scenarios (no 50CC turbo 2s compared with 9 liter V10s).The hardest of the hard part isn't making a lot of power, it's making very little efficiently. In terms of power and torque, many of our small displacement turbos are better than their "equal" normally aspirated- mostly because boost means low end torque that is nice to drive. But most of use normally use 5-30 hp on a normal day. That's it. This board will generally use more for honing, but if you just are doing traffic- 5-30 is all you really use. And small engines do that better. So the trick is making a small engine act like a big one (boosting) or a big engine act like a small one (turning cylinders totally off via valvetrain). The discussion you speak of has been going on for years- trying to find the sweetspot of weight to displacement. Sometimes they do it pretty well, sometimes not.
you are reading it wrong. You use more to accelerate, but in steady state driving, you use very little HP
D2W wrote: 5-30hp is all most people use? To me this begs the question why isn't one of the automakers building this car? A small commuter with 30 hp that gets 80 to 100 mpg. Nobody here would want it, but I know there is a lot of people out there that would.
The Mirage is close, over 50mpg if you pay attention, and everyone here calls it the worst car ever. Clearly no one actually wants what they say they want.
D2W wrote:alfadriver wrote:5-30hp is all most people use? To me this begs the question why isn't one of the automakers building this car? A small commuter with 30 hp that gets 80 to 100 mpg. Nobody here would want it, but I know there is a lot of people out there that would.tuna55 wrote: Alfadriver: Has there ever been a real study of an understressed low RPM, low power large displacement as compared to a high strung turbo small displacement engine within your walls? We model performance on our stuff like crazy. I can only imagine that you guys do too. My instinct tells me that they would be very close to each other in most real world reasonable scenarios (no 50CC turbo 2s compared with 9 liter V10s).The hardest of the hard part isn't making a lot of power, it's making very little efficiently. In terms of power and torque, many of our small displacement turbos are better than their "equal" normally aspirated- mostly because boost means low end torque that is nice to drive. But most of use normally use 5-30 hp on a normal day. That's it. This board will generally use more for honing, but if you just are doing traffic- 5-30 is all you really use. And small engines do that better. So the trick is making a small engine act like a big one (boosting) or a big engine act like a small one (turning cylinders totally off via valvetrain). The discussion you speak of has been going on for years- trying to find the sweetspot of weight to displacement. Sometimes they do it pretty well, sometimes not.
I haven't checked the latest acceleration numbers on modern hybrids, but it seems to me that someone would build a car that used a small, efficient ICE to provide that 30 HP, and then kept a big honking electric motor on stand-by that could roast the tires if the driver so mandated.
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