I wonder if it is more an issue with what little unused memory left getting filled up (like storing textures in a cache) than a leak. What resolution are you running? lowering it should require less memory to run.
Sorry I missed your reply earlier in this thread Wirenut, so let me answer you now. I'm running Forza 7 at 1080p on my PC when I see what I'm calling the memory leak phenomenon. If I back the res down to 720p from launch, I don't see the problem, but the graphics are unacceptable at that res, especially when I'm used to running the game at 4k 60 FPS on my XBox One X.
I'll probably eventually buy a 6 or 8 GB Geforce GTX 1070, especially now that I've gotten hooked into iracing again after a three year hiatus. That Fox Sports 1 broadcast of the NASCAR eracing using iracing last week at Homestead pulled me in. I can run iracing at 4K on my system even with the 3 GB 1060 and it averages in the low to mid 70s in frame rate. Unfortunately, it tends to drop into the 50s at irregular yet infrequent intervals. I'm thinking the additional processing power and expanded memory of a 6 GB 1070 would help with this.
iracing has good force feedback support, but it's not up to the superb force feedback support Forza 7 affords my Thrustmaster TX Leather wheel. I'd love to be able to run both Forza 7 and iracing with confidence and no fear of 'memory leakage'.