pacino13211

10K without changing the oil is just too much for me. I dont care what the owners manual says. I change my oil every 4-5k miles. Summer time i use 5w40 full syn. and winter time i use 5w20 full syn. At first i thought 5w20 is a little thin but i live in upstate NY and winters can be cold and the 5w20 really helps on cold starts. I remember the first winter i used 5w40, everytime i would start it cold the engine would rattle for a about 5 seconds but not with 5w20. Just some food for thought. Also another thing i noticed everytime i change my oil i put 8.5 quarts of oil and its a little high when you measure it cold but after the engine runs for a while and i let it cool of for half an hour then measure the oil its perfect. Weird?

bmwm750

5W20 is a bit thin for a German motor. I know all the Japanese and American cars are going to the water-thin spec, but I wouldn't run it in a 4.2.

Plenty of us have done oil analysis, and 10k oil intervals are perfectly fine.

mishar

5W20 and 5W40 should have same viscosity when they are cold, that of SAE5 oil. When they are on a working temperature 5W20 has a viscosity of a SAE20 oil and 5W40 of a SAE40.

For our engines 0W40 is the best. 0W for cold starts and 40 for a bit oldish regular engines.

volvopentaman

No idea with 4-5k intervals with todays oils. In the past days with MINERAL oils it was a good thing.

Tough to admit, the 10-20k longlife interval is probably an idea from the marketing people and threehuggers to save our oil reserves.

I had a volvo 340DL 1986 manufactured in Holland, not sold in the US, very common car in europe in the 80's and 90's, with renault's 1,4L engine, commonly used in renault 5 and 21. The engine was prone to camshaft failure (OHV engine). Had it in our family almost since the car was new, oil change with shell mineral 10w40 every 3-5kMLS and mostly city driving. Took the engine apart around 200kMLS (most of these engines failed at 80-150kMLS due to camshaft) and the camshaft wasn't worn at all, only 3 lifters needed to be replaced.

I have also an S90 volvo 1998 model with 3,0L 204hp I6 engine, DOHC, it has around 180kMLS on the clock, mostly highway driving. Oil change every 9kMLS according to the service booklet. Engine runs like a clock. Had a friends volvo with same engine with same miles. That engine hadn't probably been treated as well, as the car wasn't as powerful as mine, even tough both were with the same transmission and HP rating, and my friend's car was 300lbs lighter. The compression test revealed the problem, mine had 17bar and my friends 12bar per cylinder AFTER cyl.head overhaul. The engine was probably badly treated.

My A8 W12 has now around 150kMLS on the clock, oil change with longlife interval the first 4-5 times, so 90kMLS with 4-5 oil changes, and after that 9-12k interval. Engine feels to have all her HP, and no oil consumption. Always treated with Castrol 5W30 longlife 504/507.00.

I too think that 5W20 is a bit thin when the engine is hot, especially in summer months. If i could without a problem start mine with 5w30 longlife oil at -20degrees celsius, i don't think there is a need for a thinner oil.

Thinner oil will leak easier, and will be more consumed than thicker, and won't lubricate as good as thicker, when the oil-film will be too thin.

Bangerla

There are some changes in the thinking about oil. For many people it was all about oil pressure, and keeping a reasonably high oil pressure. Lately the thinking about oil is shifting, and that oil flow is more important than oil pressure. This is why many of the newer engines are going to a lighter oil. With todays engine tolerances you need a lighter weight oil, or you will have excessive pressure. I rebuilt a Porsche engine, and have a very tight, exact fit on everything, needless to say its hard to get a thicker oil through a tight engine. That engine runs 0 weight oil, just to keep the pressures down. By running a heavy weight oil, you can actually do more damage than good, if the engine was not designed for it.