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Discussion Starter #1
Taken from here:

Most interesting point is that the battery is only 1.3kWhr in the '04, which by my reckoning makes it about ~30% smaller than the battery in the '03 model. This switch probably explains the relatively inexpensive replacement price of 723 ($1,230), which is cheaper than some major services on some other models over here. This also equates to about 550 ($900) per kWhr, showing that prices for NiMH batteries are already starting to drop significantly, paving the way for much cheaper (read widespread) hybrids in the future. :wink:

Article here:

Toyota's new MkII Prius petrol/electric hybrid is much improved, says Andrew English

I had always thought of Florentines as delicious chocolate biscuits covered in nuts and mixed peel, not a breed of malevolent Italians with all the lane discipline of a badger, one hand cheerily on the horn, the other holding a copy of Corriere della Sera. But then education comes fast when you're trying to escape the rush hour in Florence.

"We have been given special permission to use this historic square to park the new Prius," said the Toyota PR. So too, it seemed, had several thousand Etruscan taxi and car drivers, pedestrians, cyclists, pretty girls on mopeds, two-stroke skateboarders, scooter riders, a juggler, assorted white-van and lorry drivers, newspaper boys, a carousel operator and several stall holders, with a couple of school parties thrown in for good measure. Exclusive access, it seems, is not a familiar concept to the Italians.

Choosing to launch a car in the narrow, congested streets of Florence might be considered rash, but perhaps not in the case of the Mark II petrol/electric hybrid Prius. No car produces less carbon dioxide greenhouse gas and few come even close to its low emission of local pollutants. It can run on silent, zero-emission electric power for two kilometres and, even when the 15-litre engine is used, it is uncannily quiet in town.

Driving this super-environmental car past the scaffolding-swaddled Duomo and wriggling past the builders' skips in the Piazza Signoria would have borne mute witness to the ravaging effects of exhaust soot and acid rain on Florentine history. Would have, that is, if the satellite navigation had worked, or the back-up maps had been intelligible. As it was, 30 German-registered Japanese cars tore around the centre of this 2nd-century city like the Mini Coopers did in Turin for The Italian Job. You could almost hear the cries of "Go! Go! Go!" as 30 Toyotas emerged from impassable alleys and raced into tiny gaps in the traffic. It took almost an hour to find our way out, by which time we'd retuned the in-car entertainment from sat-nav to Fat Lady Sings FM, having almost given up on ever hitting the open road. That would have been an enormous shame, for our early reports on the American-specification MkII Prius (Telegraph Motoring, May 3) don't do the European version justice.

Even Toyota admits that its original Prius, launched in Japan in 1997 and in the UK in 2000, hasn't been a sales hit. It was launched off a year of spectacular profits for Toyota against a failing Japanese economy, but it is unlikely that it has had a positive effect on Toyota's balance sheet since then. Introducing the Prius to a European audience at the Paris Auto Salon in October 1998, Toyota admitted that the twin-motor hybrid Prius would never make a profit. Its environmental credentials were impressive, but there was little incentive to buy, especially after a test drive revealed a stubby, cramped and desperately slow, four-door saloon that resembled nothing so much as a four-wheeled parrot fish. Total worldwide sales were only 120,000 — 4,000 in Europe and just 400 in Britain.

With the hatchback MkII, Toyota has addressed the performance and aesthetic criticisms and assured us that the new model returns at least some profits. This is creative accounting, of course, as the costs of developing this hybrid driveline have been enormous. However, within a year Toyota's Lexus brand will be using a similar system and eventually the hybrid driveline will be fitted to mainstream models.

Inside, the new Prius is larger, with more head and leg room for rear-seat passengers, although taller ones will still feel cramped. The seats are comfortable and supportive and it is easy to find a good driving position. The facia is unashamedly modern, with opaque black plastic panels reminiscent of a Bang & Olufsen stereo. Digital driving instruments are mounted low and behind a porthole-like lens, and there is a large display in the centre console that gives a clear indication of where the power is coming and going. The battery pack sits under the boot floor, which makes the storage space a bit shallow. We're also at a loss to work out why Toyota puts plastic trims on alloy wheels.

