I really like the YT series and may in fact buy one but One thing I don't like is that they are normally aspirated ( as is the T494 from what I could find). I am only at 3500 ft and would probably see a 10% power loss, at 7000 it would likely be double)
A turbo loses about 1% per thousand, NA about 3%.
If my numbers are wrong, someone please correct me.
I also would look at the ex-Branson tractors- the xx20 series. Along with the build they have a 4 range transmission which folks seem to love. They are supposed to be a tiny bit more austere. I have read that a regen helps in cold climates.The comparable one to the T494 is the 4820, which is also NA. Moving up to the 5520 gets you a turbo.
Just for fun I did some quick and dirty math using 1%/1000 loss and 3%/1000 loss.
T494 pto hp 37.2 becomes 29 at 7000ft
4820 pto hp 38.4 becomes 30 at 7000ft
5520 pto hp 44 becomes 41 at 7000ft
I live at 7000+ feet and have had tractors for 50 years. There is a lot of misinformation about turbos.
Right now some of our tractors and cars have turbos and others don't .
Yes, those numbers are real, but they don't tell you the real story because those are max HP at wide open throttle. Most of us don't run any machine wide open.
So if you are working at anything less than wide open throttle, the the other way to increase HP at high altitude is to just increase the RPMs you are working at. Open the throttle 10% for the same result without all the noise, wear, and inefficiency.
Frankly, I rarely work my tractor with the throttle wide open anyway. Very rarely does a job absolutely require full throttle to do. About the only time I really use full throttle is when I'm in top road gear on the paved road, going to town for fuel, come to a long uphill, and am too lazy to downshift. Tractors tend to be overgeared in road gear anyway. If I have to use full throttle for working, I should have bought more engine displacement hp to start with.
So I'd say buy enough HP that you have HP & throttle to spare, and then whether the engine makes that spare HP with a turbo or through extra displacement or by a combination of the two doesn't matter.
rScotty