Friday, June 24, 2011

What's wrong with Prius ?

So, here we are again! As promised, in this post we will discuss whatever we know as cons in Prius. For those who are already feeling like left out : In part1 of this post we discussed few basics in Prius, in part2 we covered bit more detailed stuff.

Most of those stuff discussed in those previous posts, I could personally vouch from own experiences. Sadly, (for the readers that is :-) ) I can't vouch for most of things we are going to discuss today since I still haven't had the misfortune of experiencing many of them myself. (yet!)

Issue 1, Prius need a baby sitter!
Rechargeable battery is NiMH, so it is not good for this battery to be idle for a long time or fully charged or low charged for a long duration. While driving, Prius is making sure that the battery charge is around 50%-60% most of the time so that it's life will be prolonged. However, when the car is parked and idle, it is the owners responsibility to make sure the car doesn't stay like that for weeks continuously, that will make the battery fully dead!

In 2001 model, Toyota issued a open warning that if the car remained idle for 3 continuous weeks, the battery will be irreversibly and permanently damaged. (that could be a loss of about $ 2000-3000). So if you are out of home for such a duration with the car leaving in the garage, you will have to ask someone to start it and go for a little ride (or at least start and let the engine run for few minutes) once in every few days!

Believe it or not,  This actually benefited me! When I bought my car from a local dealer in 2005, they have put it in the show room for few months without knowing what that would do to the battery. So, they had to import and fix a brand new battery before selling the car to yours truly. That battery is still working in acceptable quality. Also, I'm not a person who get to leave the car alone for weeks on end, So the baby sitter problem was never an issue for me. 

Issue 2, crash impact on the rear could ignite the battery ?!
A Toyota engineer told me this. This has to be a severe crash, which is very rare so the available information is scarce. A quick search in the net will find you few cases but most of them have following characteristics. Either someone has put the car on fire deliberately, or this has happened to a plug-in hybrid (we will discuss this in little later) or the car got in fire for some other reason and what they are really claiming is it's difficult to put the fire off when it got close to battery compartment. So it's not really clear whether there is a proven fire issue in Prius. If there is one it is unlikely the car comes to the global market after passing safety tests. So I guess at most, this is a very rare case of a normal fire spreading into the battery pack. Even in a normal car, a fire could be lethal if it spread near petrol tank for instance. Nothing to fear about but something better to keep in mind I guess.

Issue 3, overall performance can degrade in extreme cold
This has been witnessed in some countries in winter. Little drop in battery performance and also due to engine heating required, I guess. Not an issue if you not going well into minus degrees often.   

Issue 4, performance can go down temporarily after sitting under hot sun for hours.
This too I heard from a Toyota technician. Curiously enough, I haven't seen a noticeable effect myself! May be it has to do with the high power needed for AC for a while after being under the sun, or may be the electrical parts performing sub optimally under excess heat.. We would like to hear from new model owners whether they see a difference. Meanwhile, it's better to park your car in a shade when ever possible. :-) 

Issue 5, Don't get it dropped in water or get caught in severe floods!
There is lot of electrical parts, computers and batteries inside.. So, water is understandably allergic to the internals of this particular animal. When cleaning or servicing, don't let people to use the water gun at the engine area! (after opening the bonnet) that part needs to be cleaned by air, not water.

If the the extremely funny case of car getting dropped in a river or a lake and the driver surviving, if it is a normal car and if you somehow manage to get it out of water, you would expect it to run after some basic repairs and servicing isn't it ? but not the Prius! In this case you would be most probably in for some series repairs and troubles with the electrical parts... Same goes for getting caught in severe flooding. I guess this is an extreme but an obvious case, so no need for further explanations. If you feel like taking a dive or two together with your car once in every year like, then the Prius is definitely not for you. :-)

Issue 6, reversing could be a problem when the battery is really weak.
New car owners will not see this for at least 10 years I hope. My old car sometimes gives up this complaint. This happen when the hybrid battery is weak and not charged to the expected level. Prius relies on the battery for the reversing. (at least my old model is, check with your one!) So, if I have to reverse a long distance, or worse reverse uphill then the car would simply not move! Will have to shut off the engine and start again in this case, sometime I had to do this few times. It can be embarrassing in a crowded park for instance. Fortunately this is a rare case even in my old car and can be averted by making sure the battery is charged before you leave the car (keeping the engine on for a little while), or avoiding parking in such ways as you have to perform a reverse uphill to re start your journey. As mentioned in part1 of the post, this problem went away after servicing the battery.

