Square vs. Staggered for 85D

[benf]

Since you will not be able to rotate your wheels front and back, can you explain why you would not go with the wider rear wheels and tires? Cost is the same, and they will look significantly better staggered. Is there an advantage that I don't know?

I can't rotate the wheels front and back, but I can rotate the tires. America's Tire will dismount and remount my tires to swap them front to back on the wheels as needed for the lifetime of the tires for free. If I went with different width wheels, then I'd have two sizes of tires and could no longer rotate.

That, and I figured I might get slightly better range with 245's than 275's. Not sure if it will really be a measurable difference, but it couldn't hurt. I also heard that the 85D has almost NO tendency to rotate as it is, and figured adding 275's in the rear would only make it more prone to understeer.

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I went with TSW Nurburgrings in 20x9 ET35 with 255/40-20 Conti's all around.

No issues with traction mashing the pedal to the floor on dry/clean pavement. Every first time passenger wants to experience max acceleration, and the only issue thus far was dirt/sand on the left side wheels. TC kicked in, so that passenger got a do-over.

I didn't go square so much for rotating purposes, but mainly to get extra rubber on the front drive wheels, which are doing triple duty (drive, steer, brake).

For a time I was worried that not going with 265's or 275's in the rear was a mistake. Turns out my fears were unfounded.

255's are lighter, cheaper, and have less rolling resistance. The one possible negative could be a bit of added oversteer, which I won't mind one bit.

Can you post a pic of how your rear's look in 20x9 +35? Just curious if I'm being stupid trying to get these +20's for the rear. They're special order and backordered for who knows how long, so I may just go +35's all around like you did.

 

[Battman]

I went with TSW Nurburgrings in 20x9 ET35 with 255/40-20 Conti's all around.

No issues with traction mashing the pedal to the floor on dry/clean pavement. Every first time passenger wants to experience max acceleration, and the only issue thus far was dirt/sand on the left side wheels. TC kicked in, so that passenger got a do-over.

I didn't go square so much for rotating purposes, but mainly to get extra rubber on the front drive wheels, which are doing triple duty (drive, steer, brake).

For a time I was worried that not going with 265's or 275's in the rear was a mistake. Turns out my fears were unfounded.

255's are lighter, cheaper, and have less rolling resistance. The one possible negative could be a bit of added oversteer, which I won't mind one bit.

I had researched quite a bit the implications of a staggered set up on range. Three factors come to play: weight, rolling resistance, and aerodynamics. Interestingly enough both the 245/40 and the 275/35 Continue DW's weigh the same (27lbs according to TireRack). Rolling resistance does very marginally get worse (will affect range by less than 1%). Aerodynamics are not as critical for the rear tires as the front, so very negligible. In fact it could probably be argued that 255 up front is worse than 275 on the rear. But again the differences would be well under 1%. So overall, 255/255 and 245/275 would very comparable in range, but a square 245/245 would be theoretically less than 2% better.

So far the range and efficiently for me has been very comparable to the OEM 19"s with Primacy's. If anything it might be slightly better since the wheels are 8lbs a wheel lighter.

I was initially very eager to get 255/255 or 255/285 setup because I could get Michelin Pilot Super Sports for that size. But I decided against it because it would create a slight speedometer error and some have reported slight rubbing when turning.

Regarding handling of of the vehicle, varying tire pressure can have a significant impact on understeer vs oversteer. I run 45psi front and 47.5psi rear for more neutral handling. Racing car teams do this all the time, and I have varied tire pressures for years in my previous cars (GTR and M3).

Btw, cost of the 275 over the 245 is a less than $30 difference each for two rears (for Conti DW's). On a $100k car, $60 won't break the bank. Also the advantage of rotating between front and back is relatively minor on soft compound high performance tires. Regardless you will be lucky to get 15k miles. More durable all season tires would show more of an advantage of being able to rotate front and rear. Don't buy Max Performance Summer tires if tire wear is a concern.

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I can't rotate the wheels front and back, but I can rotate the tires. America's Tire will dismount and remount my tires to swap them front to back on the wheels as needed for the lifetime of the tires for free. If I went with different width wheels, then I'd have two sizes of tires and could no longer rotate.

