lne937s wrote:Back to the previous discussion, there are performance benefits to older technologies in some circumstances. But it is often a cost/complexity-related benefit and what people are willing to pay for. The US military, for example, shifted to independent suspensions for their light off-road vehicles over 30 years ago (Humvee, etc.), but cost isn't as much of an object and they are willing to pay for measured performance improvements. The Wrangler, by comparison, keeps its solid axles for a more traditional consumer market.
Sure, but I think this is also a great demonstration of my point. Solid axles are still best for certain things. Independent suspension is best for certain things. Each comes with costs and benefits. Because one works well on one vehicle for one purpose is not proof that that one tech is the One True Tech.
Cost is sometimes a factor in solid axle configurations. But other times things like packaging, simplicity, modularity, or durability are the deciding factor instead. For instance: 1st generation Maxima sedans had Z-derived IRS, but the wagon had a solid axle to allow for a lower, wider load-floor.
Meanwhile, modern pickup trucks combine the benfits of IFS with the benefits of a solid axle in the rear to get the best of both worlds in most use scenarios. Many people still convert to solid axles in the front, though, for specific types of use.
An independent suspension setup has more moving parts, more structural parts, and more complex geometry than a solid axle setup. You need a differential mounting member, you need one or two sets of CV joints, you need to anchor the hub while maintaining good tire geometry--essentially, you need a subframe and control arm. For a solid axle, you just need springs and shackles and the rest sorts itself out. In some applications, the benefits of the more complex design far outweigh their cost in complexity. But in others, they absolutely do not. So both are used, and both are desirable.
lne937s wrote:On the other hand, sometimes, superior technology is abandoned due to cost. Offy's used unitized block and head with separate crankcase... but the construction was expensive to machine and largely eliminated when reliable head gaskets and stronger heads were developed. We now see a unitized block/head reappear in the ZEOD's engine, and hopefully new machining technology brings it back, but it went out of style due to production cost/complexity, not performance.
And that that point the question becomes: is it worth the extra cost/complexity right now to go this route, or are the drawbacks relatively manageable enough to ignore that tech in some products?
And this is why it's cool to see someone pushing boundaries even when it doesn't really make sense. Like early modern electric cars, or hydrogen cars. Both of them were "bad" ideas and bad business cases on the surface, but they helped us get the core tech and (often more importantly) supporting tech to a point where it could evolve and improve so that, down the line, it might be something worth practically considering.
lne937s wrote:The overall point is that we should keep an open mind on new technology: not that new is automatically better but definitely not that old ways are automatically the best ways.
Right, and this was really my point. Old or new, who cares. What matters is what it does. So ignoring what worked in the past because something new came along and ignoring what's new because it's scary and different are equally foolish. However, ignoring something new because it doesn't actually work is an entirely valid mentality.
lne937s wrote: In the big picture, CVT fluid cooling seems like a fairly simple engineering challenge to overcome. But to tackle that challenge, there needs to be a market willing to pay for it and the potential to keep the costs down to the point where it is profitable.
Seems like is sort of my point. As I said, we're ~12 years into the livespan of common consumer CVTs, and this is still a problem. If it were as simple a solution as it seems, we'd be past it by now. So either it's not that simple, or nobody's willing to invest enough to figure it out. And if it's the latter, what does that say about the overall perception of CVTs from an engineering perspective?
And as far as "consumers are stubborn and buy what they want" I wholeheartedly disagree. Auto consumers in general are unknowledgeable and need to be told what they want. This is why Lexus and Toyota dominate. This is why manual transmissions are hard to find. This is why Nissan gets away with terrible CVTs in everything. Consumer demand is NOT a factor in the continuing validity of traditional automatics in the market. Cars with CVTs sell just fine. Cars without sell fine, too. The difference is that one works the way it needs to, and the other is a fledgeling tech that nobody is yet convinced is actually capable of its potential.