Oh.. we almost forgot to mention about the plug-in hybrid! This is a new model of Prius which is now being tested in few continents and expected to hit the markets next year. This can we can optionally charge in the night from the main line and can go up to 30 kms in a single charge without using a drop of petrol! This is in addition to behaving like a normal Prius.

Few observation :
1) One might think this is totally green but not necessarily so. If the electricity is being produced in a power station using fuel, then car is still indirectly runs on fuel. However, power generators uses fuel much more efficiently in converting them to electrical energy than a vehicle engine converting fuel into kinetic energy, so you are still making a contribution to the environment. Another aspect is sometimes electricity you use at your home is being produced by nuclear, hydro or solar power. In those cases, it will be a 100% fossil fuel free ride for you!!

2) One might think this is very cheap than running on petrol but not necessarily so. It depends on how expensive the electricity is in the country you live. I don't think this will be that cheap in Sri Lanka. However, in certain countries wherre they have abandon nuclear energy, this could turn up to be a big save and total independence from fossil fuel as well!

3) Even your current Prius can be turned into a plug-in model! There are 3rd party battery charges available in the market. (got to eBay for instance) using one you could charge the batter at night. However, these technologies are not recommended or endorsed by Toyota. In fact, they will  make your warranty null and void if you get caught using such a device. There are people who still do this, but it is advisable you do it knowing what you are doing and taking a risk as well. Personally I wouldn't even think about this until one day the electricity become cheap in here. Until (if/when) minster Champika Ranawaka get his nuclear power plant operational that is.

Ok... we are closing the shop now. I have no intention of writing any Prius articles any more. (at least not in near future) I didn't really intend to write 3 posts as I have ended up doing! Very happy to see the interest it generated and if these information were helpful to anybody somewhere. We can discuss more via comments.

See you next time then...

Tuesday, June 21, 2011

ශ්‍රී ලoකාවේ හොඳම මිතුරා කවුද ?

ශ්‍රී ලoකාවේ විදේශ ප්‍රතිපත්තිය කෙසේ විය යුතුදැයි නොයෙකුත් මතවාද මේ දිනවල අසන්නට ලැබේ. සාර්ථක විදේශ ප්‍රතිපත්තියක මූලිකම කරුණක් වන්නේ සැබෑ මිතුරන් සහ සතුරන් හඳුනා ගැනීම ය.  අනෙක් සියලු ක්‍රමෝපායන් හා උපායමාර්ග සකස්වන්නේ ඉන් අනතුරුවය.

අපගේ නියම මිතුරන් සහ සතුරන් කවුදැයි දැනගැනීම වැදගත්කමින් දෙවැනි වන්නේ අප කවුදැයි දැනගැනීමටම පමණක් යැයි සිතමි. රටකට එය වඩාත් එසේය. නිදහසෙන් පසු අපට වඩාත්ම හොඳින් (සාපේක්ෂව) මිතුරෙකු සේ සලකා ඇත්තේ කුමන රට ද ?

වැදගත්ම අවස්ථාවකදී අපට යම් තෝරාගැනීමක් කිරීමට සිදුවුවහොත් අප විසින් තෝරාගත යුත්තේ කුමන රටද? අසීරු අවස්ථාවක අපගේ පිහිටට එතැයි තරමක් හෝ විශ්වාස කල හැකි රටවල් අතර එය ක්‍රියාවෙන්ම පෙන්වා ඇති රටවල් වේද ?

