10th Mar 2010, 05:57

The oil sludge issue on the 1.8T seems to be particular to North America. Here in the UK this engine has been sold for about 13 years, and sludging is almost unheard of, despite 10,000 mile oil change intervals, or more if the car is on variable servicing. Sludging in general is something that died out in the UK and Europe about 20 years ago with the advent of good quality synthetic oils.

I've noticed when in the US, that although people are much more conscientious about oil changes than the UK (here, nobody would even dream of 5,000 mile changes on a mass produced car), you also seem to use much cheaper / lower grade engine oils. Here, we stick to manufacturers intervals which are between 10,000 and 20,000 miles depending on the servicing regime the car is on, but are happy to pay UKP 40-50 ($60-$75) for a top quality manufacturer specified synthetic engine oil at service time. Bear in mind that's the oil cost only, without labour or other parts. If you went into an oil change shop and they quoted you $90-$100 with a new filter and labour, would you pay it?

I hate to think what oil the typical $20-$30 drive in oil change uses, and seriously doubt it meets the stringent standards laid down by the designer and manufacturer of the engine. The impression I have is that the servicing culture in the US is geared around traditional low tech, 40 horsepower per litre pushrod engines using low grade oils, rather than the ultra-tight tolerance, high output engines and stringent oil requirements that are involved with modern European cars.

Although more expensive, these new generation, tightly specced synthetic oils are easily good for 10,000-12,000 miles, or more in some cases and in some engines. I cannot think of a single mainstream car on sale here that needs, or ever gets servicing more frequently than this, nor one that, treated as such, wouldn't still be running sweetly at 150,000 miles. The UK's problem is that many people don't bother servicing cars at all once they get past about 5 yrs old, but that's a different point.

Of course it is a manufacturer's responsibility to test its products in all target markets, and to ensure that specifications for oils and other fluids are clearly laid out, and the correct products are readily available. This should have been picked up and corrected by Volkswagen and Audi, and American drivers shouldn't be penalised for doing what they've always done and running cars the way they always have. But I can't help feel from what I have seen that the root cause of the 1.8T sludge issue is more a cultural problem than an engineering one, given that it doesn't exist outside North America.

In an old-tech engine, cheap oil changed frequently was a recipe for a long life. In a modern European engine, it's a recipe for disaster. The oil spec is everything, and like most things you get what you pay for. Oil specs also vary between manufacturers, meaning a workshop servicing 10 makes of car would probably need 5 or 6 oils in stock to ensure even basic compliance with the specs. The 'one oil fits all' idea died here years ago, although Volkswagen and Audi should be shot for using engineering specs (502.x, 505.x etc) for oils which mean less than nothing to the layman, and are bound to result in mistakes. The fact this problem doesn't occur outside North America, and is almost unheard of on any engine in Europe, suggests that the problem is down to the oil, rather than the engine. The only other difference I can think is that cars here in Europe tend to be driven harder and faster than those in the US, which could play a part. That said, there are people here who drive like Miss Daisy, and don't have a problem.