diesel/electric hybrid released 74 mpg euro cycle

[Danncomm]

Just read the news release World’s first diesel-electric hybrid: Peugeot 3008 HYbrid 4

I'm sure it will be a Europe only release.

[RobertSmalls]

I believe this is the first hybrid from a French automaker. I can't find any info on whether they developed the technology in house or not.

It looks like it beats the Prius, 3.8L/100km to 3.9L/100km. That's actually a win for the Prius, since diesel is ~12% denser.

[Daox]

Its hard to tell, but is the 3008 a larger vehicle? Seems like a 2.0L diesel is already a large engine.

[Piwoslaw]

Originally Posted by Daox

Its hard to tell, but is the 3008 a larger vehicle? Seems like a 2.0L diesel is already a large engine.

The weight of the (non-hybrid) 2.0 liter diesel is 1600 kg. The hybrid version should be ~150-200 kg heavier.

[Daox]

So, its relatively Corolla (the current 2010) sized. Seems like a very large engine for that size vehicle. The gas engined Corolla here is only 1.8L with 132hp. The hybrid Peugeot is 163hp just on diesel alone.

[euromodder]

The 2.0L HDI is a very common engine in Europe.

But I fail to see the point of this car.
It's pretty heavy to start with without the hybrid system, then they throw in a relatively big diesel engine.

99g/km is or surely must be achievable without a heavy hybrid system.

It'd have been nice to see the very efficient 1.4 or 1.6 HDi engines being put in diesel-hybrids.

[NeilBlanchard]

This is an odd take on a parallel hybrid -- the GM Precept has it the right way 'round, I think. The Peugeot has a full-sized engine, capable of being the only power source, and the required big, heavy, and expensive transmission. The electric drive train is in the back, where it has very limited regenerative braking, and if it is used by itself for low speeds, then having it in the back is odd. It might be used to provide 4-wheel drive, but it is over-matched by the diesel. And, powersliding/oversteer which is the only good thing about rear wheel drive is not possible.

So, it seems like an odd duck, really.

[Piwoslaw]

Originally Posted by NeilBlanchard

So, it seems like an odd duck, really.

Because the 3008 is an odd duck. It's a so-called crossover, which means that it is supposed to combine features of an SUV with a station wagon. The outcome is such that it is neither, but weights (and costs) more than if it was only one of those...

Originally Posted by euromodder

But I fail to see the point of this car.
It's pretty heavy to start with without the hybrid system, then they throw in a relatively big diesel engine.

Because heavy cars require big engines. The previous generation of 2.0HDi engines had 90 to 110 hp, the 2.0HDi from the (non-hybrid) 3008 is 150 hp (manual) or 163 hp (automatic).

It's too bad that Peugeot/Citroën keeps investing in its 2.0 HDi engine instead of the 1.4, or producing a 1.2 liter turbodiesel. The cars keep getting heavier and more powerful. I'd love to see the aerodynamic 3-door C4 lose some weight and get a 1.2 diesel hybrid system. Instead, the new generation of C4 will be heavier, more luxurious, and only produced as a 5-door.

[RobertSmalls]

So it's an expensive, luxury mini-SUV/tall station wagon that weighs almost two tons and gets mileage similar to a Prius. They still should have reduced the size of the diesel engine to account for the available torque from the electric motor. Admittedly, this is less effective with diesels than with gas.

When the final numbers are out, it will be interesting to compare price, mpg, and weight between the hybrid and non-hybrid versions.

[LoveLearn]

How vehicle reviewers select vehicle-performance criteria largely determines which configurations they judge to be "best." I keep seeing comments by reviewers who seem almost exclusively driven by MPG considerations which favor configurations which only perform well when judged by that MPG criteria. While that's understandable, I can see merits from developing hybrid systems where the engine's usual operating mode stays close to its lowest Brake Specific Fuel Consumption region, yet retains a robust power reserve available in a higher BSFC region when the driver feels applying more power justifies that higher BSFC cost. Safe passing on 2-lane roads, quicker on-ramp acceleration to more-safely merge with multi-lane traffic and other circumstances argue against entrusting your family's welfare to minimalist engines which, even in an emergency, can develop little more power than is required to sustain steady-state cruising speeds.

Having studied hundreds of BSFC maps, all I've seen generate their lowest (most efficient) values at high throttle settings near their torque peaks. Maximum horsepower in those torque-peak regions where engines develop their best horsepower-hours-per-gallon are greatly reduced compared to their peak horsepower which occurs at higher rpm. I like having a substantial horsepower reserve available even though it requires increasing engine rpm. Through careful planning, we can drive so that's rarely needed. But when (not if) one of those "Oh MY God" moments occurs due to some idiot driver's unexpected behavior, and you need more power right now, I'd be willing to lower my overall fill-up-to-fill-up mpg to keep my family, myself and my property safer. If you have no significant power reserve when you really need it, that long-term maximum mpg at any cost strategy may cost those you love a lot of grief. If you'd have asked me about that 50 years ago, when I had less life experience with idiots on roads, I might also have assigned almost zero value to reserve power for unexpected driving circumstances.

I expect any really well designed diesel-driven electric configuration will be able to reduce engine speed to its least fuel-consumption rpm for the instantly-required throttle-controlled road-horsepower. I expect that diesel will be wonderfully reliable because it will be so ideally loaded, running almost all of the time at low rpms and high throttle settings. Mean time between overhauls for 60-cycle 4-pole direct-drive diesel generator engines which run at 1800 rpm is MUCH longer than mechanical-transmission loaded automotive engines. In Europe, 50-cycle 4-poll direct-drive diesel genset engines run at 1500 rpm also with exceptionally long service lives.

Is sizing a diesel engine so it is most durable "over-sizing?" According to some of this forum's participant's judgment criteria, that would surely be "over-sizing." But that's not my perspective. I like having incredibly durable drive systems with robust reserve power-delivery capacity when I feel it's needed. If that's available with very little extra MPG cost compared to minimalist-sized power systems which can't comfortably cruise coast-to-coast in their torque-peak region, I'd greatly prefer the larger engine pulling the load at lower rpm where it may last 20,000 hours between overhauls.

While I see substantial difficulties in obtaining competitive efficiency from a diesel-electric system, I expect that with equal development effort, it would be more durable than most direct-drive configurations. Diesel-electric rail equipment may not be the most efficient, but it would be hard to fault their durability.

I'm not ready to dismiss diesel-electric configuration cars that don't have a minimalist-sized engines. Without examining any car's on-road BSFC engine loading, I don't see how anyone could intelligently do that.
Just my opinion.
John