ඇත්තෙන්ම මෙය එක එල්ලේ පිළිතුරු දීමට තරමක් අපහසු පැණයකි. ප්‍රශ්ණය පැති කිහිපයකින් බැලිය හැකි වීමත් අප අතරම පවතින විවිධ මතවාදීය වෙනස්කමුත් ඊට හේතුන්ය. කෙසේ නමුත් මෙය හැකිනම් පිළිතුර දැනගැනීමට වටිනා පැණයකි. එසේම, අවශ්‍යනම් එසේ දැනගැනීමට හැකි ක්‍රමයකුත් ඇත! ඉතින් ශ්‍රී ලoකාවේ හොඳම මිතුරා සොයා ගැනීමට උදවු වීමට ඔබත් කැමතිද ?

මෙන්න ක්‍රමයක් ....

දකුණු  පස ඇති මත විමසුමෙහි ඔබේ තෝරාගැනීම සටහන් කරන්න.

ජූලි 3 වනදා වනවිට "ශ්‍රි ලාoකිකයන්ගේ මතය අනුව" ශ්‍රී ලoකාවේ හොඳම විදේශ මිතුරා සොයා ගැනෙනු ඇත!

මත විමසුම සඳහා ඇති සබැඳිය (in google polls) මෙය  වේ. ඔබට බ්ලොග් අඩවියක් ඇත්නම් මෙය ශ්‍රී ලාoකිකයන් වැඩි පිරිසක් අතරට ගෙන යාමට උදව් වීමටත් හැකිය.

ඉදිරිපත් කර ඇති රටවල් අතර ඉන්දියාව, චීනය, ඇමෙරිකාව, පාකිස්තානය, එoගලන්තය, ජපානය වේ. රුසියාව ඇතුලත් කිරීමට අතපසු වීම සමීක්ෂණයේ සිදු වු අඩු පාඩුවකි. 'වෙනත්' රුසියාව සඳහා යොදා ගත හැකිය.

Sunday, June 19, 2011

Toyota Prius Hybrid - Experiance from a user, Part 2

Part 1 of this was something I just casually wrote in the hope of it will be of some use for few. Turns out there were lot of readers than I anticipated! May be it will not be a bad idea to share some of more detailed stuff too... Things I didn't put in the first post since I wasn't sure about the level of interest on technical details of a  Prius.

Tires : My model came with the most uncommon type of 165/65/15 low resistance. This was the type recommended for 1997 model Prius. Since fuel consumption statistics, mileage meter all must be depending on the tire radius size, all the statistics the car indicates to us could go wrong if we change the tire radius. However, using a different tire radius is not possible without changing Rims so I guess this is not a common scenario. However, tire inflation level is! Fuel consumption difference between using properly inflated tires and poorly inflated ones can be noticeable! When the tire is deflated, the length it covers per a single rotation is less, hence more rotations will be needed to cover a unit distance, resulting in high fuel consumption.

Surprisingly, 1997 model recommended tire pressures to be at a staggering 42 psi. Normally in Sri Lankan roads we use a pressure level of 28-32, most people preferring 30. in 1997 Prius, front wheels needed to be pressurized at 44 while the lower once were expected to be at 42. Difference was to offset the additional weight of the front area. Now, I infact tried those! want to know what happened ? Well, I got amazing fuel economy for a while and then I had to replace shock absorbers! Understandably, I haven't tried it since then. This setting is certainly not for non carpeted roads of Sri Lanka. Then again, we have much better roads now compared to 5 years earlier and if you are one of those lucky ones who can use a carpeted road all the time, then you should definitely give this a try. Inflating tires is a well known strategy to conserve fuel, something which was even suggested to all Americans by Obama himself!

Breaking : Because of the electric breaking in Prius, it is expected that one do not need to replace break pads that often. Can some one give us some statistics on this for a normal car? in my usage of the car for 6 years (close to 100,000 km)  I had to replace break pads just once. Like mentioned in the previous post, most of Prius parts are compatible with other Toyota models, and Toyota parts are not so expensive either so this was not something to boast about really. On the other hand, regenerative breaking is saving much more in fuel than saving on break pads. Statistics say that if you use it properly regenerative breaking can save up to 17% of the kinetic energy which will otherwise go totally wasted. Here, 'properly' means that to get the full benefit of regenerative breaking, we need to apply breaking smoothly. A gradual slow down of the car over a distance where we can clearly hear the humming noise of breaking. A sudden break will not be turning much of kinetic energy into electrical energy. (but it will save lives in an emergency! so do apply breaks with full force when you have to...)

