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Front / Rear pressure in PSI for PS2 tyres on 18" rims

  • 34 / 34

    Votes: 6 9.2%
  • 34 / 35

    Votes: 3 4.6%
  • 34 / 36

    Votes: 4 6.2%
  • 34 / 37

    Votes: 2 3.1%
  • 36 / 36

    Votes: 4 6.2%
  • 36 / 37

    Votes: 0 0.0%
  • 36 / 38

    Votes: 9 13.8%
  • 36 / 39

    Votes: 2 3.1%
  • 38 / 38

    Votes: 3 4.6%
  • 38 / 39

    Votes: 1 1.5%
  • 38 / 40

    Votes: 9 13.8%
  • 38 / 41

    Votes: 3 4.6%
  • 40 / 40

    Votes: 5 7.7%
  • 40 / 41

    Votes: 0 0.0%
  • 40 / 42

    Votes: 1 1.5%
  • 40 / 43

    Votes: 0 0.0%
  • 42 / 42

    Votes: 3 4.6%
  • 42 / 43

    Votes: 0 0.0%
  • 42 / 44

    Votes: 0 0.0%
  • 42 / 45

    Votes: 0 0.0%
  • 44 / 44

    Votes: 2 3.1%
  • 44 / 45

    Votes: 0 0.0%
  • 44 / 46

    Votes: 0 0.0%
  • 44 / 47

    Votes: 0 0.0%
  • 44 / 48

    Votes: 6 9.2%
  • 44 / 49

    Votes: 0 0.0%
  • 45 / 45

    Votes: 0 0.0%
  • 45 / 46

    Votes: 1 1.5%
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    Votes: 0 0.0%
  • 45 / 48

    Votes: 0 0.0%
  • 45 / 49

    Votes: 0 0.0%
  • 45 / 50

    Votes: 1 1.5%
1 - 20 of 22 Posts

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Discussion Starter #1
E39 M5 with Michelin Pilot Sport 2 tyres on standard size 18" rims
(275-35/18 rear 245-40/18 front)

What tyre pressure combination do you use?

Please vote, and feel welcome to post your observations.

David

(48 PSI rear 44 PSI front)
 

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Im running PS1 with 38/ 35 and very happy with the results- no track time- just street driving- most of the time it is just regular driving with some aggressive maneuvers when the conditions allow.
 

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Nice idea, but your poll only has combos with lower pressures up front and higher in the rear. A lot of us run pressures the other way around to reduce understeer. This is especially important on people still running the stock staggered size setup. I use 35f/34r but don't qualify for your poll anyway since I run 4x275s on stock OEM rears.
 

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39/41. Tire wear looks very uniform. (with the exception of the outside of the fronts...:) )

Stock size; Dunnies (came with the car)

Prolly go to PS2 in 4x275 with next 're-rubbering'
 

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Your poll doesnt take into account people who run more air up front. 40 front, 39 rear.
 

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I voted for 38/40. I think the car feels best at that. However, at that pressure I've gotten the middle to wear faster so 36/39 might be closer to optimal wear. On the track I do 40/40 or 42/42, not letting it exceed 46 or so hot.
 

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34/36 gives me a comfortable ride with great handling, all four tires wear evenly
 

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Discussion Starter #9
Thanks for the great input, everyone!

You see, I used to have Dunlop SP 9000 275-35/18 and 235-40/18 on stock rims on the car. Pressures were at the lower recomended numbers per the door sticker.

Tyre wear was dominated by the outsides of the front wheels. I assumed this was due to rolling the sidewalls when cornering.

I put Michelin PS2s 275-35/18 245-40/18 on a while ago. I set the presures to the upper recomended numbers per the door sticker (44/48 PSI), hoping this would limit front wheel outside tyre wear.

Handling is good, but I will make some experiments based on the input from this thread.

Does anyone have experience of the corelation between pressures and outside wear?

David
 

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Discussion Starter #10
Does anyone have experience of the corelation between pressures and outside wear, please?

David
 

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35F-33R


More pressure more wear
 

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One of the cheepest investments you can make for our cars (that eat up those expensive tires) is a tread depth gauge.

I vary my PS2 tire pressure as much as 4 pounds by the results from my tread depth readings.

Check the depth over the tire for even wear at least once per month and change the pressure as needed. For my (all street) driving I use about 38 front and 42 rear- cold readings, but have decreased if I start to see middle getting more ware and increased by a few pounds if the tires are worn on both edges.

If you have wear on just one edge, I would suggest a look at your alignment and suspension.
 

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lednuor said:
One of the cheepest investments you can make for our cars (that eat up those expensive tires) is a tread depth gauge.

I vary my PS2 tire pressure as much as 4 pounds by the results from my tread depth readings.

Check the depth over the tire for even wear at least once per month and change the pressure as needed. For my (all street) driving I use about 38 front and 42 rear- cold readings, but have decreased if I start to see middle getting more ware and increased by a few pounds if the tires are worn on both edges.

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I don't have PS2, but I do the same. I periodically "read" the tires. Mine seem happiest at 38/42, Dinan III suspension, stock wheels all around.
Regards,
Jerry
 

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Discussion Starter #14
Pressures now set to 36 F / 39 R. Stock 18" wheels and stock suspension. Just want to test what PS2 handling is like at that end of the continuum...

David
 

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You didn't state your goal. I assumed you meant for best performance, I answered 34-34.

For best COMPROMISE - performance, tire life, fuel economy - I run 38/40
 

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The range of replies in this thread is unbelievable! I guess I can just set my pressures in the higher range once I get my M, and never worry about them again, if a 10lb drop isnt *neccesarially* detrimental and tire wear is not a major concern.
 

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Discussion Starter #19
E55AMG2 said:
It really depends on tires, I've found that the michelins understeer less with more air in them (to a point, of course).
Do you think that might be from the sidewalls rolling when you corner hard with low-ish tire pressure?

David
 

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I dont have 18 inch PS2's, but I noticed that your poll does not include higher pressure front and lower rear. I've found that about 40 psi front, and 38 psi rear is ideal. Since the beast is understeer happy, running more front pressure and less rear pressure helps rotate the rear a bit easier. :wroom:
 
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