Always LOP. Generally lower CHT too.

I have a question.

I got some service test time in a completive pressurized single (names withheld to protect the guilty), and found that on real hot days (100+ deg F day at ground level), the climb was considerably worse than book, which itself was lower than a standard day. In a climb to 18,000 feet, the climb rate would actually increase as I climbed.

Asked around to people that designed and tested the plane and never got a good answer.

Have you seen anything like that?

I did a little flight aware stalking. He still owns it and flys it 150-200 hours. I would love to hear what his experience has been.

I met a guy last summer with a 2008 Matrix he bought new, he thought he would have it a few years and sell it and buy another new airplane. 16 years later still loves it and thinks it might be his last airplane.