Comments by "David Elliott" (@davidelliott5843) on "Does Liqui Moly CeraTec work? Let's find out!" video.

@daviddefortier5970 "Engine restore" was almost certainly just as ineffective.
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@BL-yj2wp Every gallon of petrol (gasoline) burns to a gallon of water plus CO2. If the car is used for short journeys (never getting fully hot), some of that water gets into the crankcase and will contaminate the oil. A blown cylinder head gasket can allow coolant into the engine oil, but the engine would soon be overheating and obviously not well. Continuing to drive like that would kill the engine. Oil contamination would be the least of your worries.
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@jusb1066 Big goods vehicles and mobile plant engines use ultrafine bypass filters. These take about 10% of the oil flows and scrub away the contaminants. This allows the various additives used in engine oils to last so long that oil changes are needed far less often. Normal top ups are enough. The cost benefit on car engines makes it better to simply change the oil when its depleted.
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@n325aej Lead was used to raise the octane number so cheap petrol could be used in high compression engines. Valve seat protection as a byproduct.
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