I spent time getting used to the car and completing the break-in process. After the oil change I started to become to experience the classic mustang wheel hop the new S550 IRS suffers from.
Mile 573: Break-in Oil Change
It was time to change the engine oil with the break-in complete. I used Mobil 1 5w-20 full synthetic oil and a Mobil 1 M1- 212 extended performance oil filter.
Mile 728: Mustang Wheel Hop
It’s a real problem for this platform. The new IRS suspension is great in the twisties, but man that wheel hop just kills performance. I decided to pick up some Steeda IRS Subframe Braces from American Muscle and throw them on the car. The parts arrived quickly and I did the install in my garage. Overall it wasn’t super difficult to align, but some effort to get everything to line up was involved. There are some steps in the instructions you can follow if you can’t make the bolts match up. I didn’t have to do that in my case. Keep the bolts loose until you’re ready to tighten them all down at the same time.