In today’s column, I will answer some of the queries I have received. Feel free to write in with more.
QI would like to know why brand new common-rail diesel cars emit smoke on fast acceleration. Is it because of the poor quality of India’s fuel?
QI have always been told that water in a car battery should be topped up completely and that it should be checked frequently. However, I was recently told by service engineers that the water just needs to cover the grill plates sitting at the base of each cell. Is that correct? Why do calcium deposits collect on the battery top? Is that normal?
To answer your fir st question: Our emission standards have been modelled on the European Urban Driving Cycle, which tests cars from cold at particular speeds. As far as I can tell there is nothing mentioned about emissions across the engine’s rev range at wide open throttle, which makes sense — one will not spend too much time near the redline with one’s foot to the floor.
I cannot comment about the quality of India’s fuel at this point of time since I haven’t found any freely available data about it. However, you should know that BMW kept their diesels away for a long time because the sulphur content in our diesel was too high. So don’t be surprised if you see a fast-accelerating premium car that drinks the sticky stuff emit a little smoke while on the charge.
Coming to the second: Car batteries used to require regular top-ups of electrolyte until a while ago, but the latest breed are ‘maintenance-free’. This means that the electrolyte does not need to be topped up every so often. The white deposit you’ve seen on the top of the battery isn’t calcium; it is lead sulphate, the chemical that helps your battery store electrical energy.
Please do not touch this substance with your bare hands, it is corrosive and is especially harmful to your eyes.
This deposition occurs routinely, since it is one of the effects of the electrolysis in your battery, but it is not desirable. The terminals are usually cleaned and coated with petroleum jelly during service to prevent this.
If your battery overcharges, the water in it will break down to oxygen and hydrogen; you may have to top it up with a little distilled water then.
QI drive a Honda City which has run around 32,000 km. The tyres are radial, tubeless, company-fitted ones.The front left tyre was recently punctured as a result of a small cut on the side of the tyre. The repair guy put a patch on the inside of the tyre to fix the puncture and also put a tube inside the tyre to prevent it being punctured again.
Now, while the rest of the tyres are tubeless, the front left tyre has a tube. Is this safe? Please advise.
The tube will not prevent the tyre from getting punctured; it is usually used as a stopgap measure if a tubeless puncture repair kit isn’t handy. You should either get your tyre repaired and use it without the tube, or purchase a new tyre if the cut in your tyre is too big. Putting a tube in a tubeless tyre will give you no benefits whatsoever.
The cut in your tyre is on the sidewall, so it most probably isn’t covered by the tyre warranty. Do check with your dealer for further information.
QI like your article in Hindustan Times. I want detailed information on two-stroke and four-stroke engines. Please suggest a site or book where I can find this.
I’m glad you liked the column. You can find a lot of information about engines in the “How car engines work” section at www.HowStuffWorks.com. I also find the ‘Car Bible’ series of articles on the Web (www. carbibles.com) very informative, but not as easy to understand as the former.
Look up the Fuel and Engine bible here which will tell you more about engines. These two sites should be more than enough for a person beginning to learn about engines.
Any first-year automobile engineering textbook like Kripal Singh’s will have the necessary information on engines, but my personal recommendation is to try and use the Internet first — it is a very effective tool when used right.
Textbooks may just have you swimming in a sea of jargon.
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