For Europeans, the new Prius has been given more positive steering and uprated springs and dampers over its American cousin, and the difference is startling. On the open roads of Chiantishire, the MkII Prius rode well over bumps and potholes, but at the same time turned into corners briskly, with limited amounts of body roll. This is an enormous improvement over both the old Prius and the American version of the new model, and there is now an eagerness and a competence about the new chassis, even though it's no sports saloon. That said, the all-round disc brakes are powerful but brutish in operation. Pressing the pedal, however lightly, results in passengers nodding like idiots and the nose plunging like a diving submarine. The steering is pleasantly weighted but stupendously artificial in feel, especially around the straight-ahead position.

The driveline uses a planetary gear-based drive system, which infinitely splits the drive between the electric motor and the four-cylinder petrol engine. Over-run braking energy and surplus engine power drive a separate electricity generator and the current is stored in a battery pack, which is large enough to drive the Prius on its own for a short while, although the engine will cut in to charge the battery when required. For the new model, Toyota has increased the operating voltage of the hybrid system from 274 to 500. This means the electric motor is smaller, lighter and more powerful than a one-litre petrol engine.

The Prius's petrol engine has been modified with an oval combustion chamber and thinner piston walls and exhaust manifolding, and power has been increased to 76bhp. The unit uses the highly efficient Atkinson cycle, which is like a conventional, four-stroke, Otto-cycle engine, but with an arrangement of cranks that link the piston to the crankshaft — it was first proposed by British engineer James Atkinson in 1887 as a means of getting round Otto's patents. Each piston can perform all four strokes through just one revolution of the crank and the strokes can be different lengths — the power stroke is longer, for instance, than the intake stroke (for a brilliant animated diagram of the Atkinson cycle — and other engine types — go to The advantage of the Atkinson cycle is that it increases thermal efficiency from about 35 per cent (as in a conventional Otto-cycle engine) to about 38 per cent. It also limits pumping losses, has low-rev fuelling requirements that suit full catalysation of exhaust emissions and it works well with Toyota's variable valve-timing system. Drawbacks include greater mechanical wear, lower power outputs and a lower crank revolution capability than a conventional engine. Toyota gets around the former by starting the engine at 1,000rpm to reduce wear, and the lower power and rev capacity actually suit the Prius, with its epicyclic transmission system.

To drive, it's exactly the same as a fully automatic car, which essentially it is, although there's a lot of confusing and tedious button-pushing to get the systems up and running at the start. The tiny gearlever is on the dashboard and you simply select Drive, press and go. The petrol engine seems a lot quieter and more refined than the previous model's, but the revs often bear little relation to what the rest of the car is doing, as it dances to the tune of the on-board computer, not your right foot. Overall performance, however, is much better than in the old Prius and the new model can more than hold its own in the company of the two-litre diesel family saloons that Toyota has targeted, especially in mid-range acceleration, where the electric motor adds a respectable overtaking punch.

The computer works out how much power you want and how it is going to supply it, with petrol engine, electric motor or both. Selecting electric operation works only if the battery has enough juice in it, as correctly charging and maintaining the 723 (1,000 euro) battery is the key to sustaining it beyond its guaranteed eight-year, 100,000-mile life. Apart from battery-life anxiety, there are some delightfully quirky aspects to Prius ownership, such as when you leave the car started (but seemingly inactive) and the engine starts itself to charge the battery before switching off again — it catches out unwary passers-by every time.

Toyota's system is the most complete (if not the most elegant) petrol/electric hybrid, but it is strangely other-worldly to drive. Perhaps this is because the system treats the engine as a donkey with no characteristics of its own, unlike Honda's hybrid, which gives priority to the petrol engine, using the electric motor only when maximum performance is needed. Toyota claims its sophisticated system extracts the last drop of efficiency from a conventional petrol engine, which sounds plausible, but when the hybrid system is used with a fuel cell, the benefits will not be so clear-cut.

