Synthetic Oil – ‘Ask Ade’

Synthetic Oil – ‘Ask Ade’

With almost 30 years’ experience in the oil and lubricants industry, Morris Lubricants’ Automotive Product Manager, Adrian Hill, is perfectly placed to provide his expert insight and analysis. 

Q. I just checked for the correct engine oil for a 2005 Corsa 1.2 SXi and the answer appears to be Multilife C-THREE 5W-30 fully synthetic. I was under the impression that some fully synthetic oils can affect seals and gaskets, which can cause leaks. Does the oil have to be fully synthetic? Can I use part synthetic oil or just normal oil? The car is quite old and has never had synthetic oil so I’m a bit wary of causing any problems.

‘Ask Ade’ – Your lubrication questions answered


Synthetic oils, formulated for use in modern engines, are completely seal safe. All automotive products, including transmission oils, are designed to be compatible with all common seals/elastomers used in engine or transmission hardware.

There have been rare incidents where a synthetic  oil has been used in classic vehicles, with older style seals, where shrinkage has taken place and leakage has occurred. This is not a problem in the vehicle in question. The original oil requirement for a 2005 model of this designation was a fully synthetic 0W-30, so the design tolerances are more than capable of using a 5W-30 without any problems.

For more information on Morris Lubricants, click here. If you have a question for Adrian, email:

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