How much oil has your engine lost?
Advances in oil technology, filtration, PCV and engine management systems seem to have convinced everyone that frequent oil level inspection and services are unnecessary. But David Tenpenny of BG Technical Service is keen to communicate the message that it doesn’t mean your oil doesn’t need checking and that oil consumption doesn’t happen. Once excessive oil consumption has been determined, he says, little can be done to effectively reverse the problem. The only way to reduce oil consumption is through routine maintenance with the BG Performance Oil Change.
Technology changes may have reduced the need for motorists to carry out more frequent checks on their engine oil levels, says David Tenpenny of BG Technical Service, but it doesn’t mean that oil consumption problems have been eliminated. In fact, he maintains it is one of the leading problems related to driveability concerns in automotive service centres today.
GM says consumption of approx. 1 litre every 1,000 miles/1,600 km is acceptable. Porsche says approx. 1 litre every 750 miles/1,200 km is OK and VW and Audi recently declared that oil consumption of approx. 1 litre every 650 miles/1,000 km is normal on their cars. David agrees that some oil loss is inevitable and even acceptable, but never at these levels, he says and never on low mileage vehicles.
What causes oil consumption?
Perhaps not surprisingly, today’s recommended extended oil change intervals top the list for causing oil consumption. Extending service far beyond its ability to protect, rapidly allows for sludge, varnish and carbon deposits to form. Early tell-tale signs of oil consumption used to be a blue smoke haze leaving the exhaust. But today’s catalytic systems remove the evidence that was once apparent years ago.
Today’s low viscosity oils naturally lead to greater oil volume loss than previous generation oils. The current API category standards today allow up to 15 percent oil volume loss. Lower viscosity oils allow emissions to enter into the PCV system causing sticky deposits to form in the intake and on the valve stems and obstruct the incoming air.
Another new engine design innovation used today is Low Tension Piston Rings – lower elasticity in the piston rings. Reduction in piston drag allows for easier engine rotation, but is also prone to allow a large volume of cylinder compression to escape. This contributes to higher than normal crankcase pressure carrying oil droplets (again via the PCV) to the intake and on toward the combustion chamber to burn.
The process of combustion carbonises oil deposits on piston tops and combustion chamber surfaces. The hard deposits can lead to misfire, poor fuel economy and a noticeable drop in performance.
A consequence of oil burning is that it will pass through the exhaust and deposit onto the catalytic converter. This also affects the ECM’s ability to control driveability and operational function.
What can be done?
Once excessive oil consumption has been determined, David says little can be done to effectively reverse the problem. The only way to reduce oil consumption is through routine maintenance with the BG Performance Oil Change. This service includes:
- BG EPR™ Engine Performance Restoration, PN 109, softens and dissolves hard-to-remove deposits from piston rings
- BG MOA,® PN 110, Engine oil supplement, prevents engine oil thickening under even the most severe driving conditions
- BG 44K,® PN 208, Fuel system cleaner, quickly and effectively cleans the entire fuel system
Used together, these three products have been proven to keep engines clean and prevent potential complications like “inevitable oil loss.”