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21" Rims on 265/35 R21 Tires

Discussion in 'Model S' started by m2140, Jun 18, 2016.

  1. m2140

    m2140 Member

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    I recently had to replace the tires on my Model S 85D. But i did not want to go back to the stock tire size. As many of you know. the stock 245/35 R21 tires look skinny on the 21 in wheels. The tires also don't quite fit in the wheel wells an make the car look a little off. The Continental sport tires have a built in rim protector but they don't quite fit right on the 21's and offer no protection. Also, the stock tires cannot be repaired. I you get a nail your only option is replacement because of the Foam inside the tire.

    Well this past week I got a leak in the tire and turns out I had a nail. None of my local tire shops would repair the wheel, or even attempt to repair it. I had 24,400 miles on the tires so they were about done anyways so it was time for a whole new set. I tried to look in the forums for advise for getting a larger time and there was not much. Everyone cautioned that a 265 would rub but no one had tried it. The discussion always de-evolved to; you should have gotten the 19s or get aftermarket 20's.

    So i took a risk and got a set of 265/35 R21 Continental Sport P5 tires. These are the black wall tires and they are not the foam core CSI or silent tires. I wanted a tire that could be repaired. At $375 a tire I don't want to have to pay for a new tire every time I get a nail or something.

    I'm so glad I did. The tired look AMAZING. The tires are wider but also slightly taller than the Stock wheels. Here are my first impressions:
    - Much better look, the tire fills in the wheel well and the wheel don't look skinny anymore
    - RIM Protection. The rim no longer sticks out father than the wheel
    - Same road noise. I have not noticed an increase in road noise. I fact I think it sounds a little quieter
    - The ride seems to be smoother.
    - No rubbing. I have turned lock to lock with no rubbing.

    I'm going to be taking a couple of longer trips this weekend to fully try then out and will update.
     

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  2. sorka

    sorka Active Member

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    Turned all the way to the left or right, I have about 2mm of clearance between the outside front edge of the tire and the wheel well liner. ANY thing larger would blow that clearance.

    Are you saying that if you turn all the way left or right that this larger diameter tire isn't touching the wheel well liner?
     
  3. m2140

    m2140 Member

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    I had a chance to do more driving today and in forward driving there is no touching. reversing out of a driveway on the other hand where the suspensions moves a little there is some rubbing when the wheel is turned all the way.

    But The handling is improved, the rise is smoother, and the wheels and the car overall looks much better.
     

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  4. sorka

    sorka Active Member

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    Cool. Let us know how wh / mile change if they do. Presumably they have to since you're going wider and heavier tire.

    Also, since the diameter increased, there are fewer revolutions per mile so the car will think it's going slightly less distance so if efficiency stayed exactly the same it would appear you get higher wh / mile than you really are. Stack that with an actual slight worse efficiency and you'll see worse than actually get even though part of it really is higher wh / mile.
     
  5. Tdriver

    Tdriver Member

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    All new tires feel smoother because you have more tread depth that acts to insulate road noise and roughness.
     
  6. Norfolk Enchants

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    #6 Norfolk Enchants, Jun 28, 2016
    Last edited: Jun 28, 2016
    Looks like a much better fit in the pictures. I am thinking about making the same change to 265/35/21 after my favorite (gentle and trouble free for years with many of my other cars) carwash just wrecked one of my rims. I have a couple of questions:

    1) This is almost a 2% increase in tire diameter. What will be the effect of this increased load on the motor?

    2) Is the 265 tire within the recommended mounting width for a 8.5" wide wheel? When I was looking on line the max recommended tire width for a 8.5" wide wheel seemed to be 245.
     

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  7. Jeff4155

    Jeff4155 Member

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    Technically the tread width is wider not the diameter of the wheel sins the tires stays 35 profiles on the 21" rim, this will probably affect your wh/mile negatively by a small margin because you have a larger tread pattern on the road, but could also be saver when going into a corner at speed.
     
  8. Vrrooom

    Vrrooom Member

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    This is wrong. The sidewall is larger. 35 indicates 35% of 245 is the sidewall size. Now he has a 265, so the sidewall is now 35% of 265, which means a bigger sidewall and also a larger diameter.

    I think this is a great option to protect the rims. Also, with the tires having more sidewall, it offers better protection not only from curbs but also from potential blow outs. The clearance on the front tire to inner fender does look really tight and I'm surprised there isn't more rubbing. However if it's very slight and not noticeable or audible and in reverse under a turn only, it could be the worthy sacrifice to offer better protection against potholes and blow outs.
     
  9. Speedeamon

    Speedeamon Member

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    I would like to know how much rubbing there is in hard cornering. This is when the tire will shred some rubber from the abrasion and create a dangerous situation
     
  10. m2140

    m2140 Member

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    Update:

    Energy consumption:
    - I have noticed a slight increase in usage. i used to average around 340 w/hr and now i'm averaging between 350-370 w/hrs. So it's a very slight increase. Last week I got a Loaner while my S was in for the yearly maintenance and was surprised to find that the P90D loaner I was using had 265/35/21 tires on the rears. Maybe some of the P90D guys reading this thread and can post about their regular consumptions without aggressive driving to see if it's about the same.

