Peugeot 3008 HYbrid4

Well at least it would be very economical,

It's so hideous that you want to get near enough to it to actually drive it.

Re: Struggling to see the point?

I think the point is that it supposedly gets around 30 more miles per gallon that standard. Only time will tell if this is correct.

Re: Struggling to see the point?

Because an engine can be set to its most efficient RPM. Perhaps 2000 rpm is peak torque for this engine and runs most efficiently. Keeping the battery around 80% charged at the most efficient fuel setting would mean the least amount of energy wasted. I.e. no "idle" technically as your battery would deplete whilst driving and charge whilst idle/below the charge/usage curve.

Obviously you would need to factor in efficiency but in theory it is a sound system:

1) idle charges battery.

2) set off uses most "fuel" and ratios as its not very mechanically efficient so use the battery.

3) cruise uses engine and charges battery at a more efficient engine setting.

4) regen braking (balance to the rear though?)

5) back to 1

I like this idea. You have the CHOICE to use as a normal FWD diesel if situation permits. If you are pootling around town then use the battery. It would be interesting to see a weeks worth of normal driving miles vs fuel put in vs a "normal" without using the electric mode.

Re: Struggling to see the point?

There are gains to bad with regen braking - this is one definite and obvious place to gain back some fuel economy, instead of simply wasting it all to friction brakes. Although I admit just tossing out all that weight would save you money and probably help just as much too..

Re: Struggling to see the point?

I think the downvotes for a sensible question seems harsh, but yes it's a counterintuitively more efficient means of harnessing an internal combustion engine's power. I believe an ICE is limited to about 40% efficiency as a theoretical maximum. In a standard car, it's real world efficiency is around 20%, less in many occasions.

As Danny points out above, you can keep the engine set to its most efficient speed regardless of where the drivetrain is. Think of it as an infinite ratio gearbox. In this case, with a diesel, it would be a particular improvement given a diesel delivers all its power at the top end of each gear.

A similar setup (forget which, but was a series hybrid) was reviewed on Top Gear a couple of weeks ago. James May tried to explain it to that blithering idiot Clarkson who as expected cut him off stating it was boring nonsense..

Re: Struggling to see the point?

Yes, it's a lossy process but hybrids benefit in a few ways:

- You have the opportunity to regen, capture and re-use some of the otherwise discarded energy. (The shift to lithium will improve regen)

- You can stop the engine under idle rpm. Normal cars can use DFCO when you don't need the engine and revs are high enough to prevent stalling, but with a hybrid you can cut the engine and use electric for small loads, as that can still be more efficient despite the lossy process. Which, in part leads us to ...

- You can keep the engine running in an efficient rpm band, either using spare power to charge the battery or using assist to supplement it. Using assist a lot is bad, but in average conditions you benefit overall.

- In a full parallel hybrid setup you can modify the engine cycle for efficiency over torque and use the assist to provide the additional torque when you need it. That's of more benefit with petrol hybrids. Again, you don't want to be working the assist a lot, but in many driving conditions you really don't need that much torque.

- You can shift more auxiliary systems to electric: as well as having fully-electric A/C the Gen 3 Prius eliminated all belts.

Fully electrically driven cars will be great, although the relative efficiency depends significantly on the efficiency of the grid (but personally I love the idea of finally not really caring what happens in the Middle East), but the problem with electric drive is that you need a large battery and motor to deliver enough power to drive the car at all normal speeds. Batteries don't just have capacity limits, they have charge and discharge limits, which depends on the chemistry.

Re: Struggling to see the point?

As other more knowledgeable folks have pointed out, this gives you a more efficient use of the diesel. Something similar has been used for locomotives since the 1930s.

Which makes me wonder - any chance of a diesel hydraulic car?

Re: Struggling to see the point?

A battery powered car that can do 80mph on a motorway all day even with a small engine to charge it - is a way off. The battery on this would only provide 1.5HP for an hour.

This is an economical family diesel where you don't need to run the engine in traffic and at low speed around town.

KERS only makes sense if you aren't mostly slowed by wind resistance, as in a car. It does work if you need massive fast braking (as in F1) or you weigh a lot and need massive slow breaking (as in a Truck/bus) and you brake/accelerate a lot.

Re: Complicated electrics and French?

God yes. The building where I work was a PPI job with a French company. There's been a power cut almost every other weekend for the last two years fixing problems, and in the last 6 years, we've lost 20 working weekdays to dodgy power supply components, all of which were French and needed couriering from overseas.

Re: What took them so long.

Feel free to take up a job in Vehicle Development if you feel the pace is a bit slow. There's a little bit more to it than "I've had an idea! Lets launch it"".

Actually thinking about it, considering your idea for a hybrid 2 cylinder diesel supermini, I'd rather you didn't...

Re: Metric would be welcomed.

Why? UK site, UK measurements. If you want things in metric go read a local review instead.

Maths to the rescue!

Khaptain, one doesn’t need to speak Imperial to receive a translation to SI. Just grab a slide rule and follow this simple formula:

282.48 ÷ miles_per_Imperial_gallon = litres_per_100_km

Please note that we in the States don’t use Imperial measurements either — we continue to use Queen Anne’s wine gallon and King William III’s bushel, in preference to their respective Imperial substitutes.

Re: Metric would be welcomed.

I would prefer km per litre.

Re: Nice idea (shame about the car!)

With a series hybrid yes you need a larger electric motor, but you can get away with a smaller higher efficiency engine/generator.

Most cars when cruising (i.e. motorway) don't use that much power IRO 10-15bhp depending on the car.

The size of the battery pack only determines how long it can run on electric only.

4WD is pointless the majority of the time for most road users, other than the exceptions you raised, which in the UK aren't that common unless you live on a farm.

Re: the batmobile beats this

To my knowledge turbines give poorer fuel economy than IC Engines (at least for the size you can fit in a car comfortably).

Where turbines shine is in power to weight ratio, which is important for aircraft, and they improve in efficiency the larger they are (hence why they try to stick a few big engines on aircraft, rather than many little ones).

AFAIK that is the primary reason they have not been used in cars so far. Not to mention noise limits in urban areas, really hot exhaust, and probably a few other niggles I've not thought of at the moment.

Re: The worry....

Manufacturers will love it then, cars obsolete in 3-5years = more sales.

Re: The worry....

I've had a Prius for almost 7 years now and if there is any degradation in the battery pack, it is not apparent. A cheaper alternative to battery pack replacement is refurbishment and a number of companies (mostly in the USA) offer such services, mostly for the older 1st generation hybrids.