Edmunds.com | Inside Line | Auto Observer Your Account | Help | Directory
You are here:
![[F]](http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com/media/townhall/webxicons/site.gif){kind=small}
Forums
Hybrid Vehicles Hybrid Vehicles - Archived Discussions Hybrid Diesels? 
395 messages, Last post on Aug 29, 2007 at 7:27 AM
You are in the Hybrid Vehicles - Archived Discussions Forum. Your Host is pf_flyer
This discussion is ARCHIVED. To reactivate the discussion, post a request in the Lost? Ask the Hybrids Host for directions! discussion.
|
This was taken from http://www.gm.com/company/gmability/adv_tech/300_hybrids/fact_hybrid_bus.html "engine and a hybrid transmission consisting of two 100 kW motors and a 600-volt, nickel metal hydride battery pack. The engine is coupled to an electronically variable transmission that provides an infinite range of gear ratios to drive the wheels." After some digging I found that Cummins engines in the 250-280Hp are the prime movers for the above. And a max service speed of 65mph was quoted. First I have to say no hybrid bus can be that efficient that still needs to install a Cummins 280Hp diesel that is probably running full time in summer to power a 6 ton A/C for driver comfort. Second when route averages are often below 10 mph in urban areas having a vehicle capable of 65 mph is somewhat overspec'd for the job, wouldn't you say ? GM Allison can't take all the blame. After all, it's not an electrical engineer's signature that appears on their customer order form. Recently I came across a study by two researchers in Britain which found the same insanity exists there. They discovered that diesel operators received a fuel subsidy whereas operators of electric surface transport and light rail transit did not. In fact they received no government credits at all although it was the stated aim of the government to reduce vehicle pollution in cities ! Making phone calls to manufacturers revealed that with a replacement of only 3000 buses a year in Britain this was not a big enough market for them to get seriously interested. Hence the miniscule progress in the last 25 years. Bus systems were not properly specified for the routes and this incurred much greater expense than needed. On a personal note I still remember back in 1965 a driver remarking that he was told that his vehicle, a brand new 85 seater doubledecker Leland 'Atlantean', was capable of 100mph although we were both aware none of these vehicles would be permitted to exceed 40mph 'in service'. The researchers concluded that amongst other things that buses limited to 90Kw powerplants in order to be eligible for goverment funding would promote a less cavalier approach to vehicle design. Levelling of the playing field by eliminating fuel subsidies would also ensure 'sound' decisions by local authorities for encouraging the adoption of greener technology. T2 |
|
|
Replying to: toyolla2 (Nov 25, 2006 9:05 pm) As for being overspeced. No theses Hybrid buses also need to travel on expressways at 55 MPH or 65 MPH depending what types of service is being required. Also Mass Transit systems are required in Emergencies to provide support. And a forty foot transit bus can safely move 60+ people at one time without being restricted to an external electrical power source which fail from time to time.
|
|
|
Check this pup: The Sandstorm, from the Hyundai Kia America Design Center, steers close to the familiar look of the classic dune buggy. Eco points for this "biodiesel electric plug-in hybrid" would come from features including solar-powered cooling, detachable recycling bins and recyclable polyethylene terephthalate (PETE) panels, so that riders can quickly change the color scheme to suit the mood. 
|
|
| Yea, I liked the Sandstorm too. Started up a discussion about the design contest http://townhall-talk.edmunds.com/WebX/.f0fdf17 | |
|
Replying to: goodcrd (Nov 27, 2006 10:12 am) good post, whereas I was calling to question incompetent design supporting unrealistic specifications you've taken it to a whole new level by tearing into the Cummins engine itself. I've always thought of Cummins as a top tier supplier but according to you they have a head gasket problem at 120,000 miles. And if Cummins knows about this then they don't seem to be doing anything about it on account of the fact that they are less expensive than the more robust Detroit diesels ? Hmm, I wonder if Cummins is aware that Toyota has bought into ISUZU to gain ready access to Isuzu's commercial market ? Cummins needs to get more serious about its defects or Toyota will do to them what it has done to GM. I am not a romantic towards trams and trolleybuses but it is a simple fact that the costs asociated with railbed and power distribution systems were subsumed by those operators whereas the roadbed system being part of the 'commonwealth' was provided almost free to operators of diesel buses. If buses had to pay a more justifiable fee for use of the road bed commensurate with their usage then electric transport might still be around. The Capital costs for Rail are much higher. 300,000 per bus and 1,000,000+ per light rail vehicle. And I bet the average speed for the LRT is also three times higher and more deterministic, not sure thats a valid comparison. In case you would bring up rail track costs I might remind you that the payback for libraries and opera houses is almost non existent as well. Should we not have them too ? As for being overspeced. No these Hybrid buses also need to travel on expressways at 55 MPH or 65 MPH depending what types of service is being required. . I was not suggesting that transit authorities limit themselves with lower power vehicles for their whole fleet but only for the 90% of the routes that do. Same argument as between hybrid electric cars and off road yacht-towing SUVs. Also Mass Transit systems are required in Emergencies to provide support. And a forty foot transit bus can safely move 60+ people at one time without being restricted to an external electrical power source which fail from time to time I would like to agree with you on this one but recent experiences with New Orleans showed that emergency services even in peace time by the most advanced nation on the planet are not competent to do this. Anyway I would see this as an unreasonable requirement of mass transport that is seeking to be as nonpolluting as possible. I might ask what emergency need was fulfilled in the past by having this capability ? This sounds more like a 'want' than a reasonable 'need' to me. reliance on an external electrical power source which fail from time to time OK, let's get back to diesel hybrids and avoid that problem! T2
|
|
|
Replying to: toyolla2 (Nov 28, 2006 6:31 pm) |
|
|
Analyze this http://www.ornl.gov/~webworks/cppr/y2001/rpt/121813.pdf I guess a persons views on reverse engineering depends on who's doing it. ! 
|
|
|
Replying to: toyolla2 (Nov 30, 2006 8:02 am)
|
|
|
|
| I checked the patent literature and found a 1979 U.S. patent for using a thermoelectric device to convert some of a hybrid vehicle exhaust heat to electricity. I ran a Google search and found that only the Toyota Estima minivan uses this or a similar technology. If 1/3 of the heat generated by combustion is ordinarily lost as heat, and if 1/5 of this could be converted to electricity (and sent to the hybrid storage batteries), this would give us an increase of overall efficiency of 1/3 * 1/5 = 1/15 = 6.66%. This should, therfore, be economically worthwhile. So: does anyone else on this list have more information of the appropriate thermoelectric device and associated wiring to use? | |
|
Replying to: goodcrd (Nov 30, 2006 10:32 am) Pre-WWII trucks? uh.. V8's have been in 'T' vehicles since 1998. They and the transmissions are doing fine thanks.
|
|
You are here:
Forums
Hybrid Vehicles Hybrid Vehicles - Archived Discussions Hybrid Diesels?
