Mobil 1 - checked oil on friday and it was absolutely empty? afetr 7500 miles too? Grp N filter arrived so shoved it in the box too! Wow - noticable differnce - revs even freer now - considerinng its 1/4 depth of the oroginal I imagine it should be much freer flowing! Pick up in 5th is immense now coz there was a bit of a flat spot once changing to 5th from the limiet in 4th!