Re-fuel the tank in cool hours
H. Kishie Singh

PETROL has a very high flash point i.e. it ignites very easily. The slightest spark can fire up an explosion. Because petrol is highly volatile, it evaporates easily, especially in our hot and dry weather. If you were tanking up on a hot summer afternoon, you could lose a fair amount of petrol to evaporation. It gets metered as it is pumped in but the quantity that you will pay for would not have reached the tank. For this reason it is recommended that you re-fuel in the cool hours of the morning or evening. You will save money. Your fuel tank will hold more at cooler temperatures than at hot.

The quality of petrol has improved dramatically in the last year or so, thanks to the MPFI engines. They need unadulterated fuel, therefore, the oil companies were forced to improve the quality. Remember the Old Ambys and Premiers? They had to have the carburettors cleaned every time the car was serviced. With 5000 km of driving, the carburettor got choked with sediment. For this reason it was recommended that the tank should be topped up at night. This allowed the sediment to settle overnight and thus gave you a comparatively cleaner fuel. This also meant that the bottom of your tank was loaded with dirt. You either had to have the tank cleaned or had to keep the fuel tank full.

If you notice the army vehicles, they all have a date painted on the fuel tank with the initials PTC or DTC before it. If "P.T.C. 28.8.2002" is written, it would denote: petrol tank cleaned on 28.8.2002. The army moves on mechanised power and knows the value of a clean fuel tank. No choked filters and choked fuel lines. A blocked fuel line is another matter. You will have to undo the entire delivery system and blow compressed air through the pipe-line to clear it. When putting together the joints extreme care has to be taken to ensure a 100 per cent fit. Any loss of fuel will increase operating costs. Also, it will increase the chance of an accident. One drop of petrol falling on the ground, before it evaporates, can ignite and set off a chain reaction, allowing the flame to get to the tank. Keep in mind that the petrol vapours locked in a fuel tank are more explosive than the petrol itself.

Another reason to keep the tank full, especially in winter, is condensation. An iced drink collects condensation and moisture on the outside. In the case of a petrol tank, there is condensation on the inside. A few drops a day and in a couple of months, you could have a cup full of water in your petrol tank. This will eventually affect the performance of your car and sooner than later you will be forced to clean the tank and the carburettor. Do it the army way — on time!

Please pay attention to Snoopy in the accompanying illustration. Never leave your dog or your child in the car. Don’t leave grandpa in the car either. An elderly person can get suffocated, feel giddy and faint. A car parked in the Indian sun is like an oven. Other than dogs and humans, cell phones, lap tops, Casio dairies can get damaged due to heat. Ordinary plastic comes close to melting point.It is the driver’s responsibility where he parks and who and what he leaves in the car.

Another point to keep in mind. With every 6.50C or 100F drop in temperature, the tyre pressure drops by 1 pound per square inch (P.S.I) for instance. After a drive on hot tarmac if you drive up to Shimla for an overnight stay, tyre pressure of 22 P.S.I in Chandigarh at 35-450C could drop by 5 PSI after an overnight stay in Shimla, recording 50C. Your tyre pressure would be 17-18 P.S.I. Be aware of this. By the next morning the drivability and handling characteristics of your car would have changed. You would feel the difference in road holding, braking and cornering. The time to check tyre pressure is in the morning when the tyres are cold.

Happy motoring!