Engine: D5244: Oil Requirements

[D5meister]

sure its a trade off, the book is a guide.

Volvo in cambridge used to put 10W40 shell helix semi synth in at all services until I had an out-of-character at them.

" Nobody else has complained sir " wasnt good enough.

I supplied " volvo service oil " in unmarked containers from the start.


It was 0W30 mobil 1


My dad always topped up engines as needed and never changes oil. He used reclaimed oils 20W 50 sludge and somehow got by in his tatty cars.


Modern engines need flow thru hydraulic tappets otherwise they stick and then clack and chew up. You only get that flow with thinner oils.

Main bearings are all cut on automated machinery and the tolerances are almost gas tight, again they can take water thin oils.


If you but 15W40 in a new modern engine the massive molecule chains open the engine - irreversibly wearing it to fit the thick oil.

Using thin oil subsequenly would not provide not provide stable long lasting lube - I was told from a shell or Castrol oil tech expert.

[Clan]

Originally Posted by D5meister

sure its a trade off, the book is a guide.

Volvo in cambridge used to put 10W40 shell helix semi synth in at all services until I had an out-of-character at them.

" Nobody else has complained sir " wasnt good enough.

I supplied " volvo service oil " in unmarked containers from the start.


It was 0W30 mobil 1


My dad always topped up engines as needed and never changes oil. He used reclaimed oils 20W 50 sludge and somehow got by in his tatty cars.


Modern engines need flow thru hydraulic tappets otherwise they stick and then clack and chew up. You only get that flow with thinner oils.

Main bearings are all cut on automated machinery and the tolerances are almost gas tight, again they can take water thin oils.


If you but 15W40 in a new modern engine the massive molecule chains open the engine - irreversibly wearing it to fit the thick oil.

Using thin oil subsequenly would not provide not provide stable long lasting lube - I was told from a shell or Castrol oil tech expert.

Indeed , in fact each shell upper and lower are individually selected for each individual engine , and upper shells are different material to lower shells . All to make sure 0w/30 or 0w/20 works as intended . the bearing shell numbers are stamped on the blocks , this goes right back to 1990 when these alloy engines were first introduced on the 960 .

[Leyburn]

I've been running extended oil change intervals for several decades on a variety of vehicles! The key is no short journeys, don't let the engine idle from cold for more than 30 seconds or so and don't cook the oil on turbo cars.

[MarvinMitt]

Originally Posted by Leyburn

I've been running extended oil change intervals for several decades on a variety of vehicles! The key is no short journeys, don't let the engine idle from cold for more than 30 seconds or so and don't cook the oil on turbo cars.

I've been practicing the idling for 10 secs before stoping the engine to let the oil flow cool the turbo down a bit, is that what you mean by latter?
And what do you mean by "don't let the engine idle from cold for more than 30 seconds"?

Thanks

[Shinsplintz 101]

Can I just ask why? Even at 5K service intervals fresh oil is a drop in the ocean compared to the cost of the fuel used incovering those miles. Filters are a tenner. Why risk it? It costs me £45 & half an hour of my time every 3 months to keep the oil fresh as a daisy including a good chance to have a poke around under the car to check for signs of wear & tear on other items, such as suspension & brakes.

Each to their own, but the extended service life of 18k miles seems madness to me. An awful lot can go south over that distance & you limit the opportunity for proactive maintenance that shorter service intervals give you.

Leaving the car tick over for a little while before shutting down is always advisable in a turbo car after a spirited drive, letting the turbo cool whilst the oil is still flowing to avoid cooking it, as mentioned above.

[Leyburn]

Originally Posted by MarvinMitt

I've been practicing the idling for 10 secs before stoping the engine to let the oil flow cool the turbo down a bit, is that what you mean by latter?
And what do you mean by "don't let the engine idle from cold for more than 30 seconds"?

Thanks

Late reply ....

Turbo engines can overheat the engine oil if switched off immediately following extended operation at higher rpm; on the road this can occur at a motorway fuel stop. Overheated (cooked) engine oil = sludge

An engine warms up quicker if it's under load and working at higher rpm rather than idling. The longer an engine takes to get to operating temperature the greater the level of wear.