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Experience with a 275-45-20 on Staggered sport Techno's VS. 275-40-20's?
I am thinking about the 275-45-20 instead of the 40 all around because the load rating go's from 106y on the 40 to 110y on the 45 in the case of the Atturo az850's. I don't want to do 315's on the rear 10" wide rim. I figure a bit of extra sidewall won't hurt. It's an extra 1.2 inches in overall diameter but the load rating I assume would mean a stiffer sidewall?
I run 275/45r20 on sport technos and another set of factory 20's and will not run any other combination of wheel/tire size on my cayenne. The extra half inch of sidewall makes it ride much, much smoother without giving up too much sharpness in the handling. It also fills out the wheel well and looks much better. I think they should have come from the factory like this.
I have not tried the Atturos yet, but they will certainly by next set at your recommendation.
As you say 315s are too wide for a 10" wheel. That's what I run in my 12" wheels. As another point of info, on the rear of the 997 GTS, Porsche runs a 305 on a 12" wheel, so 305-325 is the right width range for a 12" wheel. On a 10" wheel the tire needs to be narrower, like what you're looking at.
Load rating and sidewall stiffness are usually correlated, as well as the tire construction and its ability to dissipate the heat associated with carry g heavier loads. Sometimes the additional load rating also takes place at a different (higher) pressure, that may not be a pressure you're anywhere near.
If you're looking to stiffen up the ride, a higher load rating tire will probably do that. If you're looking to soften the ride and why you're going to a narrower tread width so you can use a taller sidewall, if this taller sidewall tire also has a higher load rating, those things will likely counteract each other.
On my pick-up Atturo doesn't make the AZ850 in the size I NEED (305/50-20) but they do make the AZ800 so I'm going to try them. Is there a good match in that model for the sizes you need?
As you say 315s are too wide for a 10" wheel. That's what I run in my 12" wheels. As another point of info, on the rear of the 997 GTS, Porsche runs a 305 on a 12" wheel, so 305-325 is the right width range for a 12" wheel. On a 10" wheel the tire needs to be narrower, like what you're looking at.
Load rating and sidewall stiffness are usually correlated, as well as the tire construction and its ability to dissipate the heat associated with carry g heavier loads. Sometimes the additional load rating also takes place at a different (higher) pressure, that may not be a pressure you're anywhere near.
If you're looking to stiffen up the ride, a higher load rating tire will probably do that. If you're looking to soften the ride and why you're going to a narrower tread width so you can use a taller sidewall, if this taller sidewall tire also has a higher load rating, those things will likely counteract each other.
On my pick-up Atturo doesn't make the AZ850 in the size I NEED (305/50-20) but they do make the AZ800 so I'm going to try them. Is there a good match in that model for the sizes you need?
The problem is this goofy staggered setup. I just don't get what Porsche was thinking. Ideally I would like to run a 305 on the rear 10" rim and probably a 265 on the front 9" but getting goofy with sizing gets super expensive.
What I like about the Atturo's is that they are a dedicated HP SUV tire. Atturo put some engineering and thought into the tire. I think I see a et of Finspeed wheels in my future. Their mfg. facility/headquarters is right in N. Austin so that only adds to the quality and value of the product. I can go in for a custom fitment. I'd like to go as wide as possible on the rear maybe 335 and likely a 295 on the front.
For now I have decide on the 275-45-20 AZ850. $426.24 for 4 of them from Walmart.com delivered to my house free. I can take them to the local Walmart tire store and have them installed for an additional $60.
How can you beat that? The 20's should actually perform a bit better on acceleration and they are significantly lighter than the OEM GTS 21's wheel/tire combo. Love the GTS 21's but they are stupid expensive used and I want to do something different this time around that you won't see everywhere. So I will run these sport Techno 20's for a while.
Fwiw, I ran the 10" concave set all around (I bought a second set of sport technos just for this) with, IIRC, 305/35 R20s on my blue CTTS. Go check my thread, it worked. I also didn't want to go staggered on tires.
I have had 3 955 CTTs now and they have all had different tire sizes. These observations are all with each car durametrically lowered in "low" height and "normal" shock setting.
1 had 20" technos - 9" wide with 275 fronts and 305 or 315 rears. I actually assumed this car had 10" rear wheels due to tire size but was surprised when I removed the wheels that they were all 9". The wider rears looked cool and had no issues. I think sidewall height was 45 front 40 rear maybe but not sure, its been over 5 years.
