It depends on how much is being used up: If it’s more than 500ml per 500 miles or 1L per 1000 miles then yes, the engine may be on a downward spiral. It’s likely that the oil control rings are gummed in place by carbon, allowing excess oil to enter the combustion chamber and be burnt in the normal combustion process. The temperature inside the turbocharger unit is high and the oil is almost always evaporated by the time it gets to the exhaust and the catalytic converter, so you rarely see smoke on a hot engine. Monitor accurately the oil consumption and the miles covered and contact us to discuss options. It will consume more oil until one of the following two things will happen, and there is no cheap fix for either one
1. An exhaust valve will burn away as the engine will be running extra hot when low on oil and the oil burning much hotter than just fuel - this usually causes the engine to go onto two cylinders, it will have very little power and will sound strange 2. If maintenance has been sporadic the next thing to go will be a spark plug, the electrode will overheat if the oil is to low or oil will cover the plug and foul it - either way it will misfire.