0W30 or 5W30

[skyship007]

SAE figures like 5w40 cover a range of possible viscosity figures, so one issue with using a 5w30 rather than an 0w30 is that you might be using a thinner oil at high temps, as most versions of Castrol Edge are near the top of the 30 range.

The other difference is that the viscosity figures quoted for most oils are at 2 temperatures only and viscosity is a curve, so if the figures look the same a 5w30 is in fact slightly thicker when cold or hot than a 0w30. An 0w30 is thinner when cold than an 0w40 in most cases, so using SAE groups is a bit confusing.

The difference between the old single SAE figure straight oils and modern multigrades is achieved by the use of viscosity improver additives, BUT they do slightly weaken the chemical composition of the oil, so in hot desert operations Volvo recommend using a 15w40 full synthetic, both because it is a thicker more high temp shear resistant type of oil and because of ultra fine dust contamination is less of an issue with thicker oils.
The opposite is true in the Artic when you do need the 0w part of an 0w30!

The Germans are very fussy and the chaps I know who work in the local oil lab (ZF) nearly all use 5w40 in the diesels once they are out of warranty. One chap is a bit of an oil fanatic and uses Amsoil 15w40 (One of only a few full synthetic 15w40's made) in summer and LM Synthoil 0w20 plus a can of Ceratec in winter.

Design specs as regards engine oil are still in the low 40's for most non hybrid diesels and mid 30's for most non race petrol engines when new. Most car companies chase fuel economy, so they recommend a grade lower, as oil viscosity does effect fuel economy, both in the engine and in the gearbox. Very few car companies are interested in how long the main block of an engine lasts, as long as it does not fail within the warranty period they will use a cheap thin oil and oil change intervals that are often too long at their dealers.

If you can reduce wear to a minimum it reduces oil consumption in most cases and it's oil burning that ultimately kills a DPF, so oddly enough although a few of my friends are unlucky enough to own diesels with a DPF, they use Acea A3/B4 cat oils in an attempt to keep that wear to a minimum.

[Munro83]

I've wondered about the start stop technology causing avoidable wear, can you switch it off via remap?

[skyship007]

Originally Posted by Munro83

I've wondered about the start stop technology causing avoidable wear, can you switch it off via remap?

Stop start is good news not bad. In fact it can reduce engine wear if you are based in a big city.
Intial start up wear is only a factor once the enginhe starts to cool down and the oil drips down away from the cylinder walls and that takes a while. The reduction in idle time reduces top end deposits, so it is good news for valve guide oil seals and the rings in particular.

[skyship007]

Originally Posted by JimG

⬆️⬆️⬆️ f. U. C. H. S.⬆️⬆️⬆️

Good company who are a major shareholder in Liqui Moly. Their main business is the refining and production of base stocks for engine oil mixers, but they also produce good commercial engine oils, some race oils and factory fill special mixes.

They do sell a cheap 10w40 (A3/B4) in the UK, although if you like long service intervals or a hot set of turbo bearings, it's only as good as Castrol GTX or Halfrauds 10w40.

[GrahamBrown1]

After all people have said I bought my Volvo S60 2007 D5 with 98,000 miles with Volvo history so I assume it only ever had the Volvo 0w30 oil. I sold it at around 144k and only ever used the castrol 0w30 A5 B5. The engine still quite and showed no signs of wear or oil consumption. I'm not an oil scientist but volvos recommendation seemed to work Fine in my car even if it was a little expensive.

[Clan]

Originally Posted by GrahamBrown1

After all people have said I bought my Volvo S60 2007 D5 with 98,000 miles with Volvo history so I assume it only ever had the Volvo 0w30 oil. I sold it at around 144k and only ever used the castrol 0w30 A5 B5. The engine still quite and showed no signs of wear or oil consumption. I'm not an oil scientist but volvos recommendation seemed to work Fine in my car even if it was a little expensive.

That is quite typical , Volvo work with Castrol and it works , nobody knows better than them ...

[5cilinder]

Originally Posted by skyship007

SAE figures like 5w40 cover a range of possible viscosity figures, so one issue with using a 5w30 rather than an 0w30 is that you might be using a thinner oil at high temps, as most versions of Castrol Edge are near the top of the 30 range.

