Comparing the prius with other hybrids

I disagree with the premise that Prius contains significant design features that other Toyota hybrids lack. Camry Hybrid, Highlander Hybrid, and the various Lexus hybrids all have the same basic hybrid architecture as Prius; however the powertrain output is scaled up to meet the perceived market demands faced by the different models.

The main Prius design feature that the other Toyota hybrids lack is the fuel tank bladder in North American models. I would venture to say that most Prius owners could do without said bladder.

The Ford Escape Hybrid has similar hybrid architecture as Classic Prius.

The GM hybrids are varied. Some models are barely hybrid and don't really deserve use of that name; however the more recent SUV hybrids have an architecture that is not embarrassing to GM.

 

Patrick Wong's post suggests to me that one might more profitably ask in what ways the Toyota hybrids as a group differ from other folks' hybrids, and perhaps in what ways the Prius is unusual not directly related to its hybrid power-train.

I'll offer up one characteristic of each type, subject to extension (and correction) by others who know more.

1. I think the specific clutchless planetary-gear power transfer implementation in the Toyota hybrid systems is distinctive. It certainly is quite different from conventional automotive systems of the 1990s, and I suspect most other manufacturers use a considerably different approach even in their hybrids.

2. I think the Prius external design makes a more successful special effort to lower air drag than almost all others. Probably the original GM EV-1 (electric), and the first generation Honda Insight (hybrid) bettered its drag coefficient, and they almost certainly had lower drag (proportional to the product of the coefficient and the frontal area) because of their smaller size and capabilities. But for its combination of passenger and cargo-hauling capacity, I suspect the Prius is a real standout performer on air drag among current production vehicles.

 

Ford Escape Hybrid has an engine and transaxle design that is similar to Toyota Prius (Atkinson cycle engine, electronically controlled "CVT"). I understand that Ford and Toyota have cross-licensed each other to use similar hybrid technology.

The Nissan Altima Hybrid is basically a Camry Hybrid wannabee, again with a design licensed from Toyota.

Honda and GM have their own hybrid designs; and I'll leave it to advocates of those systems to point out what's great about them.

 

You can go here for information on how the Honda Civic Hybrid, HCH, works:

http://priuschat.com/forums/honda-civic-hybrid/42725-civic-5-sp-manual-hybrid-how-does-work.html

 

The whole shape of the car, the more effective use of interior space (especially cargo) and such are the defining characteristics that I see. The Prius is the complete package while others are retrofits. Some are very good retrofits, but as retrofits there are compromises.

 

I believe that regenerative braking is absolutely the norm in hybrids -- so much so that it would be rather bold to call one that lacked it a hybrid.

Electric air-conditioning however is not universal. After all, even the Prius did not have it until the third generation model. I believe the Ford escape does not have it currently, and I am almost sure that the General Motors mild hybrids will not have it.

 

This is not an all-inclusive list by any means but there are benefits to each of the 4 major hybrid systems...

Honda's IMA is a very elegant and inexpensive engineering system that nearly accomplishes what the HSD does as long as the vehicle weights are kept below a certain level.

Toyota actually has two HSD systems. The Atkinson cycle system in the Prius and TCH and the Otto cycle system in the HH and the Lexus models. One for primarily for fuel economy and one for performance with a moderate improvement in fuel economy.

Ford's hybrid sytem is very close to Toyota's. It is very effective in midsized vehicles.

GM actually has two system also. The BAS mild hybrid system in the Vue, Malibu is very very inexpensive and gives a small boost to fuel economy. The 2-Mode system is something Toyota wishes it had for it's heavier vehicles today. The 2-Mode does for GM everything that the HSD does for Toyota's midsizers. It also addresses the worst characteristic of the most inefficient vehicles on the road today ( City driving by large BOF vehicles ).

All four systems as they stand today are very very good for all of us.

 

By heavier, you mean needing a tow-capacity greater than 3,500 pounds. Fortunately, that's a very small market... especially when you factor in the influence of diesel.

Put another way, HSD is by far the most competitive. It can be cost-effective in vehicles smaller than the Classic model Prius to the new larger Highlander-Hybrid with front, rear, and AWD configurations. That's wider spanning IMA, BAS, and Two-Mode. Ford is the only design with similar potential.

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Tow capacity for HSD can be increased easily. Just put bigger MGR (third electric motor powering the rear wheels as seen in AWD highlander hybird / RX400h).

 

When I started looking at hybrids, it was going to be either the Honda Civic or the Prius. The big deal breaker for me was that the seats couldn't fold down in the Honda Civic. I didn't even bother looking at or test drving the civic. I love my prius! I'm going for a bike ride today but since I don't have a bike rack I'll just put the seats down and stuff my bike in the back, something I couldn't do if I purchased the Civic.

 

I think that the big hole in all the arguments that Prius buyers should logically have bought a substantially cheaper small conventional car and pocketed the difference in initial outlay exceeding fuel economy savings is the general carrying capacity difference. I think the Prius is much better at occasional light/medium cargo hauling, and even everyday passenger hauling, compared to the cheaper alternatives touted.

True, just as many pickup and SUV drivers don't use their extra capabilities, and should logically have bought a lesser vehicle, I'm sure some of us don't use the extra capability enough for economic justification, but the extra does exist--dramatically in some cases.

I drive an Audi A4--my wife is the Prius driver. But I swap with her if I want to carry big loudspeakers somewhere, or other bigger cargo options.

 

Actually, technology tends to improve over time and the later vehicles tend to have the more advanced features. As a suggestion, look through the Wiki entries and you should be able to make a list of technical differences.

Bob Wilson

 

I don't know much about Hybrids, but I am a proud owner. The small information that I know is that the Ford Escape has 'borrowed' Toyota Hybrid technology (I may be wrong).

 

The claim was that Ford engineers worked on their system independently not knowing Prius was released back in 1997 (7 years before Escape Hybrid was launched in 2004). Somehow, somewhere during the development, Ford found out that Toyota had already patented it and decided to license the gen 1 technology from Toyota and released the product.

Toyota released the 2004 Prius with next gen technology in Sept 2003.

 

Actually I believe they are cross-licensed. That in itself proves nothing about either copying the other. Often early patents in a field are so broad that a completely independent development would be vary likely to conflict.

The whole system has a lot more to do with business interests than with invention. Been there, done that, got a few tee shirts and a plaque.

 

:rapture:Lexus RX 400h's do have a electric A/C just like the Prius.