Hello, Mr. Ferman. We were planning to buy a brand-new Hyundai Grand Starex Gold, but we postponed the purchase after talking to a mechanic here in Cavite. He told us that the reason the Grand Starex's CRDi diesel engine is powerful is because the diesel fuel supposedly passes through a "catalytic converter" or some special filter before going to the engine. According to him, when said filter is consumed or becomes dirty, it loses its effectiveness and the CRDi engine suddenly loses its potency. He added that some Grand Starex units get returned to the service shop even when new, just to have the aforementioned "catalytic converter" replenished.
Is this true? Isn't this dangerous if, say, you're going up a hill and the engine suddenly loses its power? Also, if true, then that would mean you need to keep having the "catalytic converter" fixed throughout the life span of the vehicle.
I hope you can enlighten me on this as our family is really considering the Grand Starex van.
Vicente Yuson Gatchalian
There is really no difference between the design of the Grand Starex's CRDi diesel engine and those of other modern EFI (electronic fuel injection) diesel engines used by Toyota, Mitsubishi, Isuzu, BMW, Mercedes-Benz, Audi and Kia, among others. Most modern EFI diesel engines have a high fuel pressure and really require servicing at some point so the fuel filter may be replaced. If this fuel filter isn't replaced at the right time, the engine will indeed lose its potency. The same is true with gasoline engines.
As for the catalytic converter, its function is to treat or catalyze the emissions coming out of the engine so that it becomes less toxic for environment's sake. Perhaps what the mechanic was referring to is the particulate trap located in the exhaust system of a modern diesel engine. Its function is to burn the soot particles that accumulate inside the exhaust system so as to prevent its clogging. A clogged exhaust system will indeed result in reduced performance.
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