I would not recommend you mount and dismount the same set of tires repeatedly throughout their life. First, it hard on the tires. Second, it's a pain in the ass compared to being able to simply rotate wheels in your own garage at home. Thirdly and most importantly, you risk scratching your beautiful wheels that many more times if someone inexperienced is doing that for you (highly likely if they are doing it for free). You are better off going 35mm all around.

 

[benf]

I would not recommend you mount and dismount the same set of tires repeatedly throughout their life. First, it hard on the tires. Second, it's a pain in the ass compared to being able to simply rotate wheels in your own garage at home. Thirdly and most importantly, you risk scratching your beautiful wheels that many more times if someone inexperienced is doing that for you (highly likely if they are doing it for free). You are better off going 35mm all around.

I know it's hard to believe, but they are actually really good. I have a long relationship with this particular America's Tire and they have never scratched one of my wheels. That said, since I bought my wheels from them, if they ever do scratch it, it's on them. They'll replace the wheel for free. It's actually more convenient for me to drop the car off, grab lunch, and pick it up 45 mins later than to spend 20-30 minutes at home jacking up my car and swapping wheels around.

As for repeatedly dismounting tires, I'd probably only ever need to do it once, maybe twice. How long do the DW's last? I wasn't expecting to get more than 20-25k out of them.

 

[Terra117]

Can you post a pic of how your rear's look in 20x9 +35? Just curious if I'm being stupid trying to get these +20's for the rear. They're special order and backordered for who knows how long, so I may just go +35's all around like you did.

I haven't posted pictures to this forum before, so I don't know if these are sized appropriately. Don't know if these help. The overcast was heavy.

 

[Terra117]

Interestingly enough both the 245/40 and the 275/35 Continue DW's weigh the same (27lbs according to TireRack).

That's a bit unexpected. In terms of weight, you also have to consider the difference between a 20x9 and 20x9.5 or 20x10 wheel.

Rolling resistance does very marginally get worse (will affect range by less than 1%). Aerodynamics are not as critical for the rear tires as the front, so very negligible. In fact it could probably be argued that 255 up front is worse than 275 on the rear. But again the differences would be well under 1%. So overall, 255/255 and 245/275 would very comparable in range, but a square 245/245 would be theoretically less than 2% better.

On a day-to-day basis, the effects will be minimal. But when I drive between homes in Minnesota and Arizona (1850 miles), through mountain ranges, with sometime heavy winds, I'll take every little advantage I can get. At least until Supercharger stations are ~75 miles apart. Range anxiety is a thing.

I was initially very eager to get 255/255 or 255/285 setup because I could get Michelin Pilot Super Sports for that size. But I decided against it because it would create a slight speedometer error and some have reported slight rubbing when turning .

In the front, the circumference difference is -.7%. 55mph indicated would actually be 54.6mph. The rubbing is mild, only happens when reversing, and is easily fixed with a heat gun.

Btw, cost of the 275 over the 245 is a less than $30 difference each for two rears (for Conti DW's). On a $100k car, $60 won't break the bank. Also the advantage of rotating between front and back is relatively minor on soft compound high performance tires. Regardless you will be lucky to get 15k miles.

I didn't mean to imply the cost of tire and wheel sizes was the determining factor when I mentioned costs. $60 every 15k miles is negligible on a $135k car with an additional $10k in mods (including a full body Xpel Ultimate wrap). To be fair, when I ordered the car last Feb, there was a lot of talk about alignment and wear problems, and it was more of a problem for the wider rears. I guess I was playing it safe.

 

[Battman]

That's a bit unexpected. In terms of weight, you also have to consider the difference between a 20x9 and 20x9.5 or 20x10 wheel.



On a day-to-day basis, the effects will be minimal. But when I drive between homes in Minnesota and Arizona (1850 miles), through mountain ranges, with sometime heavy winds, I'll take every little advantage I can get. At least until Supercharger stations are ~75 miles apart. Range anxiety is a thing.



In the front, the circumference difference is -.7%. 55mph indicated would actually be 54.6mph. The rubbing is mild, only happens when reversing, and is easily fixed with a heat gun.



I didn't mean to imply the cost of tire and wheel sizes was the determining factor when I mentioned costs. $60 every 15k miles is negligible on a $135k car with an additional $10k in mods (including a full body Xpel Ultimate wrap). To be fair, when I ordered the car last Feb, there was a lot of talk about alignment and wear problems, and it was more of a problem for the wider rears. I guess I was playing it safe.

