Yeah, LOL, Mike was rather busy with those silly graphs during the last few days, it was fun to observe his progress. A genuie example of the 'credibility' of his site, he picked the worst performing 109s he could find, piled them together and compared them with hand-picked Spitfires.
As a matter fact, just look at a few examples what he compares :
109 G-1 Werknummer 14 026. Produced in February `42, ever since a testhack of Messerscmitt. The curves that he took are from a six week series of trials, that investigated the performance difference between DB 601E and 605A, primarly at ground level, and the radiator temperatures when built in the same airframe; altitude measurement we of secondary nature.
The plane went through 10 testflight, during which the engines were swapped 3 times, first the 601E was tested, then the 605A. One can imagine the aiframe`s condition by August 1942, when the 605A trials started... though I guess the most telling is the facts presented in the reports, ie. speeds achieved early in the trials with 601E and 605A in the end (both at Kampfleistung):
at 0m:
601 E : 514 km/h
605 A : 507 km/h
At critical altitude (VDH)
601 E : 622 km/h at 6000m
605 A : 627 km/h at 6100m
Now considering that the power outputs of 601E vs. 605A at 1.3ata:
601 E : 1200 PS at 0m, 1050 PS at 6000m. FTH : 4900m
605 A : 1310 PS at 0m, 1225 PS at 6000m. FTH : 5800m
Notice that the 601E powered 109G-1 gained
1100m due to the ram effect. By the time it was powered by the 605A, it only gained
300m .
Of course there are loads of other trials, each show the 109Gs rated altitudeplane`s as
7000m.etc.
Also one wonders, how did Miky miss the Rechlin tests of G-1... you know, the ones that states 403 mph at 23 000 ft at 1.3ata ? But he makes qoutes from the very same Rechlin page a bit below.

Would you want to guess why it isn`t presented ? Or why the Finnish, NIIVVS trials with 109G-2 at 1.3ata are 'missed' somehow?
Now let`s see the Spitties he chose..oh, fine selection, indeed :
Mk IX, BS 543 : The
prototype Mk IX LF tested well before the type went into service. Experimental engine, experimental propellor, none of which went into production in the same form.
409 mph is very nice, in fact, faster than the Mk VIIIs which were supposed to be faster than the Mk IXs.

But wait, there`s it little brother, BS 551, the HF
prototype from the same experiments the previous comes from. Just about the same relevance to the actual performance of the serial plane, just compare EN 524, the
serially produced HF Spit.
Mk IX, MA 648. Same trick by Mike, another prototype, this type with a experiment with the SU fuel pump. 411 mph, WOW, not bad for a prototype that
never saw any serviceNo, I wonder, why this classy selection misses good old JL 165, a 'standard Spitfire Mk IX LF' to qoute it`s perfomance trials, that managed to do... uhm...
388 mph.If someone wants, can make such interesting comparisons, Williams style, one can make it in a similair manner.
Say, take the G-2 tested by the NII VVS, and compare it to JL 165.

Yep, 413 mph done by the 109 at 23k ft, vs. a laughable 389 mph by the Mk IXLF. Hey Miky, isn`t that tough for an 1943 Spit not only to be outrun by a 109G by 25 mph at altitude, but it`s also
left behind by a two year older Bf 109F model?You know,
if I were Mike, and I would know what I knew what is coming, I would be really, REALLY quick in getting that page off the site, before perhaps it will be made an example about the mass number ofmanipulations going on that little spitty site.
A`la the Carson debunker articles.

I bet that would give some flavour to the site`s 'credibility', far and wide.

Seriously, the particular page can be hardly considered to be anything more than a byproduct of being a Spit zealot`s 109-envy, in which the extreme bias and the smell of primitive little tricks can be smelled a mile away. And if needed, I will prove that, line by line, and then make public for it, along with exposing every other silly little trick of that site, starting with the selective qouted Bf 109E evaluation, cutting half of the 109E vs. Spit I roll rate chart by Miky, or how he plays with holding back information about how exactly 'common' were the performance specs he posted for +25 lbs XIVs. All data needed for that is available to me and more. It`s rather boring to see those BS comparisons on Mike`s site, with the intent of misleading the public and serve the agenda.