# Hybrids aren't electric cars & aren't meant to be.



## nliwilson (Feb 6, 2011)

It astonishes me just how few people get the point of hybrids as a product. When you put a small engine in a useful sized car, contrary to assumption & manufacturer's BS, it usually results (out in the real world) in _increased_ not decreased fuel consumption because small engines lack torque and as a result you have to work the engine very hard, stepping on the throttle pedal (accelerator) hard more of the time. Electric motors on the other hand produce huge torque for their size but lack power, so by combining _both_ you get a small, frugal engine that can be given a big boost in torque when needed, that's why Honda refer to their hybrid system as "IMA" "Integrated Motor _Assist_."

The Prius' manual "EV Mode" (Electric Vehicle Mode, electric power only mode) button allows you to drive at a maximum of 31 mph for a _maximum_ of 1.2 miles, you can't drive across town on electric only because you'd need (approximately) another half ton of batteries and FYI; that's not an exaggeration, I literally mean half a ton, minimum!

Honda didn't bother with a manual electric option because only switching to electric power only mode when the computer knows it'll do the job properly means it can switch to electric only more often as it's not continually trying to build battery charge back up from minimum because the problem between seat and steering-wheel keeps pressing the freakin' EV button! 

Hybrids aren't electric cars and they aren't meant to be electric cars! They're petrol cars that can significantly reduce fuel consumption (and therefor emissions) by supplementing a gutless small petrol engine with an electric flywheel motor.


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## nliwilson (Feb 6, 2011)

Probably should mention that hybrids do more than just supplement a small petrol engine with an electric flywheel motor to improve efficiency. Both the Insight and the Prius use carefully chosen materials to save weight and a "fastback" body to improve aerodynamic efficiency. All hybrids can switch automatically to electric power only at steady speeds over short distances, use engine stop-start technology (which seems to confuse people even though it's been around longer than hybrid technology?!), use low energy tires and supplement the resulting loss of grip with electronic driver aids and (& this one really confuses people..) efficiency oriented climate control which both prevents over use of the fans & AC but also creates a more relaxed, comfortable driving environment, which is conducive to a more relaxed and economical driving style.

On that last measure, you'd be surprised just how much difference psychology makes. I've already covered the clever instrumentation in the Insight on another thread, but if you draw on your own experiences you know that drivers who are hot, cold and/or sat in a humid car are PO'd at being there and tend to drive more aggressively because they just want to get where they're going and get out. Making the driving environment a nice place to be encourages drivers to sit back and relax, even in traffic and that encourages people to take it easy rather than ramming the accelerator in to the carpet at every opportunity.


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## MN Driver (Sep 29, 2009)

I'll quote the biggest part of what you said that is incorrect.



nliwilson said:


> When you put a small engine in a useful sized car, contrary to assumption & manufacturer's BS, it usually results (out in the real world) in _increased_ not decreased fuel consumption because small engines lack torque and as a result you have to work the engine very hard, stepping on the throttle pedal (accelerator) hard more of the time. Electric motors on the other hand produce huge torque for their size but lack power, so by combining _both_ you get a small, frugal engine that can be given a big boost in torque when needed, that's why Honda refer to their hybrid system as "IMA" "Integrated Motor _Assist_."


Not quite. It results in decreased fuel consumption. You don't work the engine very hard stopping on the throttle hard. It works the engine near full load which gives you better fuel economy than partial load. When you press the throttle farther than what the gas engine is capable of producing additional power you get assistance from the electric motor to provide the extra torque needed for the situation. While you are traveling on the highway, the engine runs at 80% or so load and when climbing a hill you either use the battery power or drop down a gear or two. This way you can drive at 70 miles per hour at 70 miles per gallon. It is what allowed me to drive 630.5 miles on 8.592 gallons of gas, which is 73.4MPG with plenty of gas to go a little over 100 miles on the same tank if I wanted to.

Ideally engines would be sized to meet the load, the 1st Gen Insight is about the only car made to do exactly that by using a 1 liter gas engine, 1900 pound aerodynamic body, and two overdrive gears. It has plenty of power if needed by shifting out of overdrive and into third gear if you need it and I've been able to climb the I80 mountains without dropping under the speed limit. The electric assist is there to provide extra power so the engine doesn't seem small while accelerating hard or dealing with higher than average load. Most of the time I don't need that extra power and opt out of using it.

Other features such as engine auto-stop, being enabled to use a DC-DC converter instead of an inefficient alternator, and having regen help to provide extra MPG. I drive mostly on the highway, having the small engine, which also has lean-burn capability enables another 15MPG or so while cruising on the highway compared to a larger engine that would provide the same output as both the smaller engine and the electric assist combined.

Another part of what you said:
"Honda didn't bother with a manual electric option because only switching to electric power only mode when the computer knows it'll do the job properly means it can switch to electric only more often as it's not continually trying to build battery charge back up from minimum because the problem between seat and steering-wheel keeps pressing the freakin' EV button! "

Not quite, the Honda is a simpler design and when the electric motor moves, the engine moves because they are mated together so if you were to power the car electrically and drag the engine into rotation, it would be more inefficient than using the engine. It's better to speed up with the gas engine, kill the gas engine and coast down a little, fire it back up and repeat. ...even with a Prius.

...I disgress however, the 1st Gen Honda Insight would be the most efficient electric car if converted due to its light weight and aerodynamic design, not to mention a rust-proof body to go along with electric reliability. I will eventually convert mine.


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## toyolla2 (Jun 21, 2010)

to MN DRIVER +1

to NLIWILSON, I think you are being somewhat hard on the consumer.

I would say that few who purchase a Prius are knowledgeable that besides the battery happening to be of NiMH chemistry it is also intended as a POWER battery rather than an ENERGY battery. Despite its cost of $2300 it holds merely 1.3 Kwhrs compared to a run-of-the-mill $100 lead acid which holds around 0.9 Kwhrs. It does however explain why the Prius gives barely less than two miles at a 42mph in pure electric mode. (Consuming around 300Whr per mile) as you pointed out.

Of course this same battery will supply at a level of 21Kw of continuous power for short periods when called upon. Try getting that from your under_the_hood car battery ! This 28Hp of additional power helps the 1.5L engine achieve the same level of acceleration performance as a 2.4L Camry engine. Incidentally both Camry and Prius are classified as mid size vehicles.

I do agree that the Prius is not about being an electric car. It is in fact all about the advantage of an electric transmission. The ability to be able to run a gasoline engine in its high torque mode. While the engine is running, powerful servos MG1, MG2 keep the engine at the point at which it is almost lugging. The Engine Control Unit ensures the engine is compelled to run at the minimum rpm for any specific power delivery thus substantially reducing the engine friction per unit of power delivered.
That hasn't stopped some from demanding that Toyota PHEV this vehicle into an electric car. Time will tell whether this 2012 model Prius will see many sales. Personally I doubt it.


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