Fuel economy hints :
This fact has been mentioned before but let me go through it again as this is the single most, biggest reason behind fuel wastage, even on a hybrid!

Trying to speed up (accelerate) when that is not really needed or meaningful.

How many times we see someone overtaking us, but then we catching up to them after driving normally while they are waiting at a color light! That is insane driving, we get no benefit at all by accelerating and be the first to reach a particular color light! If we know there is a stop in front, best and most sensible thing to do would be to stop accelerating and allow the vehicle to slow down, we could time this to perfection so that the vehicle stops at the exact spot is should be stopping. Doing that is much fun too! On highway, the strategy should be to drive in a comfortable constant speed (around 30-70) by tapping the accelerator lightly. Display should tell us when we are doing well in fuel economy. (instance bar hovering around 30 km/l) It is those occasions that we should try to lengthen. All these help us concentrate more on our driving and speed, which make us good safe drivers. Some of US states have actually reduced insurance amounts for Prius noting that Prius drivers get involved in far less amounts of accidents than the others. I guess this applies to other hybrid drivers as well. Being sensitive to fuel economy and be attentive to driving both go hand in hand.

As mentioned in the last post, a one cool feature of Prius is that the engine can automatically stop when the vehicle is idle (like waiting in traffic). This saves lot of fuel in city driving. However, this also means that the engine get auto started when we eventually start to move. (initially the vehicle goes solely on battery and then switch into petrol) When the engine get stops and started again frequently like this, it will put up a higher burden on the normal 12V car battery. If the Prius has to perform well, this 12V battery also need to be in good shape. Needless to say, power steering also is on electric so the stress on this battery is really high. This is one lesson I learnt after going through some hassle. It is natural to pay more attention to the bigger costly battery and forget about the little one. So make sure you keep a good eye on the little 12V fella as well!

One caveat in auto stop and start of the engine is that it works as expected mostly only when the AC is not running! reason ? In older models of the Prius (such as my one), AC gets the power from petrol engine like in any other normal car, so if the AC has to work, you need the engine running. In this case, sometimes even if your vehicle is idle, petrol engine will keep running. Turning AC off when the car is at a stop is not always possible in hot days. However, in recent models (after 2003 I guess) Toyota has improves on this by making AC also to run on battery! So the owners of newer models... let us know whether petrol engine totally stops at  traffic (while AC is fully on)

Looking at the fuel efficiency more on the LCD display is a great way of adjusting our driving. In a display like the image above, rightmost bar is our instance performance that is how many km/l or miles/gallon are we doing RIGHT NOW. Other 6 bars are average fuel consumption in last 30 minutes divided into 5 minute periods. One thing you will see most of the time is that the average efficiency in the first 5 minutes of the journey is usually low. Reason for this is that the petrol engine (of any vehicle) needs to get heated up to a optimal temperature to perform well. Until it reaches that point it can't maximum efficiency. This means if the usual drive is about 20-25 minutes or shorter, then the overall fuel efficiency suffers noticeably due to the first 5 minute issue. In later models Toyota engineers have come up with an ingenious solution to improve on this. They have introduced a vacuum flask which will keep all the heated air when the engine stops and use that when the engine get started next time. This reduces the need to heat the engine all the time. Just a one example how far designers have gone to provide the maximum mileage for each drop of fuel..  

What about things which can go wrong... (As Murphy's laws predict, "If something can go wrong, it will - at the most inappropriate moment") I have some experiences to share on these issues as well. Will try to share them with you in another post. Meanwhile, feel free to send in any questions and your own experiences, those will be most welcome!

Happy, Safe, Clean and Economical Driving!