That said, the Prius now performs and handles as well as it looks and it could also save you money, largely thanks to its exemptions from various road-user taxes and charges. In three years and 60,000 miles, Toyota claims the Prius will save 3,400 in fuel and company-car tax. It requires just 42 hours of servicing over 60,000 miles, it is in insurance group 7E, is estimated to keep its value at least as well as a good-quality diesel saloon and is also exempt from London's 5-a-day congestion charge.

The MkII Prius goes on sale on January 2 at prices that start at 17,495. Adding cruise control, a better sound system and fog lamps for the T4 spec costs another 800 and the top-of-the-range T Spirit, with sat-nav and Bluetooth technology controlled from the steering wheel, comes at a whisker under 20 grand. This places the Prius at the heart of the competition from some very good diesel saloons, and a lot of them are nicer to drive, bigger and achieve fuel-economy figures that are almost as good. There is also the Government's Energy Savings Trust PowerShift grant of 1,000 to consider, although the EST has run out of money until April; the Government is ambiguously claiming that it "will support the launch of the Prius".

The Prius is never going to be a major player in this market, but it no longer forces you to make unacceptable sacrifices for your environmentalism. Toyota reckons it will sell 1,600 Prius hybrids in 2004 and 2,500 the following year. That's a conservative estimate, I think, although it's ironic that any sudden leap in popularity for the Prius might jeopardise the PowerShift grant and congestion-charge exemption that will make it so popular in the first place... Doh!

Toyota Prius

Price/availability: 17,495 (T3), 18,295 (T4), 19,995 (T Spirit). EST PowerShift grant of 1,000 is available. On sale January 2.

Engine/transmission: 1,497cc, four-cylinder, high-expansion Atkinson-cycle petrol with DOHC and four valves per cylinder; 76bhp at 5,000rpm, 85lb ft of torque at 4,000rpm. 500-volt, synchronous electric motor; 67bhp from 1,200-1,540rpm, 295lb ft from 0-1,200rpm. Sealed nickel-metal hydride 65Ah, 2016-volt battery. Planetary gearbox. Front-wheel drive.

Performance: top speed 106mph, 0-62mph in 109sec, EU Urban fuel consumption 565mpg (Combined 657mpg), CO2 emissions 104g/km.

We like: Economy, practicality, styling, performance and refinement.

We don't like: Dead-feeling steering, jerky brakes, lack of engine braking, runaway engine note.

Alternatives: For congestion-charge exemption and low road and company-car tax, try an LPG conversion or Honda's 15,000 hybrid Civic IMA, a used Honda Insight hybrid at about 10,000 or a used Toyota Prius for the same amount. For amazing fuel consumption, try a Volkswagen "3-litre" Lupo or Audi's equivalent "3-litre" A2; both will achieve 100km on three litres of diesel (941mpg), but are available only as LHD models in Germany, where they cost 14,875 euros (10,300). For space, diesel economy and a five-door hatch configuration, try a Citro� C5 22 HDi VTR (17,700), Ford Mondeo 20DCi Zetec-S128 (18,050), Peugeot 406 22HDi (136) SE (17,300), Nissan Primera 22 dCi SVE (18,000) or Honda Accord 22 i-CDTi (20,000).

165 Posts
Thanks for the post, clett. However, let's note that the author misunderstood the cycle used by the Prius engine. It's not really his fault, because what Toyota calls an "Atkinson" cycle is in fact closer to a Miller cycle. Atkinson had first the idea to make the expansion stroke longer than the intake stroke to improve efficiency, but the way he implemented it was rather complex as shown in the link given in the review. Miller later achieved the same effect simply by closing the intake valves "too late", and that is how the Prius engine works.

Pleased to know that the new battery costs only about 1000 ... MUCH less than the price I was given for my "classic" battery. 8)

53 Posts
Unexpected demand

Toyota has vastly underestimated demand here in US-those estimates seem awfully low across the pond. They probably are listening to the same fools who did the market research here!!javascript:emoticon(':lol:')
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