New MPG requirements

[xmech2k]

So then, why all the emphasis to keep building bigger and more powerful V6s and to upgrade cars as they get facelifts with bigger motors such as the 3.5 and 3.7 from Ford?

 

Because there is a market for them and people will pay the money for the auto companies to profit from them.

[akirby]

So then, why all the emphasis to keep building bigger and more powerful V6s and to upgrade cars as they get facelifts with bigger motors such as the 3.5 and 3.7 from Ford? 2016 isn't that far in the future and you would think we'd begin to see some of the alternatives sooner rather then later. Someone mentioned Diesel and yes, I would love to see some diesel alternatives in the cars we drive today. I'd also like to see some alternative vehicles driven by Hydrogen or even some solar charged cars as well. Hydrogen has allot of vehicle potential yet you don't ever hear any of the big auto Companies discuss this alternative. Why is that? Big Oil is the answer, Big profits, Big partnerships, Big back door agreements, etc. etc.

 

 

http://www.hydrogencarsnow.com/

 

Because that's what people want and companies that don't make what people want to buy go out of business. There is no "big oil" conspiracy. That's just an excuse for people who don't get what they want.

[EntropyAvatar]

I'm pretty skeptical that carburetors are the magic key to high fuel efficiency. I'm sure EPA regs have an impact, but I think it's mostly consumer habits and expectations. Safety design has definitely added to weight, but power has gone up even faster. Improvements in engine efficiency has gone to make engines more powerful, because, hey, why not? Gas is cheap enough and more power is more fun.

 

15 years ago my thermodynamics prof was seriously pissed that all the improvements in engine efficiency were being erased by changes in fleet composition. It looks like changes to the CAFE regs are going to put so many incentives on smaller/lighter/hybrid cars to change that fleet composition back a bit.

 

Well, years ago they used carburetors, remember those? Cars would get 35-40 MPG with those, BUT EPA regulations made the use of one obsolete.

[Oman]

The Atkinson cycle engine is the opposite of a turbo charged engine. The point of the Atkinson cycle is to reduce the compression cycle parasitic power loss.

 

What you would want to do is create the absolute lightest engine possible. This means having the minimum possible power that would make the car useful. A turbo helps with this as the amount of boost can be dynamically controlled. Then create the lightest car possible.

 

We can make 70MPG cars today. What we can't make is 70MPG cars that are as large, powerful, safe, and as low emissions as we have today.

 

 

 

For the FFH, they could find ways to reduce the weight, including the size of the battery.

 

It's also possible to add eco-boost to the hybrid design. I read a recent interview with a turbocharger engineer from Honeywell (Garrett turbos) who suggested this as a possibility -- turbocharging the gasoline engine in the hybrid.

[acdii]

I'm pretty skeptical that carburetors are the magic key to high fuel efficiency.

 

 

I didn't say they were, but when you look at what cars were getting back then, to what they get now on the same engine using FI, there is a difference. I had a 4 cylinder Isuzu P'Up, it got 32 MPG on a carbureted engine. That same engine now with all the emissions controls would get less MPG. They stopped using carbs because they were unable to regulate emissions to meet gov standards. I remember trying to get a mitusbishi carb to work, it had so many electronic things on it, that once something went bad, the darn thing barely ran. So now, one PCM can control the entire engine management system, with fewer components. Intake air flow measurements, exhaust gas temp, O2 levels, throttle position, fuel pressure, timing, and fuel injection metering. That last part is the key, without it, you can't control what exits the tailpipe, and that is where a carb fails. You can fine tune a carb outside of what the computer does, and that is where you can make it more efficient, but what comes out the tail pipe is more pollution.

[xmech2k]

I'd like to compare that 32mpg Isuzu pickup with a comparably sized modern one, and see what the weight difference is. What year was that?

 

Edit: Just looked on Edmunds at the 1990 and 1995 Isuzu trucks. They were rated 20-21 Hwy mpg.

Edited April 8, 2010 by xmech2k

[xmech2k]

:lurk:

[acdii]

I'd like to compare that 32mpg Isuzu pickup with a comparably sized modern one, and see what the weight difference is. What year was that?

 

Edit: Just looked on Edmunds at the 1990 and 1995 Isuzu trucks. They were rated 20-21 Hwy mpg.

 

It was a 1987 P'up, rated 21-28, I had mostly highway miles.

 

 

Specs

Edited April 12, 2010 by acdii