[Torinalth]

Hey everyone,

My previous post probably wasn't the best title to be searchable so I made a new one now that I've completed the process. As of this morning I'm running 275/40-20 Michelin Pilot Sport 4s at all 4 corners. I'm using the stock 20" 699 rear wheels (20x9.5) and picked up 2x 699 replica 20x9.5" wheels online. I had to use spacers to make them fit.

I tested the process by running the rear wheels on the front of the car for a month to make sure everything was great and accounted for. Side note, I got a lot better turning performance with just this process, but the back broke free too easy going hard on power in turns. for fitment I tried 15mm spacers first and though it did barely clear, on tight turns the tire would get close enough to drag the strut on the drivers side. so this will be alignment dependent. I didn't want to take a chance on needing more camber and then rubbing, so I ended up changing out to 18mm spacers. Everything clears on all 4 corners, no rubbing anywhere.

So this morning I finally got the Michelins mounted and started driving. Quite a difference over the alenza RFT from the factory, as to be expected. The ride is much smoother. Turn in is greatly improved with the Michelins, even over the moderate improvement of running the rear wheels on the front. I have not had a chance to really beat on them to see where they fall short but so far I'm pleased at the improvement and the ability to rotate tires. Only downside is now I do get a little spray down the side of the car at the lower parts of the vehicle, so i'll need to do some sort of splash guard, but that's the only drawback so far.

CLIFFS: 18mm spacers on all 4 corners will allow you to run stock 20x9.5-43 rear wheels on all 4 corners with 275/40-20 tires.

[MADBMWX5MC]

Would love to see pics...

[Torinalth]

honestly not that impressive to see, but I'll grab some in the AM when light.

[MADBMWX5MC]

You know forums...pics or never happened....

[Torinalth]

[Torinalth]

Since I really hadn't talked about the difference its made, why not do that now that I've gotten some good seat time behind them. going square setup and going to the Michelin PS4s has made a bigger difference than I can honestly believe. The turn in is so much crisper now, nearly instant movement of the x3 with your steering input but still somehow delivering a smoother ride than the stock Alenzas. Overall grip is unbelievable. I was taking turns on Thursday in the wet that I was forced to take slower in the dry on the Alenzas. The biggest bonus is the feel of the PS4s at the limit, you can easily feel when you are at about 80% of tire grip and it just starts to let you know that its coming closer to not being able to perform before it does end up sliding. With the Alenzas you'd just start to snowplow without much warning. Not only does the car rotate much more freely and resist understeer to a much greater extent (square setup bonus), its so predictable now that it's just a point and shoot feel that I used to get in my old WRX wagon I had modded to hell.

Down side is the sheer price of the tires. They are top in their category and for the treadwear rating they are far and away the most expensive rubber you can get before moving into a track oriented tire. I think it's worth it though. An ancillary downside is the need to reduce body roll now. With how wide the tires are now in the front I'm not sure how much I can lower the car without it rubbing the fender, but i'd kill for some swaybars to flatten the roll degree.

[MADBMWX5MC]

Hey, I appreciate your comments and effort. I think the another win is the ability to rotate tires...thanks, partner.

[hoss_wagon]

Sorry for bringing back an old thread. Did you stick with the 275/40/20 square set-up? How did you like it over the long rung? Did you notice if the wider stance wound up throwing more road debris/dirt down the side of your X3. I'm interested in doing a similar set-up with aftermarket wheels. Thanks!

[Chief Orman]

Originally Posted by hoss_wagon

Sorry for bringing back an old thread. Did you stick with the 275/40/20 square set-up? How did you like it over the long rung? Did you notice if the wider stance wound up throwing more road debris/dirt down the side of your X3. I'm interested in doing a similar set-up with aftermarket wheels. Thanks!

Anyone do this with 21 inch rims?

[Ldstern]

Originally Posted by Torinalth

Since I really hadn't talked about the difference its made, why not do that now that I've gotten some good seat time behind them. going square setup and going to the Michelin PS4s has made a bigger difference than I can honestly believe. The turn in is so much crisper now, nearly instant movement of the x3 with your steering input but still somehow delivering a smoother ride than the stock Alenzas. Overall grip is unbelievable. I was taking turns on Thursday in the wet that I was forced to take slower in the dry on the Alenzas. The biggest bonus is the feel of the PS4s at the limit, you can easily feel when you are at about 80% of tire grip and it just starts to let you know that its coming closer to not being able to perform before it does end up sliding. With the Alenzas you'd just start to snowplow without much warning. Not only does the car rotate much more freely and resist understeer to a much greater extent (square setup bonus), its so predictable now that it's just a point and shoot feel that I used to get in my old WRX wagon I had modded to hell.

Down side is the sheer price of the tires. They are top in their category and for the treadwear rating they are far and away the most expensive rubber you can get before moving into a track oriented tire. I think it's worth it though. An ancillary downside is the need to reduce body roll now. With how wide the tires are now in the front I'm not sure how much I can lower the car without it rubbing the fender, but i'd kill for some swaybars to flatten the roll degree.

Any difference in steering feel and gas mileage?

[n3g4tiv3f33db4ck]

I would love to know some long term results as well. Thank you for the original post!

[Grand Moff Alpina]

Wow, now this is a thread I'm interested in! Thanks to whoever bumped this back up.

My big question would be whether OP found a solution to reduce body roll a bit.

[hooligan_G01]

Originally Posted by Chief Orman

Anyone do this with 21 inch rims?

Don't see why 21s wouldn't also work, assuming same width and effective offset, if you went with 275/35/21 tires.