Posts by Anne van der Bom

It's a hype but not a lie

Dear Anonymous Coward,

According to the specs the Highlander consumes marginally less fuel on the highway, supporting your view. But in city traffic, consumption is significantly lower. Because city traffic is unavoidable in every-day car use, the Highlander hybrid will save fuel.

You doubt whether the extra pollution (battery & electric systems) and/or cost is worth the gas saving. Good point, but it is another debate. You do not help your cause by distorting the facts.

You call in the higher powers of 'the laws of physics' to prove your point, while you should be looking at the 'laws of gasoline engines', which dictate that efficiency varies depending on load en speed. Reminds me a bit of August Magnan who once used 'the laws of physics' to prove that bumblebees couldn't fly.

Not quite so bad as you think

@Peter Jonston

You may be right about the 80% environmental damage being done in production. I know that producing a car costs about half as much energy as it will use during its life time. So production accounts for about 30% of total energy. But environmental damage is of course more than energy consumption. During its lifetime a Prius will save about 4000 l of gasoline (200.000 km * 2 l/100 km) over a normal car of equal size. Ask yourself this question: what is worse for the environment: producing a battery or burning 4000 l of gasoline?

The low fuel consumption is not the only green aspect of the Prius, Toyota also took measures to make it more recyclable.

You state: "can you see people looking to buy an 8 year old Prius with that expense round the corner". Your (wrong) assumption is: guarantee = lifetime. Think about that. How long is the guarantee on an average car, 2 years? By your logic that would mean that the life expectancy of an average car is 2 years! People buy second hand cars all the time, even if it is sold without any guarantee at all. I bet the Prius will be no exception.

Battery life depends on how you use it. Deep discharges are most damaging to the life expectancy of a NiMh battery. That's why the Prius is programmed to avoid just that. And most consumer gagdets are not. Do not automatically conclude that because consumer gadgets often suffer failing batteries, the Prius will too.

This is why the Prius is green

Andy,

I own a Prius, and with careful driving I manage about 4.7 l/ 100 km on average (summer & winter). This is better than a 1.2 l Corsa. Don't forget that the Prius offers more room and comfort than a Corsa. A Corsa-sized Prius would defnitely be more economical. Be careful with comparisons!

You state that the Corsa would be more geen because it has a 1.2 l engine versus a 1.5 l in the Prius. The Prius has an Atkinson cycle engine, which has a higher efficiency, but lower specific power. It delivers 57 kW, less than the 59 kW the 1.2 l engine in the Corsa puts out. Do not assess the 'greenness' of a car by taking only engine displacement in consideration.

A serial hybrid is not a good idea because the losses in the drivetrain are too high. The Prius tries to drive the wheels directly from the combustion engine as much as possible. In a serial hybrid all power from the engine would have to be converted from motion to electricity and back to motion to drive the wheels. I estimate that the real world efficiency of a serial hybrid drive train would be 80% at best, using current technology.