More unexpected, the 20x10" wheel is lighter than the 20x9" wheel!!! Check out the TSW website: Bathurst Alloy Wheels by TSW

The 20x10" is 0.25 lbs per wheel lighter. Perhaps range may be better with a staggered set up after all.

Sweet looking wheels btw. Since the Nurburgrings don't have the Cancave look of the bathursts, less of a cosmetic advantage of going staggered. Whereas the 20x10" bathursts look way better than the 20x9" versions because of the deeper concave look.

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How long do the DW's last? I wasn't expecting to get more than 20-25k out of them.

Obviously depends on how hard you drive them, alignment, if the car is lowered, etc. But generally speaking i think you will be extremely lucky to get 20k miles on a near 5000lb car with the Conti DW's. And that is if you drive like a grandma.

 

[Terra117]

More unexpected, the 20x10" wheel is lighter than the 20x9" wheel!!! Check out the TSW website: Bathurst Alloy Wheels by TSW

The 20x10" is 0.25 lbs per wheel lighter. Perhaps range may be better with a staggered set up after all.

Sweet looking wheels btw.

Wow. I never would have called that. Good thing I was schooled on a forum. I would have put money on the opposite. I guess I owe you one.

Thanks for the compliment on the wheels. Did you notice my in-process chrome delete matches the finish of the wheels exactly? Avery Supreme Matte Charcoal Metallic. I ordered something like 10 or 12 samples from 4 vinyl makers...anything I thought might be close. I wasn't through half a beer when I found the one that matched.

 

[Battman]

Wow. I never would have called that. Good thing I was schooled on a forum. I would have put money on the opposite. I guess I owe you one.

Thanks for the compliment on the wheels. Did you notice my in-process chrome delete matches the finish of the wheels exactly? Avery Supreme Matte Charcoal Metallic. I ordered something like 10 or 12 samples from 4 vinyl makers...anything I thought might be close. I wasn't through half a beer when I found the one that matched.

I had noticed the chrome delete, but some how missed how it matches your wheels perfectly. Perhaps if I wasn't distracted from your beautiful hub caps. The chrome delete around the side view mirrors must have been particularly difficult. Well done.

Where did you get the hub caps from?

Also, your assumption about the 10" wheels being heavier would be correct the vast majority of the time, just that the TSW Bathurst's are the exception. For instance your 9" Nuburgrings are lighter than the 10" version. I was as surprised as you were the first time I saw the numbers for the Bathurst's.

 

[Terra117]

Where did you get the hub caps from?

Thanks for the compliment on the caps. The wheels came with standard chrome caps, which seemed really odd on a dark wheel. Not what I expected or wanted, so I took matters into my own hands.

I laid up 3 layers of 3k twill between two steel plates, used a hole saw to get them just oversize, and then used double-sided tape to affix them to a hand drill bit and sanded them down to finished size. To protect them from moisture and UV fading, I used a UV blocking clearcoat on all sides (epoxy will yellow over time).

The supplied TSW center cap left a ring of chrome around the works, so I found a paint that just about matched the brake caliper. I was on the fence about this. I almost bailed on the red and went matte black instead.

About the wheels, I wonder if the weight difference between 9" and 10" wheels could be attributed to a difference in load rating? Load rating was something I looked at when selecting wheels, since the S is so heavy.

 

[benf]

I haven't posted pictures to this forum before, so I don't know if these are sized appropriately. Don't know if these help. The overcast was heavy.

Thank you very much for the pics. I just canceled my backorder for the +20's and just went +35 all the way around. While I'm sure the +20's would have looked cool, the +35's look good and it's just easier to have a "real" square setup.

 

[Terra117]

benf, make sure you get lug nuts with your wheels. My came without, and the OEM were too wide to fit in the TSW recesses. I had to order nuts. On the plus side, they're black chrome.

 

[benf]

benf, make sure you get lug nuts with your wheels. My came without, and the OEM were too wide to fit in the TSW recesses. I had to order nuts. On the plus side, they're black chrome.

I ordered a set of black lugnuts with the wheels, but thanks for the heads up. Will save someone else a headache if they see this thread .