Teutonic, I do not know what your problem here is. We do not have the luxury of using 504 oils in the US. They are not approved. The approved oils are 502. But the difference is mainly sulfur and ash levels for Euro environmental standards with 504 oils. I will post some of my data, but not all of it, since I've spent around $4000 for consulting on oil for this engine. Yes, I do have access to a world-class oil tribologist and racing oil formulators, people who have worked for major racing teams, engine designers and oil suppliers. My tribologist is Terry Dyson
www.dysonanalysis.com. If you want your oil tested, send it to him in the US.
Actually, ring seal and tolerance of fuel wash down is quite dependent upon the molecular structure of the oil and it's additive chemistry. And fuel dilution and flashpoint measurements are almost totally dependent upon the quality of the seal. The 502 and 504 standards perform live engine tests on the 1.8T engine, which is manifold injected and not direct injected like ours is. There lies a big difference. Now, you in the UK may not have as large a problem, since your engines do run in stratified mode, which will cook off any diluted oil, but that remains to be seen. In the US we have a problem. Here are measurements of flashpoint and 100C viscosity across multiple oils and multiple RS4 engines over the last year. If you know anything about oil, you will recognize that the out of the bottle flash point for most modern synthetics is about 400 F, and that when the oil reaches flashpoint it begins to volatize, which means that it will either be vented by crankcase ventilation or will be burned off in the combustion chamber, leaving behind some level of deposits. You can see from our measurements that flashpoint dangerously reduces to extremely low levels, and the oil shears down to a lower weight. (These are all 5w-40 or 0w-40 oils here in the US). Wear also tracks fuel dilution, since fuel in the oil tends to breakdown exposed metal, and causes short term acidity in the oil, before the oil additive package can correct, which takes time. You can also see the latest samples on my test oils, which are much more fuel dilute and shear stable.
There are also some short mileage test sample runs, which were used to see how fast the oil dilutes under different operating environments, including cruising, high throttle, WOT and Idle. Because of the fuel dilute problem and the excessive wear it begins to cause, oil has not stayed in my engine for more than 3500 miles. We do have a sample on Castrol that stayed in an owners engine for 7000 miles. It was severely degraded and the engine had begun consuming oil at a rate of 1 Qt per 500 miles. After the change, no consumption. I personally have not seen any oil consumption after the 1st 2000 miles. But, I do not let my oil degrade. With my newly formulated oil, I hope that I can go much longer between changes. However, tribological analysis will guide and direct that decision.
Mileage Mileage on Oil Oil Viscosity 100C cSt Flashpoint
610 610 Factory Oil 10.6 295
1808 1808 Factory Oil 9.4 315
2030 2030 Factory Oil 10.4 390
2130 2130 Factory Oil 10.8 320
2201 1591 Motul 8100 E-tech 0w-40 11.7 335
3067 3067 Factory Oil 10.8 320
3134 1326 Elf Excellium LDX 5W-40 12.1 320
5005 2250 Amsoil 5W40 11.4 340
5298 3490 Elf Excellium LDX 5W-40 11.1 415
5633 2487 Castrol Syntec 5W-40 11.5 250
7242 4175 Motul Xcess 5W-40 11.7 275
7770 2600 Motul 8100 5W40 9.7 220
8225 3000 Amsoil 5W40 11.4 300
8233 2935 Motul 8100 E-tech 0w-40 11.3 310
8815 143 Motul 8100 E-tech 0w-40 12.4 365
8866 51.1 Motul 8100 E-tech 0w-40 12.6 345
8916 50 Motul 8100 E-tech 0w-40 12.2 280
8916 40 min Motul 8100 E-tech 0w-40 12.4 280
9510 537 Motul 8100 E-tech 0w-40 11.9 270
10059 1086 Motul 8100 E-tech 0w-40 12.4 280
10606 1633 Motul 8100 E-tech 0w-40 11.6 270
11485 3053 Amsoil 5W40 11.4 300
11896 2923 Motul 8100 E-tech 0w-40 9.9 235
12100 7000 Castrol Syntec 5W-40 10.2 230
12803 2803 Castrol Syntec 5W-40 11.9 265
14779 1562 Test oil 1 (10W-30) 10.9 340
15738 672 Test oil 2 (5W-40) 13.6 360
16554 1488 Test oil 2(5W-40) 13.8 345