Just did a quick drive and object inspector in the newest shaders patch: You didn't combine your trees into one object. Each tree is an individual object. Hence you are experiencing lower fps. You have to go section by section on the track and combine the trees into one object. For example, at the starting line, combine all the trees in the first 50 yards into one object. Now AC will render all those trees as one object. Second way to further optimize a track in AC is to do multiple .kn5 files. You have a model.ini file but you only have one .kn5 file. For example, select all the trees, delete everything else. Export and finish the trees in kseditor. Save name like Pinewood Trees. Next, do the road by it self. Save as like Pinewood Road, etc. Then in the model.ini you can add the all the layers together. AC will render the layers differently. There should be a guide on google search. This is just quick explanation. Don't forget to back up your files so that you can do different experimentation later.