A toyota diesel? That's also a hybrid? And a subcompact? This is the greatest idea I have ever heard of!

Imagine a Prius that already gets 45mpg rw(real world).

Now make considerably smaller and it gets 50 mpg easily.

Now make it a diesel and it gets 60 mpg minimum! Honda insight numbers!

From there there is always the plug in hybrid option that bumps fuel economy to 120 mpg and or Biodiesel which will be widely available by the time this comes out!

Except for an electric car there would be no more eco-friendly vehicle, and the average American would save $1550 a year on fuel!

(Average American drives 30,000 miles, assuming a 30 mpg car = 1,000 gallons at $2.3 for regular = $2300. 30,000/120 = 250*$3.00 for Biodiesel = $750.)

Now as to price, i imagine a sub compact hybrid will be super popular and easily fetch %17.5-20K.

Throw in the diesel premium and the price comes to $22.5-$25k.

Plug in costs no more than $5K by this time.

Would I pay $30K for a Toyota Yaris sized diesel hybrid?

YES! HERE"S WHY!

A loaded Yaris comes to $17500, and a diesel hybrid will most likely also be loaded.

Thus the price difference is $12,500.

At $1550 annual savings this pays for itself in just over 8 years!

Of course fuel prices can be expected to rise even more so lets look at gas at $3,4 and $5. (assuming that biodiesel is $1 more than gas at all times.)

$3/gallon $4/gallon Biodiesel

Cost for Yaris@ 30 mpg(1k gallons) = $3,000
Cost for SCHD @ 120 mpg(sub-compact hybrid diesel)
= $1,000

Savings= $2,000/year requires 6.25 years to break even.

$4/gallon $5/gallon biodiesel

Yaris = $4,000
SCHD =$1250
Savings = $2750
Break even time= 4.55 years

$5/gallon $6/gallon biodiesel

Yaris = $5,000
SCHD = $1,500
Savings- $3500
Break even time= 3.57 years!

So you see, even making a purely economic decision with no carbon tax, such a sub-compact hybrid diesel running on B-100 makes sense!

Throw in the benefits to national security and the environment and you have a car that will sell like hotcakes!

Toyota is truely an innovation leader! No wonder they will overtake GM and Ford!

By 2015 they might even beat GM in the US, if they keep offering such mind-boggling vehicles!

Diesel engines are heavy and expensive, relative to rated power. Same for electric drivetrains. A diesel hybrid makes sense for HDVs such as city buses, especially wrt emissions.

Achieving reasonable TCO with a mild - let alone a full - diesel hybrid in the cutthroat subcompact market would require Isuzu/Toyota to pretty much pull a rabbit out of their collective hat. Opel developed an Astra-based diesel hybrid concept a couple of years ago and Citroen PSA keep tinkering as well. Bottom line: way too expensive.

Perhaps a 1.2L/45kW three-cylinder design with a fixed geometry turbocharger might do, especially if a 15kW electric machine were integrated directly into the crankcase. An unbalanced rotor would do double duty as compensation shaft for the first order free moments. The battery would go in the back as usual for weight distribution and safety. The spare tire, if any, would have to be as small and lightweight as possible. Transmission options could be limited to a six-speed manual and an automated step-by-step design, for weight and cost reasons. The top gear should be sized for economical freeway cruising, with top speed available in fifth.

Even so, I expect diesel hybrids would find few buyers unless crude oil prices went through the roof. This is entirely possible if Iran or North Korea become acute problems or, if the civil war in Iraq spills over its borders. As the Big Three have found to their cost, oil prices can and do gyrate wildly. In that sense, it may be a wise move on the part of Isuzu/Toyota to invest in a contingency plan.

For the US market, diesel HCCI combustion technology will probably not suffice to meet Tier 2 Bin 5 emissions. The additional cost of NOx aftertreatment plus a DPF could easily render any diesel hybrid concept DOA. Consumer sentiment in the manufacturers' home market in Japan is also hostile to diesels, though without any oil of its own, that country must be prepared to adapt.

Europe and much of Asia are a different matter, but initial cost is a major issue there too. The rest of the world accounts for just a small share of the global market.

"Diesel engines are heavy and expensive, relative to rated power."

What planet are you on?

The Yaris 1.4 D4-d engine weighs approx 120kg, with 90bhp and more importantly 140lb/ft of torque (That's 2.5 litre petrol territory)

http://www.autoexpress.co.uk/carreviews/roadtests/24790/specs/toyota_yaris.html

In Europe where we actually have to pay for fuel, the diesel pays for itself in a year or two.

I think FedEx already utilizes many diesel-hybrid delivery trucks in the US and they save a lot of money.

I'd love a diesel subcompact or compact. Right now there is the Golf TDI and umm... Well a diesel hybrid with the 2010 emissions standards is a great vehicle. With WVO or SVO kits (Fribrid and Greasecar are 2) and rendering companies now converting WVO to Biodiesel cars like this are great. Diesels now produce 1ooHP/Liter BMW and Alpine do it. They spin to 6000RPM forget 4000RPM and with sequential turbos have great throttle response. Some diesels in the high performance arena have around 200 pounds feet of torque per liter. This is with the super clean and now quiet diesel engine reality. With the advent of aluminum blocks these engines are a lot lighter than before. Lets not forget a diesel has now won the 12 hours of Seabring and backed it up with the 24 hours of Le Mans. All this with green miserly intent.

