Only one test of each tire? Do five tests of each where you let air out and re-pump to pressure so we can see how repeatable your test is. For all I know, the difference you see between tires could be equal to what you would see using the same one in two separate tests.
best way to present the data: redo each one 5 times, average the 5 trials for each tire, and then find the standard error, plot it in excel with errors bars, then find if the difference is statistically significant using t-test.
Here's actual rides on strava https://www.strava.com/activities/256898212 and https://www.strava.com/activities/230440005
I'm way too lazy to re-pump and also no longer have working set of Open Corsas anyway.
After putting about 500 miles on Grand Prix 4000S I can tell that those extra 10W (assuming they for real) did not made me go noticeably faster (or slower for that matter).
So far I'm very pleased with 4000S - they will last longer for sure, seems to have superior protection from road debris and much better grip in wet.
They do have bumpier ride thou - hard to argue with that