Oil change on time interval ?

[Terry57]

Hi there,
I have purchased a MY14 VF Evoke Sportswagon V6 with 175 K on it. Next service is due at 185 K . Thing is im overseas for 7 months of the year and only put around 10 K a year on a car.

So when i return to Perth in October the service history tells me its due for oil and filter change.

My question is this. Considering the high quality oil used in this vehicle is it important to change the oil considering its 10 K away from actual miles done. ?

Does full synthetic oil deteriate with age or is it not necessary to change it. If i must change it l will do it no probs.

This vehicle is ex CBH fleet vehicle and has been fully maintaned . Very nice car and runs like a clock.

Thanks very much for any qualified advice.

 

[gossie]

It's very quick and easy to change the oil on them.
Just drop it yearly along with a change of the filter, and top up with the oil you like to use.

 

[stooge]

Just change it.

 

[Forg]

Full synthetic still deteriorates, just not as quickly.
If using synthetic & barely putting any km’s on it & not doing craploads of short trips where the engine+oil doesn’t get properly warmed up, I’d be comfortable with yearly oil changes - assuming outside of warranty of course, in warranty you want to go by the book to keep the beancounters happy.

My wife’s the main driver of our SSVR, and we’ve been doing 9-monthly services to the book ‘cos 5yr warranty. That warranty expires in December though, and I’ll be changing to yearly services, it only does 7500km/yr and she drives with a fairly light go-pedal foot.

 

[Terry57]

Yer, thats what i figured. Just do it once a year and job done.

Ta.

 

[Voodoo_SV6]

My HSV did 3000Km last year, still gets an oil and filter change yearly - fully synthetic (book says 9 months/15,000). My EH (fully rebuilt) did about 2500km last year, runs only on mineral oil, gave it an oil and filter change 10 months after the previous, just so I could have both of the weekend cars due at the same time.

 

[MattSAU2XR8]

Obviously if the car is in warranty I'd be changing it as per the schedule

But it's hard to imagine it deteriorating as fast as when the engine is being used if its parked up.

Just to refresh my memory I had a look for a few references (see below) and they propose that oil deteriorates due to the following...

Heat Oxidation Viscosity loss (shear) Wear metal Fuel contamination Combustion blow by Additive depletion Moisture

https://www.amsoil.com/newsstand/motor-oil/articles/why-motor-oil-deteriorates/

http://what-when-how.com/automobile/oil-deterioration-automobile/

It seems fair to propose that if an engine is not running then heat, shear, fuel and wear metal contamination, and blow by should all be reduced.
Also that oxidation should be reduced as likely aided by heat and mixing of oil with air as eg. drawn through PCV system
Moisture is probably a bet either way - some moisture could permeate through open valves, up exhaust, but there is probably usually some present from blow by and PCV when engine is running - and a good freeway run should boil it off
Additive depletion could include alkaline additives and VI enhances - probably reduced consumption if not running.

Interestingly its not recommended to change diff oil on a regular basis even though the diff has a breather so moisture could get it and condense...

Or if an oil packet was opened for a year, cap left on but not tight, so air but not dust could get in, would the oil go off?

At the end of the day I'd probably be more worried about seals drying out, eg. AC compressor, than the oil 'going off'. Would be good if you could get someone to start and run it for 10 mins every month or two while you are away... That said I suppose if you get the oil on sale for $6 per litre its only going to cost about $30 to drop and refill it. Presumably the filter wouldn't need to be changed unless these 'go off' as well....

 

[[paradox]]

At the end of the day I'd probably be more worried about seals drying out, eg. AC compressor, than the oil 'going off'. Would be good if you could get someone to start and run it for 10 mins every month or two while you are away...

im with you on this one

 

[Skylarking]

A thread dig but came across this video today which highlights the importance of doing an oil change between the scheduled service oil changes. The guy within the video tries to make the point how more frequent oil changes are a cost effective insurance against engine rebuilds.

It's long and its about a toyota but the importance of more frequent oil, coolant and trans fluid changes are made.

 

[Skylarking]

And another video which may answer the question whether oil goes bad sitting on a shelf…