Wait, I thought Toyota said NO to diesel/electric hybrids just a few weeks ago? Am I imagining things?

some basic specs for the toyota diesel dyna hybrid:
electric motor output: 36 kW (43 hp)
battery voltage: 288 V (Ni-MH)
diesel engine displacement: 4 L
max output: 100 kW @ 3000 rpm (134 hp)
max torque: 353 N-m @ 1600 rpm (260 lb-ft)

comparatively, the prius has a motor w/output 50 kW (67 hp), a battery of 201 V, and a gas engine with 57 kW (76 hp) with torque 111 N-m (82 lb-ft).

Nij -

the 1.5L naturally aspirated gasoline engine on the Yaris gets 106hp. An Opel 1.8l model weighs 120kg and delivers 136hp/175Nm. So whichever way you look at it, diesels are in fact more expensive and heavier. Your point about how long it takes before the diesel comes out ahead is well taken. But we're talking about diesel *hybrids* in this thread, and those would take much longer to amortize.

Assuming for a minute that the clean diesel/hybrid is prohibitively expensive for this vehicle class, why not a flex fueled or even ethanol optimized hybrid subcompact? Speaking of which, is the flex fueled hybrid Escape project still out there or did it die quietly? It seems to me that ethanol becomes a much more viable fuel source at , say, 50+ mpg versus sub 20.

anyone who lives in a city or has waited at a stoplight next to a bus or semi knows that there is more to being green than CO2 and mpg.

there is only one model of diesel sold in the US today as a 2007 model year car because NOx and particulate matter are important. not only b/c black clouds coming out of school busses looks nasty, but because they are important contributors to lung cancer and acid rain. these problems can surely be solved in an economic manner, but they haven't yet.

additionally, playing the mpg game becomes dumb at some point. doubling the mpg from 50 to 100 sounds impressive, sure, but (assuming $2/gal 15,000 mi/yr) the cost difference is $600-$300=$300, which is less than the cost of one car payment or $.82/day aka neglible. it won't even pay for your starbucks.

whereas a change from 9 mpg to 12 mpg (only a 30% increase) in a full-size (grossly oversized for most of us) truck gives a cost savings of $3333-$2500=$833 almost three times as much. and these sorts of improvements (such as the displacement on demand technology) are much easier to find.

point being: small improvements in big engines and migration from larger to smaller vehicles are much bigger matters to be excited about than large improvements in small engines and migration from small to tiny vehicles (which, in this case, won't be legal in states for environmental reasons anyway).

There is problem with diesel hybrid cars. Gasoline engine most of the time works on partially closed throttle, which significantly diminish it efficiency. Also gasoline engine consumes a lot of fuel while idling. Diesel engine maintains its high efficiency on partial power and consumes very little fuel on idle. Now, gasoline hybrid stops engine at traffic lights and eliminates idle completely. Due to CV transmission, gasoline engine in hybrids works on low RPM and wider throttle, i.e. close to its max efficiency. Also hybrid configuration allows beneficial use of more efficient Atkinson cycle, like in Prius gasoline engine. Substitution of gasoline engine by diesel in hybrid car will yield only marginal improvement in fuel efficiency, 10% max. I agree with Rafael that for car traveling 15 000 miles a year diesel hybrid does not worth troubles. For commercial vehicles, like buses, delivery vans, or refuse collection trucks, diesel hybrid makes total sense.

Sorry George, though as an asthmatic doctor you might expect me to agree with you I think you're way off. First, when I worked in what Americans would call the ER, I never saw anyone who came in dying of *particulates* - sure, across the world toxic cocktails of smog kill people (looking back at respiratory deaths from London's "pea-souper" smogs before the advent of the Clean Air Act reduced the use of coal in domestic heating and you could certainly point to large numbers of excess deaths), but nowadays (outside smog areas - which come about for more reasons than just particulates) we are primarily looking at effects which are gradual exposure damage, possibly measured over a period of decades. If we are trying to compare particulates with CO2 then we should look at the long-term consequences of both to lives. In global terms CO2 is much, much, much, much worse than particulates and timescales which are critical now for emissions are years not decades even though worst effects may be felt across decades. To be fair the calculations will get much messier if one is trying to match CO2 emissions from a single vehicle versus estimated health consequences for diesel from one vehicle. I also suspect that a diesel motor, constantly running at close to its optimum parameters as a generator in a hybrid, rather than as a variable output direct drive motor as currently, will be much better on particulates even if it isn't so markedly more efficient as Rafael suggest. A more important issue I think is what expectation you have of your transport fleet as a nation. Think about car replacement rates (and whether these will go up or down as energy generally gets more expensive), think about fuel availability and whether bio-diesel or dodgier fuel stuffs will be more available than petroleum. Think about wider issues and I suspect you will want to have quite a lot of small diesel-hybrids in your fleet mix, robustly enough built to last 10+years out there as you can get while the costs are relatively small (though I agree the capital expense and apparent initial running costs are high and trucks are a bigger target.. but then getting more people onto pedal bikes is probably a bigger win for health and planet than anything on this blog!).

George. Light duty diesels are not causing those deaths. Trucks/buses/construction equipment are causing those deaths. CO2 is, yes IS, causing hundreds of thousands of deaths per year already.

Biodiesel is a much more viable fuel than ethanol, requires no new infrastructure, already can be made from a myriad of feed stocks, both virgin and waste. Oh yes, it also results in much lower particulate without any after treatment. Yes, a little more NOX.

Diesels mean a viable fleet of vehicles running on carbon neutral fuel. Diesels mean a fleet of vehicles that will last twice as long as a gasoline fleet. Diesels mean smaller vehicles with high torque. DIESLES MEAN LESS CO2.

The planet is roasting and you're oblivious.