Do Hybrids Really Make Sense?

[EVmetro]

So many people buy hybrids to either boost their fuel economy, protect the environment, or both, but how many of them actually understand the principles of physics and thermal dynamics? Are hybrids really any more fuel efficient than a regular full time gasoline burning car?

[cowmeat]

Are hybrids really any more fuel efficient than a regular full time gasoline burning car?

I struggled long and hard to reach 60 mpg in my Festiva. There are only a couple of people on this site (a site dedicated to ecomodding) who regularly get anything over that in their straight-up ICE's, and most of those cars are practically unrecognizable from their OEM state to get that kind on mpgs.

The day I bought my first Insight and drove it home I got stuck in a traffic jam and a rainstorm and had the AC blasting, and still managed to average 61 mpg. Since then I have learned to drive the Insight better and average in the high sixties, tank after tank.

There's a reason the Gen-1 Insights top the list of teams in the challenge. Not sure what your question really is.

[MetroMPG]

People will argue on the environmental question until the cows come home and ultimately believe what they want to.

But you can't argue that they save fuel vs. comparable ICE only vehicles for typical drivers, WHEN that's their design goal. While some hybrids have "performance" design goals, or "too mild" hybrid systems, and the fuel savings aren't there.

[cowmeat]

I feel the difference every time I pass the gas station on my way to another 600+ mile tank, so I'm as convinced as I need to be, lol.

If I had a shorter commute maybe I'd swap to a full EV, but as far as realistically attainable vehicles versus my daily commute, I think I'm about maxed out.

[EVmetro]

I have noticed that Hybrids typically come with instrumentation that could show a driver how to drive more efficiently, and that many hybrid owners are interested in conserving fuel. I have also noticed that people in this forum have reported significant gains in their fuel economy since installing a scangauge or comparable instrumentation, and like many hybrid owners, the people who use a scangauge are interested in boosting their fuel economy.

What I am concerned about, is that I can't find any actual data that supports hybrids being able to be more efficient. I am not talking about mpg claims, I am talking about science. What technology makes a hybrid any more efficient than the comparable ICE?

[MetroMPG]

What technology makes a hybrid any more efficient than the comparable ICE?

The basics:

1) Hybrids have a downsized ICE vs. a comparable non-hybrid = more efficient when running.
2) Hybrids kill the ICE when propulsion is not required (coasting/when stopped) = more efficient in those scenarios.
3) Regenerative braking (and coasting) captures energy for later use that would otherwise be wasted = more efficient than no regen.
4) Many hybrids permit limited, low speed electric propulsion, rather than ICE propulsion = more efficient again.

[cowmeat]

Here's how the Insight hybrid technology works:

Let's say you have a wagon pulled by a horse (ICE).
The horse can pull it from a dead stop of course, but he's really only comfortable plodding along at speed, that's where he is at his best.
So you hook up a pony with him (IMA) and the pony helps get the wagon rolling from a dead stop, pulling as hard as he can to get the wagon up to speed. The pony tires out quick, but he helps keep the horse fresh for the long haul.
When the wagon is cruising at speed, the pony jumps up in the wagon with you and the horse happily pulls you down the path.
When the wagon slows down, the pony jumps back out to eat, and the horse and pony both get some rest when you stop.

[EVmetro]

Originally Posted by MetroMPG

1) Hybrids have a downsized ICE vs. a comparable non-hybrid = more efficient when running.

This makes good sense. What if you took that smaller motor and put it in the comparable ICE, minus all of the Hybrid related technology?

Originally Posted by MetroMPG

2) Hybrids kill the ICE when propulsion is not required (coasting/when stopped) = more efficient in those scenarios.

Killing the engine when it is not needed makes good sense. What would happen if you killed the engine on the comparable ICE as well? Efficient fuel management does not need to be unique to hybrids, does it?

Originally Posted by MetroMPG

3) Regenerative braking (and coasting) captures energy for later use that would otherwise be wasted = more efficient than no regen.

There certainly is waste energy to be harvested, but how much of it is actually harvested? What penalties come from hauling around the waste energy harvesting system? Once the harvested energy is collected and then depleted, you have no waste energy to use, so how does it get replenished? How much additional gasoline is needed to haul this system around or to recharge it when one is traveling long distance?

Originally Posted by MetroMPG

4) Many hybrids permit limited, low speed electric propulsion, rather than ICE propulsion = more efficient again.

This makes good sense. This is not available on an ICE car, but is this enough to offset the efficiency that the ICE version would have if it was equipped with the smaller more efficient motor and the reduction of weight and rolling resistance?

[Fat Charlie]

Then there's marketing. I mean styling. I mean aerodynamics.

Because hybrids tend to be marketed as efficient, stylists have to make the cars look it, so we get the "hybrid look." The marketing folks won't let other cars be aerodynamic because that'll dilute the "I'm Efficient" look that they've assigned to hybrids.

[EVmetro]

Is there anything unique to a hybrid other than the ability to harvest and redistribute wasted braking energy that can't be done on an ICE?