Electric Cars Push Japan Engine Parts Makers to Crisis Mode

[SentraSE-R]

Originally Posted by jamesqf

Well, your assumptions are wrong. It's just simple fact that if you put a gas engine in a hybrid, and run it at its most efficient speed, you'll get far better mpg than the same car with just a gas engine.

Think about your statement. It can't be true from a logical standpoint.

[tjts1]

Originally Posted by jamesqf

Well, your assumptions are wrong. It's just simple fact that if you put a gas engine in a hybrid, and run it at its most efficient speed, you'll get far better mpg than the same car with just a gas engine. And if you have reasonable plug-in battery capacity, you get better fuel economy still. Given the limits of current technology, that's where the optimum is.

[jamesqf]

Originally Posted by SentraSE-R

Think about your statement. It can't be true from a logical standpoint.

Sure. And bumblebees can't fly, and the sun goes around the earth :-)

I'm curious as to what sort of logic says it can't be true, though. Before answering, think about the following:

1) The efficiency of an internal combutsion engine varies considerably with speed and load. (See all the threads with BSFC in the title.) They're seldom driven at their highest efficiency, but if you have one in a PHEV, you can always run it at best efficiency.

2) The engine of an IC-only car needs to be considerably oversized to allow for acceleration and hill climbing, therefore it will be larger & heavier than one designed to run at constant speed.

3) If my typical trip is say 70 miles, and I have a battery pack that can take me 35, I've doubled my average mpg right there,

4) A lot of my driving is in the mountains. With a hybrid, I can capture a lot of the energy that'd otherwise be wasted in braking on the downhills.

5) If I had a PHEV, I'd also have a strong incentive to put solar panels on my roof to charge it, thereby eliminating a lot of indirect fossil fuel use. (My $50/month average electric bill isn't reason enough.)