    Performance:
    - Handling and feel of the car is very much improved. I drove Ortega this weekend and got really lucky with open road for a while. The ride felt far more stable. With the 245's if i hit a conner too fast you could feel some serious give on the tires like it was about to pop a bead. But with the 265's the ride is more stable with less give and no tire squealing.

    Rubbing:
    - There is a lot more rubbing on the front tires at the front & back of the wheel well. There is no rubbing when the tires are turned all the way. Rubbing only occurs at about 2/3 rotation of the front tires on the front plastic wheels wells and sometimes on the felt. When going in reverse this rubbing creates a noise as the tire rubs on the vent slot for the radiators.

    To fix it this weekend I tried a couple of things:
    - Rubbing on the Felt (rear of the front wheel well) Cannot be reshaped. There is a bracket that hold some connections and the windshield washer fluid directly where the rubbing is at. The rubbing is minimal so I'm Ok with it.

    - Rubbing on the front wheel wells: the rubbing is on vents for the radiators. They make a lot of noise in reverse when the wheel is at about 2/3 only. I took off both the front wheel and I was able to re-shape the plastic covers using my heat gun. Using a tape measure all I needed was about 1/2 in of give and I was able to get that on both wheel wells. It's still very tight, but with the suspension in standard there is no rubbing. With the suspension in very high there is still rubbing. I'm going to leave this setup to see how it work out for a couple of weeks.

    I don't want to cut out the section that rub just yet. I will try this for a while and see. If the rubbings comes back I may remove the liner and try to more aggressively reshape the plastic. In hine sight, It may have been a better option to go with a 265 / 30 tire so that the size was about the same. As someone previously posted the 2nd number is a percentage of the first number. a 30 tire would be smaller and probably would have no rubbing. I will try that on the next set of tires. IMG_1733.jpg


    IMG_1734.jpg IMG_1732.jpg
     
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  11. HankLloydRight

    HankLloydRight Fluxing

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  12. bradjc

    bradjc Member

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    Thanks m2140 for posting this, I've got some 20x9 T-Sportline wheels with Michelin Pilot Super Sport 255/40/20 on the way and have been told from others with experience there'll be a rub, especially in reverse. That's good to hear that it can be minimise somewhat with a bit of modification. Hoping the heat gun method works for me. How did you go about it? Heat the area and apply a bit of pressure to the area? I had thought about sanding back a bit of plastic from the hot spot, but not sure about the felt side. I'll know more about how much of a problem is when fitted but good to hear you've had some success. I was wondering how much of a problem it would be! Make sure you post any updates if you decide to do any more work on it! Cheers.
     
  13. Norfolk Enchants

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    Went ahead and fitted my P85D 265/35/21s Contisport 5P tires front and rear thanks to the recommendation of m2140. So glad I did. Looks better, rims actually now have a modicum of protection so that I can carwash the car, and yesterday with the car fully loaded with the family, no rubbing as far as I could tell - and I was testing for this with an enthusiastic drive!

    Honestly, this car is great, but it was not practicable for me to keep with the factory wheel/tire combo and I was actually considering offloading it. Living in MI the use of a winter carwash is a must, but I couldn't stand the wheel cannibalization when doing so. Looks like now I will be able to keep it. :)
     
  14. Jeff4155

    Jeff4155 Member

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    I must admit I didn't know this, always thought one 35 profile is the same as another, you learn something every day, so the circumference of the wheel will be larger, but will it really make that big of a difference?
     
  15. bradhs

    bradhs Member

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    So you were able to fit 265 35 R 21's on the front rims?? I've put 275's in the rears on my staggered set up, that was the max tire according to specs. 265's on the front seems outside of specs, but likely would still fit.
     
  16. Norfolk Enchants

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    #16 Norfolk Enchants, Jul 7, 2016
    Last edited: Jul 7, 2016
    Yeah, seem to fit just fine. Here is a pic of the 265/35/21 on my front rim. Have no idea why anyone would think this tire is too wide for the 21x8.5 rim (even though Conti doesn't flag it as a recommended fit). Looking at this pic, it is the absolute minimum to garner any sort of wheel protection whatsoever. If you gunsight the standard 245 on the 21" rim, you can see that the first point of contact with anything outboard is the rim itself - unbelievable!

    265-35-21 on MS 8-5 J.jpg
     
  17. bradhs

    bradhs Member

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    Do you have air or coil suspension? 8 have air. I wonder if it will rub on the low setting.
     
  18. Norfolk Enchants

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    I have air. Car is usually on Low setting, and I haven't had any issues. That's not to say others wont - every MS will be built a bit differently - but I would think any clearance issues would be contained to the front only and minimal.
     
  19. Vrrooom

    Vrrooom Member

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    It depends on the vehicle... The S has some tight clearances on the front wheel, so much so that people rub with factory sizing as well. So even a slight increase can have an impact. Google tire size calculator and play around with a few different sizes, it explains it visually as well.
     
  20. 3s-a-charm

    3s-a-charm Active Member

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