3000 miles a year

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Sun 21 Jan 2001 10:01
3000 miles a year - steve human
what is the effect on a catalysed engine of constant short trips around town, where the engine doesn't ever warm up and is a non catalyser better for this kind of driving? i am concerned with costs of wear and tear.
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Sun 21 Jan 2001 13:12
RE: 3000 miles a year - honestjohn
The engine and exhaust system will fill with condensation which never dries out. The effect of this on the engine will be to emulsify some of the oil, possibly blocking oilways with globules of mayonnaise. The exhaust system will always be damp inside, which is bad for the cat but will lead to the rear silencer box rusting from the inside out. The other problem is overfuelling because during short runs from cold the ECU runs the engine in an over-rich cold running cycle (a bit like the old 'choke'). This overfuelling will lead to the bores being washed out by neat fuel and accelerated bore wear. Sometimes the ECU will prevent the engine from starting in order to protect the cat from unburned hydrocarbons (neat petrol). If you overcome this by pushing your foot right down on the accelerator to try and match the high fuel rate with a high air rate you run the risk of spiking the cat (destroying part of the cat matrix), creating a 'hot spot' which eventually causes the cat matrix to disintegrate.

HJ
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Sun 21 Jan 2001 19:56
RE: 3000 miles a year - steve human
thanks for that. are there greater problems with diesel (and turbo diesel) engines on sort trips or would frequent oil changes be the answer? steve
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Mon 29 Jan 2001 18:27
RE: 3000 miles a year - R Baker
Your advice is sobering. I was intending to buy my wife a new small car but there is no doubt it will be used largely for short trips. She is fed up with driving my ancient Peugeot 309 - no PAS and dents! It seems silly to buy a new car only to abuse it. Would I be wiser to get a pre-catalyst model? Can you advise on how to limit the damage, other than by doing unnecessary longer distances.
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Mon 29 Jan 2001 23:49
RE: 3000 miles a year - Andrew Hamilton
Whats wrong with your Peugeot. I like them. New car will have horendous depreciation. Why waste money. Spend it a few cruises instead!
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Sun 21 Jan 2001 21:53
RE: 3000 miles a year - Andrew Hamilton
My sister runs escort diesel, my brother in law runs Turbo diesel panel van, I drive LDV200 diesel van. Great for short journeys. Exhaust lasts for ages. Actually corrodes more from outside than inside condensation.
No catalyst. Simple - no ECU. Only MUST use best diesel(lubricosity rating) and ensure fuel filter changed early.
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