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Discussion Starter #1
Hey all

I just replaced the Michelin primacy rfts that came with my car with some pilot a/s 3+. The ride quality is MUCH better, but the steering suddenly feels numb and somewhat floaty. I’m surprised, given the reviews on this tire and the fact that I was originally running grand touring tires. Anyone with similar experience? Perhaps playing with tire pressures would help? Help!



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Breaking in the Pony
2019 Mustang GT / 2005 Toyota Tacoma
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I replaced the Pirelli RFTs on my M235 with a set of Pilot A/S 3+ and experienced none of that. Still not sure if I preferred the Michelins to the Conti DWS tires I ran on my 335, though.
 

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Couple questions: Are they the same size as OEM or different?

Have the same set on my 335 but I went +1, +1 and I have no problems with them. Suggest you check your tire pressures cold with a known good gauge.
 

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Discussion Starter #4
Good point. I upsized from the standard square setup to the oem staggered one. Maybe the tread just needs some time to break in. The rubber is definitely a little greasy as well.


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Discussion Starter #5
What tire pressures do you recommend? Obvi the door jam’s 33/41 is for RFTs


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My 535i's door jamb decal says 35 PSI front and 39 PSI rear. I swapped out the OE RFT's for non-RFT Micheline PSS's, and through an iterative process I've adjusted the pressures to achieve even tire wear: 38 PSI front and 40 PSI rear, measured when the car is cold and at the morning low temperature. I rarely carry anybody in the backseat and rarely carry much stuff in the trunk. Over the years, I've found that Michelin non-RFT's need less pressure to wear evenly than RFT's or other brands of non-RFT's.

I measure tread depths in all four circumferential channels when the tires are new.

I guess at initial pressures, usually 5% to 10% over the decal pressures (measured cold in the early morning). I maintain those pressures for an entire rotation stint.

Prior to the next rotation, I measure the tread depths in all four circumferential channels on each tire again, and calculate the wear in each channel of each tire.

I adjust the pressures for the next rotation stint according to the wear patterns. The wear patterns can also indicate when I need an alignment.

My rotation stints for all-season tires are equal to one eighth of the expected life of the tires. That puts each tire in each corner twice. In theory, the wear patterns on all four tires will be just about identical at the tires' end of life. I've found that summer, high performance tires wear faster when they're new. So, I make the second and subsequent rotation stints the expected tire life divided by 7.5. The first rotation stint will be half of what the subsequent one are.

Rotating your tires, and maintain the same rolling diameter between the front and back tires will lessen the slipping (and wear) of the clutches in your xDrvie transfer case.
 

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Discussion Starter #7
That’s super helpful—and detailed. Thank you so much!


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I replaced the RFT Bridgestones with the A/S3+ and I'm very happy with the handling. I have the OEM Sport sizes inflated to the door sill recommendation PSI. I found the ride is better than the RFT with no loss in handling.
 

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Discussion Starter #9
Thanks very much. The turn in is crisp, but overall steering feel is diminished. Might be my imagination.


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