Well as its part of the normal routine checks we do on our engines, transmissions,hydraulics etc offshore , i thought i would do it on my RS , as its supercharged and gets used and abused i thought it appropriate to get a
test done to see if there were any issues potentially , mainly fuel dilution in the sump was my concern as its under a lot more stress now and the fuel flow is greater and richer mixture on full power, so after about 4800 miles my Castrol Edge FST 5W 30 was drained and replaced... today i got the results back , good news ,all satisfactory , Nil fuel dilution, viscosity was unchanged insoluble matter (soot) was 0.3 % ( 2.5% max) 17 metals were tested for , my main worries were for iron( bore wear ,crank ,cams,valve gear/chains etc) Aluminium (pistons) copper ,lead and tin (bearings ) all were near 0 ppm , highest being iron at 12 ppm, 100ppm would be the min acceptable but 12 ppm was very good.Aluminium was 6 ppm (warnings at 30 ppm)
The only slight issue was the levels of silicon, at 16ppm (20 ppm is the warning point for silicon) which is normally due to sand /dust, which has entered the
oil via the inlet tract , so the K&N filter may be letting larger particles through than the paper ones do ,so i might go back to the paper filter and retest the
oil after a further 4800 miles to see the trend is the same or better , obviously if the
oil has done little miles , contaminants will not build up much , run it 10k or god forbid 20k longlife miles the numbers will be higher , so tests at similar intervals will show any issues , just thought i would share this with you guys , the V8 is tough no matter what you throw at it so long as you use good
oil 
Phantom black saloon ,PES M112 Supercharged 520ps/595nm K&N filter, 100 cell milltek cats,res valved milltek system. 8 and 10mm H&R spacers.H&R roll bars, "smoke chrome " alloy refurb. JHM Quickshifter, Bilstein B16 coilovers , uprated diff mount ,50/50 devils own WM kit so 1.4 litres/min in intake approx 10% more power and torque
1/4 mile 12.01 secs 123.5mph