The Future of Cars

[serialk11r]

Discuss stuff like fuel economy, hybrid, future engine tech, alternate fuels, alternative forms of propulsion, and future performance enhancements and other technologies. Thought it might be a good idea cuz discussions tend to go in that direction on other threads sometimes.

I'll give it a start: I think it's pretty nice how they're coming out with variable lift systems, it's a major step since it enables a huge efficiency gain under part load without sacrificing maximum torque. I also think gasoline, or liquid fuel/natural gas or something will be around for a while, since the infrastructure needed for hydrogen doesn't exist and battery technology is not at the point where we can get the kind of convenience we expect from our cars. Thus, I think we'll start to see more hybrids coming, but in the form of mild hybrid systems of some sort. With lithium ion batteries it's possible to add nearly no weight by replacing alternator and starter with a single electric motor and small battery pack. They could also go with a second motor directly driving the wheels, which has the benefit of faster starts from a dead stop and reduced clutch wear.

[Midship Runabout]

Hybrids and electrics are just a fad. Diesel is the future in my opinion.

[Dimman]

I'm curious why Toyota hasn't put together a HSD system with a super-efficient common rail diesel yet.

[serialk11r]

Diesel has trouble passing emissions, that's why we don't have them over in America at least...Particulate emissions and NOx are the tough ones to solve I think. Also I read that US diesel has a ton of sulfur (our gasoline does too apparently sigh...) which makes things even worse.

I think people don't like the word hybrid since it's associated with the ugly ass Prius, but a lightweight mild hybrid system can be a benefit in every way (aside from cost).

[Dimman]

Originally Posted by serialk11r

Diesel has trouble passing emissions, that's why we don't have them over in America at least...Particulate emissions and NOx are the tough ones to solve I think. Also I read that US diesel has a ton of sulfur (our gasoline does too apparently sigh...) which makes things even worse.

I think people don't like the word hybrid since it's associated with the ugly ass Prius, but a lightweight mild hybrid system can be a benefit in every way (aside from cost).

The Honda system would probably be a better application with a diesel. The Germans are bringing over more and more diesels, but aside from VW they are $$$ cars. Also I think the US fuel is pretty close to being up to spec with the sulfur. They were planning on phasing in low sulfur over a certain time period or something?

I'm actually pretty impressed with Ford at what they are doing technically to get more mileage out of the Focus and Fiesta. But so far no diesel or entry level hybrid.

Toyota should do an inexpensive mild hybrid and/or diesel Yaris if they want to stay ahead of the compact competition.

[serialk11r]

I think one thing manufacturers can do that's VERY cheap and easy to boost fuel efficiency is to add low lift, low duration cams (essentially atkinson cycle, but maybe not as aggressive). Consumers will understand that this is the cheap way to get better mpgs, and it comes at the cost of grunt, but how many Yaris drivers do you see flooring the throttle? They could even make it like, further reduced duration on the low speed cams for VTEC and VVTi. It's cheaper than continuously variable lift at least. I think it's a bit weird how car manufacturers assume Americans want more grunt even in a cheapo car. The rest of the world does fine with smaller engines... If that's really what the market is, then maybe people need to start rethinking their priorities. Can't have it all...

[Infernal]

diesel has been around in europe (the uk at least) for a while and is still not as popular as the petrol options - co2 emissions per bhp are very low though, so it makes a good move.

diesels don't sound nice either, and only have a small rev range - granted, lots of torque but it's not an engine for sports cars really

i think electric cars will get better and better - look at the first motor cars they were 24 litre monsters that could barely reach mph into the 20's

now, a 1 litre car can go well in excess of 100 mph

battery technology is what is holding it back...

hydrogen cells are interesting also. but much further away technology wise than electric

[Ryephile]

Right now most propulsion-system technological progress is stunted by politics. As such it's very tough to make an educated guess beyond a few years.

In the very near term, Hybrid and electric systems are all the rage at the expense of long-term sustainability. As battery and motor technology improves [more efficient, better long-term recycle-ability] these will become a better idea.

Camless engines are another excellent idea. Chrysler did a boatload of R&D on pneumatic valve actuation back in the 80's but then shelved it because at the time it was too expensive. Now, it should be back on the table. Infinite valve lift and timing through servo/pneumatic control is the way forward as it has essentially ideal valve control and virtually no frictional losses. BMW's Valvetronic+VANOS was great last decade, but purely mechanical camshaft-derived actuation is old hat for what needs to be next-gen.

I'd like to see emissions standards modified to promote Diesel and HCCI gasoline and dissuade normal gasoline engines. Diesel is the cheapest and simplest way to achieve good efficiency right now. HCCI gasoline is a big step forward for gasoline engines, but their viability is very complicated in terms of processing power. Next generation ECU's will have enough processing power and speed to run HCCI engines, so there's hope.

Beyond that, there needs to be a big breakthrough in infrastructure, technology, and politics to move automotive propulsion systems forward.

[Matador]

BMW's valvetronic and now Toyota's valvematic, Nissan's NEO VVL and Honda's AVTEC does the same thing.... Infinite valve lift and timing. Pneumatic systems are still very expensive and are what you find in formula one engines. It's extraordinary for high rpm operation, but what benefit would it have on engines that rarely ever go beyond 6500rpm?

[Ryephile]

No, they don't do exactly the same thing. They are relatively primitive, slow, and limited in adjustability in comparison. A big improvement can be had in frictional loss and obtaining ideal valve actuation timing, duration, and lift with a camless system. A camless engine will be able to have fuel efficiency and torque levels that are currently not seen together. Add in WBO2, HCCI, very high pressure direct injection with shaped-combusion pistons, and turbocharging and you have a bill of materials for a state-of-the-art gasoline engine.

It also opens the door for high-RPM operation for production engines. Sprung valve-train is the #1 reason engines are stuck at relatively low RPM, with rod ratio being #2 reason.

The benefit of high RPM operation is usually in improved combustion efficiency through improved induction velocity and swirl turbulence.

[WhiteKnight]

what about the turbine system jaguar's developing?

[serialk11r]

Turbines are very, very loud, and have a narrow range of efficient operation so they can't be used as a standalone power source.

[WhiteKnight]

i don't know exactly how they're pairing it but that new jag is a hybrid with turbines...

[serialk11r]

Right, turbines that run to charge batteries or provide extra power. They only run when needed, not continually, which solves the part load efficiency problem, but I don't see how they're dealing with noise.