The Hindu Business Line : Question & Auto

I bought a Mahindra Scorpio CRDe (Diesel) in June 2006. The fuel filter clogged and had to be replaced after I logged just 14,000 km. The Mahindra dealer I bought the vehicle from told me not to use `Premium' diesel and asked me to use only `Regular' diesel, as high octane diesel is usually responsible for this problem. Most petrol pumps are pushing for sale of high-octane fuels. Common sense suggests that anything, which is `more pure', should be better. So, this advise from the dealer workshop contradicts this common sense logic. The Scorpio's user manual too does not mention anything about which type of diesel to use. I checked M&M's Web site and found that it too does not talk about these issues and there are very few independent articles on the Net about this issue.

Arun Kumar Gupta

I own a Honda Activa. I started using XtraPremium petrol right from the start. Now I would like to change to Speed petrol of BPCL. Will a change of petrol cause problems for the vehicle? The three petrol brands — Speed, XtraPremium and Power — use leaded or unleaded fuel?

Dinesh Kumar

Almost all the premium fuels sold in the market today either have higher octane, special additives that ensure cleaner combustion, or both. Brands such as Speed, XtraPremium, Power and Turbojet are all petrol or diesel fuels that have additives, in many cases specially developed and imported, which are meant to clean injectors and remove impurities from the engine chamber.

These slightly more expensive, branded fuels have specialty chemicals that act as detergents, cleaning deposits such as soot, resins and `coagulated' un-burnt fuels that may have accumulated in the injectors and engine components.

We have not tested the efficacy of each oil marketing company's claims, but generally, these fuels are expected to be beneficial to the engine, and are capable of reducing knocking, improving fuel efficiency and, in the long term, may even help increase engine life.

But, unfortunately, there are two issues that most vehicle users who choose these branded fuels tend to forget.

One relates to the fact that the blending proportion of the cleaning chemicals to the base fuel is calibrated for efficient performance only when used undiluted. There may not be any benefit if, for example, a user fills half the tank with regular fuel and then fills remaining half with branded fuel.

Another point to remember is that the special chemicals that are present in the branded fuels, while cleaning the engine and injection components, also tend to clean deposits in other components too like the fuel tank. Deposits from previously filled poor-quality fuel, dust and deposits from ambient conditions and entry of deposits while the fuel is being vended can all increase the level of impurities in the fuel tank.

These impurities may then get dislodged when premium fuels are used, leading to a sudden increase in accumulation in the fuel filter.

The clogged fuel filter will, therefore, need to be replaced even before its rated useful life. If deposits accumulate in the fuel tank floor to a point where it corrodes the metal body of the tank, you may actually have to replace the fuel tank.

All branded petrol fuels are unleaded. In fact, there is no other type of petrol but unleaded (including unbranded), that is currently sold in the country.

I recently approached the neighbourhood Maruti dealer to buy a Suzuki Swift. He quoted a higher price for the Swift VXi than the rate mentioned in the company Web site and said that it was because a new safety feature had been added to the car. On further enquiry he said that it is a new anti-theft device called iCATs. Is it right, and is it worth the higher price?

Sundeep Ray

The anti-theft device that Maruti recently introduced in all its passenger cars is essentially a digital engine immobiliser.

The immobiliser, called iCATs (Intelligent Computerised Anti-Theft System), is an electronic system that works on digitally encrypted codes that are designed to be tamper-proof. Cars equipped with iCAT have a secret code on the main key fob. Every time the car is opened or the engine cranked, this code is matched with the corresponding code on the ECU (Electronic Control Unit) of the car. Only when the two codes match will the ECU permit ignition of the engine.

Factory-fitted anti-theft systems are common in vehicles sold in advanced markets such as the EU and Australia. Maruti's initiative to introduce in all its vehicles is a first for India.

Immobilisers are reliable as they work on the principle of digital communication between the ECU and transmitter in the key, which technically cannot be tampered with. On the other hand, most aftermarket `theft-deterrent systems' currently sold in India rely more on wiring and movement sensors alone. These are relatively easier to disable and are as such less reliable as theft prevention devices.

With the introduction of the iCATs, the original set of car keys becomes even more important for Maruti car owners.

In case of loss of the car key, only the original second key will start the car. Company officials say that, if needed, customers can order replacement keys at Maruti dealerships after proper authentication. The Maruti dealer network is trained and equipped to handle customer needs. But this also means that making duplicate keys at the street-corner key-maker is ruled out.

In terms of benefits to customers, the new iCATs device should be able to dramatically reduce the risk of theft for Maruti's car owners.

The increase in the sticker price for various Maruti models that are now offered with this anti-theft device should be offset over a few years, thanks to lower annual insurance premium that the insurance companies are willing to offer.

A rebate of Rs 500 is being extended on the insurance premium payable for cars equipped with iCATs.

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