Actually the Navy tested a FW-190A5-U8 VRS a F4U-1(no water injection) and F6F-3 and found that the FW-190 and F6F-3 were equal at sea level at a top speed of 334 at sea level and the F4U-1 was 29MPH faster 363mph at sea level. At 25,000ft top speeds attained were F6F-3 at 391mph, F4U-1 at 403Mph and the Fw-190A-5 at 410Mph.
Test were also performed between the P-51A and the Fw-190A(no further designation given)
in 1942. Speed results are the Fw-190 was 2mph faster from sea level to 5000ft. The P51A was between 5 and 15Mph faster up to 15,000ft. This test was performed by the RAF.
My source is "FW-190 Workhorse of the Luftwaffe" by the Smithsonian Institute Press. Take from this what you will but I don't think "nothing can outrun the FW-190 at low altitude" is an accurate statement.
I also don't think the AH F4U-1D can hit 363MPH at sea level either. Wine, Wine, Wine, Wine, Wine!
Thanx
F4UDOA