The other difference is that the viscosity figures quoted for most oils are at 2 temperatures only and viscosity is a curve, so if the figures look the same a 5w30 is in fact slightly thicker when cold or hot than a 0w30. An 0w30 is thinner when cold than an 0w40 in most cases, so using SAE groups is a bit confusing.

The difference between the old single SAE figure straight oils and modern multigrades is achieved by the use of viscosity improver additives, BUT they do slightly weaken the chemical composition of the oil, so in hot desert operations Volvo recommend using a 15w40 full synthetic, both because it is a thicker more high temp shear resistant type of oil and because of ultra fine dust contamination is less of an issue with thicker oils.
The opposite is true in the Artic when you do need the 0w part of an 0w30!

The Germans are very fussy and the chaps I know who work in the local oil lab (ZF) nearly all use 5w40 in the diesels once they are out of warranty. One chap is a bit of an oil fanatic and uses Amsoil 15w40 (One of only a few full synthetic 15w40's made) in summer and LM Synthoil 0w20 plus a can of Ceratec in winter.

Design specs as regards engine oil are still in the low 40's for most non hybrid diesels and mid 30's for most non race petrol engines when new. Most car companies chase fuel economy, so they recommend a grade lower, as oil viscosity does effect fuel economy, both in the engine and in the gearbox. Very few car companies are interested in how long the main block of an engine lasts, as long as it does not fail within the warranty period they will use a cheap thin oil and oil change intervals that are often too long at their dealers.

If you can reduce wear to a minimum it reduces oil consumption in most cases and it's oil burning that ultimately kills a DPF, so oddly enough although a few of my friends are unlucky enough to own diesels with a DPF, they use Acea A3/B4 cat oils in an attempt to keep that wear to a minimum.

If you are realy hardcore antiwear
Use bypass filtration and pre pressurize your oil circuit before starting (standard practise in blue water shipping )

There are insta lube kits for carengines availlible also a bypass filtration filter isnt hard to implement

http://www.engineprelube.com/images/...cture-roll.pdf

https://www.youtube.com/watch?v=XCIE...youtu.bebe.com

[oilman]

Originally Posted by skyship007

Oils are made to a very specific price and only some of the OEM car oils contain enough anti wear additives to really reduce wear to a minimum and they are expensive (Dealer only in most cases) and restricted to mostly 0w30's.

Yes, oils are made to a price, but I do not know what you mean about the most wear reducing oils being dealership only and 0w-30. Dealership oils are often the own brand oils and like other own brand products, they are the budget option. 0w-30 oils are usually aimed at low emissions vehicles so will have reduced antiwear additives.

Cheers

Tim

[wilbydoughboy]

Volvo and Castrol go back a long way together and to break the 3 million miles proves it works.

[skyship007]

Originally Posted by 5cilinder

If you are realy hardcore antiwear
Use bypass filtration and pre pressurize your oil circuit before starting (standard practise in blue water shipping )

There are insta lube kits for carengines availlible also a bypass filtration filter isnt hard to implement

http://www.engineprelube.com/images/...cture-roll.pdf

https://www.youtube.com/watch?v=XCIE...youtu.bebe.com

You can fit some dual filter (One filter is an ultra fine and the other is a normal full flow) bypass systems to most diesels, BUT it will often mean moving the battery to the boot (Major Mod that must be declared to the insurance company) to allow use of that area for the 2 new oil filters.

Pre-lubing is a waste of time for smaller diesels, BUT pre-heating is not, especially in winter. A stick on heat pad helps reduce warm up time, but nothing beats a real coolant system heater that heats both oil and cylinder head. The system fitted to the emergency doctors cars in Germany (Plug in or diesel burners) allows redline RPM within seconds after a minus 25c start.
Oddly enough the cost of the extra electricity or fuel for pre-heaters is sometimes offset by better MPG figures, as the engine will get out of cold start rich burn into lean burn mode much faster.

For min wear figures it is essential to change the oil & filters only when the UOA sample indicates that the oil or filter (Or both) needs to be changed. This type of on-condition maintenance has been normal for big trucks and trains in the US for some years. Oddly enough some results can be very odd, as the UOA labs often finish up sending out more warning messages about bad air filters, or fuel injection system issues (Abnormal fuel contamination) than they do for such more normal block failures, like impending head gasket failures.
My own V40 1.9 likes long oil change intervals for example, but I would not copy that fact without getting your own used oil analysis done, as it might be the opposite.