[tsk1979]

Originally Posted by cutthecords

Also - a question. Why does diesel give more mileage than petrol? Does the fuel intrinsically have more "energy" to burn? Or is it the way diesel engines are designed?

The main reason is efficiency. For example if burning fuel gives 100 units of energy most engines get around 15-25%, rest is wasted. How much energy is utilized, depends on a number of factors, and one of the most important factors is compression ratio, so diesels are inherently more efficient. Actually its the temparature difference, but higher compression ratio leads to higher temp difference, so it factors it. If you are interested in the actual physics(maths) its there in either the 11th or 12th standard NCERT textbooks(Atleast it was there in late nineties!). Or you can google for "Otto cycle".
One such link http://staff.science.nus.edu.sg/~par...c2/node44.html
Also you will notice that due to poor fuel quality in India, compression ratios are lowered. Due to this reason the same spec cars have lower FE and Power as compared to their European counterparts, esp in case of petrol engines where using a higher compression on bad fuel will lead to premature detonation.
There is research ongoing in Saab(maybe? dont remeber whch company) which developed a Variable compression ration engine which modifies the compression ratio depending on Fuel quality and driving style etc.,

[falcon]

Originally Posted by prasadee

Every 3 years the battery pack needs to be changed. It costs around $3000 for that, and the batteries needs to be disposed off somewhere, and it does affect the environment.

3 Years ? Toyota and Honda have stated that the batteries and the Hybrid System is designed to last the lifetime of the car.
They are giving a 100,000 miles / 8 year warranty on the Hybrid system!

Check out www.toyota.co.uk

[islero]

Originally Posted by falcon

3 Years ? Toyota and Honda have stated that the batteries and the Hybrid System is designed to last the lifetime of the car.
They are giving a 100,000 miles / 8 year warranty on the Hybrid system!

Check out www.toyota.co.uk

No, I think he meant the battery has to be changed, I think its not a problem as such, just part of the procedure, the warranty must be diffrent from what he's saying.

[prasadee]

Originally Posted by islero

No, I think he meant the battery has to be changed, I think its not a problem as such, just part of the procedure, the warranty must be diffrent from what he's saying.

My numbers are from 2 of my colleagues who are proud owners of Prius. The thing with such hybrids is that as the batteries get older and weaker, their charge/discharge efficiency decreases. Because the battery is maintained at a constant state of charge by the Prius computer, one would think that the ratio of input energy to output energy measured over a reasonable interval would give a good indication of the quality of the battery. This massive amount of charging and discharging, reduces the efficiency.

If you want to continue to brag about high mileage with your friends, it would be a good idea to replace the batteries. Of course the newer batteries are said to be getting better. Check this link out about the Camry hybrid.
http://www.chicagotribune.com/busine...ck=1&cset=true

[falcon]

Originally Posted by prasadee

My numbers are from 2 of my colleagues who are proud owners of Prius. The thing with such hybrids is that as the batteries get older and weaker, their charge/discharge efficiency decreases. Because the battery is maintained at a constant state of charge by the Prius computer, one would think that the ratio of input energy to output energy measured over a reasonable interval would give a good indication of the quality of the battery. This massive amount of charging and discharging, reduces the efficiency.

If you want to continue to brag about high mileage with your friends, it would be a good idea to replace the batteries. Of course the newer batteries are said to be getting better. Check this link out about the Camry hybrid.
http://www.chicagotribune.com/busine...ck=1&cset=true

The Prius has been on sale in the UK for nearly 10 years now and I have not heard of such battery problems with the car.
It is a known fact that the US model of the Prius is different from the UK model of the Prius, and the difference lies in the Hybrid System. Possibly the battery problems you talk about are restricted to the US
models only.
I have come across instances of US Prius owners trying to contact the UK Toyota outlets for the UK spares in order to overcome the faults with the US model.
And yes, I do not think "brag" would be the right word to use!!!

btw, the link you provided apparently requires registration. If possible, copy n post the article (I don't know if this is against the forum rules though... mods please advise).

Falcon

[falcon]

All,

Please excuse the second post...
I forgot to mention, I test drove the Prius today.
I have also got pics and a video of the IPA demo... Nice to see a car that can park itself!!!

Will post them soon.

Cheers,
Falcon

[falcon]

Originally Posted by islero

No, I think he meant the battery has to be changed, I think its not a problem as such, just part of the procedure, the warranty must be diffrent from what he's saying.

Toyota confirmed today that the warranty of 8 years applies to all the Hybrid components and that includes the Hybrid Battery pack. However, the regular battery IS NOT included in the Hybrid system and so had only the regular 3 year warranty.

Yes, if the regular battery fails, it can give endless problems when driving the Prius, and I think I read somewhere (can't find the link) that sometimes people mistake this "battery problem" to be a problem with the Hybrid batteries which is actually not the case.

Falcon

[prasadee]

I did not mean "brag" in any offensive way. I find it normal for Prius owners to be conscious of the fact that they own an eco-friendly, fuel efficient vehicle. I have another friend who has the Honda Insight, that gives even more mileage. They always find themselves talking about improving mileage. Things like plug-in hybrids, and newer, better batteries. I would be surprised if Toyota has designed Prius that is inherently different for US and UK.

That said I have considered the Prius several times, and I still think it is a great car. If you find out first hand that there is no degradation of battery performance after the first couple years, then kudos to Prius, Toyota, and its owners.

[falcon]

Originally Posted by prasadee

I did not mean "brag" in any offensive way. I find it normal for Prius owners to be conscious of the fact that they own an eco-friendly, fuel efficient vehicle. I have another friend who has the Honda Insight, that gives even more mileage. They always find themselves talking about improving mileage. Things like plug-in hybrids, and newer, better batteries.

Thanks for the clarification... no offence taken!

Originally Posted by prasadee

I would be surprised if Toyota has designed Prius that is inherently different for US and UK.

Several manufactures design US vehicles differently as compared to those in the UK and Europe... The ultra low fuel costs in US are one of the reasons for this apparently... The same applies when launching hi performance diesels... priority is given to the UK and Europe in this case too!

Forgive me for making a generalized comment, and I do not intend to offend anyone, but I personally feel that the people in the US have no value for fuel as it is so cheap! Out here we pay nearly 1 GBP for a litre of petrol, naturally that pinches our pockets and so we opt for vehicles with better fuel efficiency!

About the Prius in particular, I will trace the article that mentions the difference in the US and UK/Europe models and post it...

Originally Posted by prasadee

That said I have considered the Prius several times, and I still think it is a great car. If you find out first hand that there is no degradation of battery performance after the first couple years, then kudos to Prius, Toyota, and its owners.

I did take a test drive today. From the people I have spoken to, and the reviews I have read, I do believe that it makes sense... I have nearly made up my mind to buy it.

Falcon