Dear Labrat,

The petrol engine charges the batteries while driving.

So why bother with the approx 200kg of batteries if you are going to use the engine.

Regenerative braking to charge the batteries.

How much energy is generated in 100ft of braking from 50mph. Bugger all i would suggest.

I still see no advantage in a hybrid compared to a fuel efficient modern shopping trolley car.

2 days a week i do 80km so with a range of 60km i would have to push the damned thing 20km home.

Unless i switch on the petrol engine.

ps the new HOLDEN HSV GTS with the new 6.2L engine looks fun. Or even the new Ford FPV turbo 6 which is much more fuel efficient for similar power.

regards David

Well, I have been known to make round trips around the 760 mile mark (around 1200km for those of you who like to say they're doing 160km/h rather than 100mph to massage their ego!), and I can do that on one tank with a heavily loaded car. Admittedly, for my routine rural/semi-rural driving I only get around 600miles to a tank, but I don't really imagine that a Hybrid would perform well at all under those kind of driving conditions. Not to mention that I've had low rolling resistance tires before, and they are dangerous in the road conditions we get round here in Winter!

I don't doubt that hybrids have a future for urban dwellers who are doing a lot of stop/start, and low speeds. I just think there are better options at the moment. The A2 I mentioned in automatic form put in "eco" mode does much that a hybrid does, stops and starts it's engine, coasts when you lift your foot off the gas etc, yet is a lot lighter due to the lack of huge batteries and its aluminium construction and gets far better millage than a Prius. For me Hybrid drive is completely meaningless, it is rare for me to be driving slowly enough or stopping and starting enough to see any benefit from carrying the extra battery weight.

Hmm, the Prius certainly polarises opinion. I personally think it has some good points and some bad, but on the whole it is not really as good as it’s made out to be. The low CO2 figure does not seem to reflect the average fuel economy this car seems to achieve. At the 45-50mpg average generally seen by the car we have here, it would put it equivalent to the Skoda Octavia 2.0tdi (145g/km). The reason the CO2 is so low? Hmm, I wonder if you could get the car to recognise it is on the (totally unrealistic) emissions drivecycle and get the electric motor to help more than normal………?
Yes regenerative braking does help so you can store the energy to use later (it also aids acceleration under high demand in the Prius’s case), yes the low resistance tyres and low aerodynamic drag help to reduce consumption (all good things) but travelling up the motorway at 70mph will not be using the batteries so you are stuck with having to lug the batteries and motor around with consequent weight penalty – not good for economy.
In the city under electric power it has a finite range. Once the batteries are depleted he engine is required to charge the batteries AND power the car, increasing fuel consumption more than required on petrol alone.
The stop-start technology does make sense, why have your engine running when you don’t need it?
BMW’s Intelligent Dynamics are inspired in their application by optimising aerodynamics and alternator charging (as well as stop start) to good effect all without the weight penalty of motors and batteries.
Diesel engines are good for economy as they are more thermally efficient than petrol engines, but their particulate and Nox emission are not good. But hey, it’s CO2 we get taxed on not total pollution. At least these can be overcome with particulate filters (generally unreliable and not suited to town driving) and urea injection (Mercedes Bluetec).
I think Toyota has got a lot more “Green” publicity than it deserves. How much energy is used to make these batteries? What happens to them when the car is scrapped? How are the batteries charged when the car comes off the production line? Coal power station? Petrol engine?
My ha’penny’s worth…

I wonder what a Prius would be like with a Chevy V8 427 block in it?

Heavier?

No less ugly but several factors more dangerous! Not necessarily heavier without all those batteries.

And why not go with a decent modern V8, rather than a massive monstrosity originally designed in the 1960s to pull trucks? I mean come on, even in its most recent incarnation it only produced 430bhp, you can get that from a modern engine almost 1/4 the size!

A female relative has a Prius - but it replaced an earlier one (bought 3 years before) which she drove into a lake in last year's floods, writing it off! The Toyota people couldn't fix it, apparently. I'd avoid.

Having said that, it really is about time the ultra-conservative motoring industry looked at ways of producing better cars which don't need petrol. Hopeless lot.

quote:

Originally posted by djftw:
And why not go with a decent modern V8, rather than a massive monstrosity originally designed in the 1960s to pull trucks? I mean come on, even in its most recent incarnation it only produced 430bhp, you can get that from a modern engine almost 1/4 the size!

It originated from a 1945 design to be pedantic, but I think you are missing the point, which was irony. It sounds nice and will give 8 mpg on a run. The ultimate finger to the environmentalists.

To be even more pedantic you're thinking of the 348, the 427 was first produced in 1963. However, I am fully supportive of giving the finger to environmentalist!

quote:

I mean come on, even in its most recent incarnation it only produced 430bhp, you can get that from a modern engine almost 1/4 the size!

Try getting a 2.0 l to produce 600+ ft/lbs of torque though.

quote:

Originally posted by djftw:
To be even more pedantic you're thinking of the 348, the 427 was first produced in 1963.

Smartarse

quote:

Try getting a 2.0 l to produce 600+ ft/lbs of torque though.

True, though not exactly neccesary unless you have a truck! Not to mention the extra weight of the engine, gearbox, clutch etc. needed to handle all that torque!

I've got one and would recommend it Roomy,reliable and economical for such a big car. Also low depreciation and > 500 miles before you need to fill up.Best thing is engine stops in a traffic jam or when travelling at slow speeds -but can be quite nippy too.

I've just looked at a Fiat Panda diesel. 50 mpg urban, 75 mpg extra urban, 60 mpg overall. 113 co2, so £35/year road tax. Four seats.
I could live with that. I really do see these clever diesels being a more sensible option than any hybrid, and I see those figures being pretty poor compared to what we will see in the coming years. It'll probably be a manufacturers race to 100 mpg, and then 150.

Dear Merrydance,

The stop start engine is not new.

I think VW had this on an economy model back in late 70's early 80's.

There ia a new variation on the theme coming thanks to the wonders of computers and fuel injection.

It does need the starter motor which is the failing of currnet systems (starter motor).

When cylinder is on compression stroke a reduced fuel load is injected in to that cylinder this reduced fuel causes the engine to rotate backwards causing the cylinder on the ignition stroke to compress then fuel is injected and fired and the engine rotates in the correct direction as if nothing had happened. Simple but it has taken enormous efforts by the computers and injectors to achieve.

The yanks since the 80's have used cylinder shut down turning a V8 into an in line 4 as one bank is switched off. The latest generation of General Motors LS3 V8's have this feature.

So there are alternatives to dragging around electric motors and batteries which contribute little but MASS to the car.

regards David

quote:

When cylinder is on compression stroke a reduced fuel load is injected in to that cylinder this reduced fuel causes the engine to rotate backwards causing the cylinder on the ignition stroke to compress then fuel is injected and fired and the engine rotates in the correct direction as if nothing had happened. Simple but it has taken enormous efforts by the computers and injectors to achieve.

Thats very clever - i like that sort of engineering