Car needs an oil change, and I can get a good deal on some fully synthetic
Cheers
Hellraiser.............>
The 5W rating should just make for easier starting and better oil flow in the winter in a cold engine. The 40W rating is when the engine's hot and is usually the more important one so I wouldn't worry. The owner's handbook probably has a guide to oil grades vs. local climate temperature ranges.
Cool, I was concerned that being thinner when cold it may provide less protection from cold than the 10w40 stuff, as whilst it may travel around the engine easier, if it's thinner then it won't cushion the moving parts quite so well... I understand synthetic oils can cause issues with oil seals if they are used to mineral oils, but as I've been running on semi-synth I take it this is unlikely to be an issue?
Cheers :)
Hellraiser...............>
The oil should be the same viscosity once upto temperature.
My cars has used 10W-40 (semi-synth) for years, as per the manufacturers recommendations - but I recently switched to 5W-40 (semi-synth) without problem.
This is a falacy, if you have a leak now you'll have one then, if not you'll be fine. You may see an increase in leak speed if you throw in
5-40 as its thinner when cold, hence will leak easily. Been switching to and fro from mineral to fully synth on cars since i started driving. JHave something to add? Share your thoughts — no account required.
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