1 had 20" technos with 275/45/20s. These were a lot better ride quality, they were DWSs. I downgraded to 18's when I sold it and with 18's it was super comfortable but the look is not as good as 20s.
Current CTTS has 275/40/20 DWs and 275/40/20 snow tire set. You can notice the increased handling from the summer tires but the 40 sidewall is a rougher ride. I actually drove the summer tires until march in Iowa, but I do not recommend it.
I would definitely recommend the 45 sidewall. The look is better because it fills out the wheel well, too. It's a win-win.
Fwiw, I ran the 10" concave set all around (I bought a second set of sport technos just for this) with, IIRC, 305/35 R20s on my blue CTTS. Go check my thread, it worked. I also didn't want to go staggered on tires.
I assume you mean that you picked up a second set and took the 10" wide concaves from the second set and put them on the front, leaving you with 4 of the 9" wide wheels? I actually thought about this and 4 305/35/20's would have made me very happy! I did not pursue this because Atturo doesn't have a 305 in the az850 and the 295/45 they offer is way too much sidewall. Alas I have contacted Atturo asking them to explore a few more sizes of tire such as 325/30/21 like on the x5/6 m's and the 305 section. I really like the Atturos so for now I want to try and stick with them. For what they cost I can eat em up all day. The load rating is killer, and they are actually approved for up to 186mph. This would make me feel more comfortable to try reaching for that 200+ mph without having to spend $2400 on a set of tires.
Originally Posted by 1999Aero911
I have had 3 955 CTTs now and they have all had different tire sizes. These observations are all with each car durametrically lowered in "low" height and "normal" shock setting.
1 had 20" technos - 9" wide with 275 fronts and 305 or 315 rears. I actually assumed this car had 10" rear wheels due to tire size but was surprised when I removed the wheels that they were all 9". The wider rears looked cool and had no issues. I think sidewall height was 45 front 40 rear maybe but not sure, its been over 5 years.
1 had 20" technos with 275/45/20s. These were a lot better ride quality, they were DWSs. I downgraded to 18's when I sold it and with 18's it was super comfortable but the look is not as good as 20s.
Current CTTS has 275/40/20 DWs and 275/40/20 snow tire set. You can notice the increased handling from the summer tires but the 40 sidewall is a rougher ride. I actually drove the summer tires until march in Iowa, but I do not recommend it.
I would definitely recommend the 45 sidewall. The look is better because it fills out the wheel well, too. It's a win-win.
315 sounds uber scary on a 9" wide wheel. I would notice that right away. Try a "Moose" test with that! I dare you! I won't do it on the 10" wide wheel and I am skeptical that the 275/45's wont be all squiggly. I tend to drive rather aggressively at times. Apparently you must drive like a granny, have ***** of steel that you carry in a custom made *******, or just don't GAF because your skilled like
Mario Andretti.
Yeah, I bought another set of staggered ones and use the 9" for winter / AT setup and 10" for summer rubber.
I think I ran either 305 or even 315 on the 10". I switched to 295/40 for the last set. Now Injust have bare wheels and the blue pig sits on 275/45 ATs on 9" sport technos.
Another vote for 275/45 here - I changed from 275/40 and instantly noticed the extra comfort, pretty close to the stock 18s but with sharper responses.
I have a set of Sport Techno's with 275/40/20 on non staggered 20x9 wheels. I have a set of 275/45/20 tires to put on once the Conti's are done.
I have a set of 19" wheels with 265/50/19 tires for winter and can tell the difference. Very comfortable!
I bought another set of staggered 19x9's & 10's, but have decided to sell them when I get a chance and run the 20's in the summer. I really do not want to get into the different tire sizes.
It is fun to try out the different wheel sizes, ride comfort, and the handling differences associated with set.
This thread was more geared towards the performance tire aspect of Cayenne land. Obviously mine is dedicated to going real fast so in the spirit of that topic I wanted to get opinions on the 40 vs. 45 series in a 275/20. I wont ever be interested in going less than a 20 unless it was 18's and slicks. Ride quality for me is secondary at this point. I've only ever had the 295-35-21's and I was very happy with those. I think 22's are too big in many ways and with more and more choices coming in the 21's it's a nice space. I tend to like more connected vehicles and at the expense of ride quality is fine.
I will post up some pics and an opinion of how this combo compares to the 295-35-21's.
05-17-2019, 08:13 PM
Experience with a 275-45-20 on Staggered sport Techno's VS. 275-40-20's?
