Hello guys. I'm considering changing the rims on a 2850DT (european open station version) to lower it. The goal is so that I can use it on a fig orchard beneath the trees. I searched around and it seems that rolling ratio is what matters, but my mechanic consulted with someone that has the original service manuals and says that I shouldn't change the rear tires bellow 16.9R30. I told him that I searched a lot and that practically everywhere is mentioned that rolling ratio is what matters but he insists that I shouldn't do it because of the binary in the front axis differential, which he says is the reason the technical manual mentions 16.9R30 as minimum. But I'm thinking to myself, to achieve the max binary (I think he means the high torque on the gears when pulling) I would have to be loading the tractor with a lot of weight, but I'm not gonna use it for tilling anyway, otherwise I would destroy and tree's roots! Just need to do some mulching under the trees to avoid too much weeds and stuff. Heck for what I'm gonna use it I don't even need the 4wd engaged, in which case it doesn't matter.. It's a risk if I forget and engage the 4wd, but it shouldn't be a probablem if not used for a long time.
But I want to be sure! Can anyone share their experiences ? I know in the US you guys use tractors mostly for extensive agriculture so probably only a few orchard farmers in here...