LOL, back to the original topic, yep the Ford Probes and Mazda MX6 use the same engines. The GT (which I drove for some 6 or 7 years) has the 2.5 L V6, called the KL-ZE (I might be mistaken) in Japan, and the 2.0 L found in regular Probes are supposed to be a lower compression (and slightly more dated, of course) version of the FS that we have in the MP3.
And yes, it was very difficult to make power in the Probe GT engine, at least. I went bolt-on crazy for a while, and to be honest, I barely felt any difference. For one, it was a heavier car than the MP3 (slightly), and two, it had wider rubber (stock 225 50 16, I had 235 45 17 on Momo Arrows). Maybe there were some horses, but it was hard to feel it.
Bad thing is, there were serious durability issues with the V6 engine, and that's why I got the MP3 now. Good thing is, the I4 didn't have those same issues (at least that I know of).