I recently replaced the OEM Michelin tires on my 2010 SRX at 40K miles. The tires were about half-worn and had always rodden fine and wore smoothly. The new tires are the identical Michelins. I immediately noticed a vibration in the car when cruising at 50mph and above. The vibration seemed to come and go. I returned to the tire dealer and had them rebalance the tires. The vibration persists. I've now been able to determine that the vibration only occurs when there is a load on the drivetrain, like going up a grade--even a slight one. I can feel the vibration in sixth or fifth gear, the car running in cruise control. The vibration stops when the extra load is gone. I talked with the local GM service manager and he said it might help to reflash the tranny/engine module(s), but we're not sure. It does seem that it could be an issue with transmission/torque converter not locking properly under these mild load situations. I'm wondering if a slight change in the diameter of the new tires could cause an issue? In any event, the vibration began with the tire change and has now been there for 2k miles. I'd like to know if anyone has had and, hopefully, solved a similar issue. Any suggestions would be appreciated. Thanks.