Ideal tire/wheel combination for comfort/noise with some handling chops?

[BoostRabbitGT]

...still working on this one.

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[keithwalton]

I'm currently debating whether to make this a "BoostRabbitGT has lots of questions about potential mods for a potential GT" thread or make separate threads for each of my questions.

While I'm still more than a year away from making any commitments to purchase/order a GT, I want to prepare as much as I can beforehand.

My first question is regarding tires and wheels. If I were to customize my GT, I'd like to make it a sleeper grand touring cruiser that can occasionally take spirited driving through twisty bits reasonably well. My questions then are as follows:

1. Do tire and wheel choice play an important role here for handling, or is that more on the suspension bits?

2. If I'm prioritizing comfort/noise over handling, should I be going for a larger diameter and/or a wider width tire? Currently I'm thinking of a square setup with 18" rims would be the way to go. 20" rims felt too harsh (but well-damped compared to a WRX) for me when test driving a GT, and I currently drive a '19 EcoBoost with OEM 19" rims (Black Accent Package), which feel better than the 20s but still ride fairly stiff (yet well-damped somehow).

3. Does anyone make a three spoke wheel nowadays? (Something like the SN95 rims, but modernized and painted white perhaps?)

No and No, for comfort / noise you want the smallest wheel size and thus tyre with the biggest sidewall you can get, and get a 'touring' tyre not a UHP one. A narrower tyre would reduce noise as well and less likely to get tramlined.
Tyres make up a lot of the compliance in the suspension and as for handling etc F1 stuck with 13" rims for as long as they could. The modern size is just not as good.

 

[BoostRabbitGT]

No and No, for comfort / noise you want the smallest wheel size and thus tyre with the biggest sidewall you can get, and get a 'touring' tyre not a UHP one. A narrower tyre would reduce noise as well and less likely to get tramlined.
Tyres make up a lot of the compliance in the suspension and as for handling etc F1 stuck with 13" rims for as long as they could. The modern size is just not as good.

(I'm new to modding in general, please be patient with me if you can!)
I understand why you'd go with a smaller rim and I agree there, but I'm not sure I understand the logic behind less rubber on the tire aside from "less product = less noise, more comfort". Does this mean then that you can't have quiet comfortable tires without sacrificing handling prowess universally across the board? Thanks for your reply regardless!

 

[keithwalton]

A narrower wheel / tyre is lighter (same for smaller rim too) and less unsprung weight is generally a good thing.
Low profile tyres are generally an atheistic thing over a performance thing and only make a difference when you push them 10/10ths

The brand / type of tyre makes far more difference on how it feels than it's size.
By type i mean All season/ Summer, UHP, SUHP, Road legal track. Etc

You will find that certain types of tyre are only available in certain sizes which will limit your choice.

Hopefully someone will do a back to back at some point with the mustang on it's 255/275 summer pirreli's (Pzero's not trofeo's) compared to the all season conti's in the same size.

Noise wise it is just less in contact with the ground makes less noise.

I would suggest looking up some tyres on the UK websites, we don't get the same tyres as you guys (nothing goes over 30k miles really) but every tyre must be sold with an EU tyre label, which has a noise rating for the tyre in db. (+3db = doubling of noise) you can explore the same tyre across different wheel diameters and widths and see the impact it makes on noise / fuel efficiency etc.
You'll also be able to see the spread in ratings for the same size across different models / brands.

Edit attached screenshots of the stock PZ4's in front and rear fitment.

Note on the front standard rating is 70db, XL (which i think the mustang uses) is 71 db, however that is an I* which means its made for BMW

At the rear size the rating is 72db for being just 20mm wider.
Although there is a mercedes tuned (MO) tyre that is cheaper, more fuel efficient and 3db quieter and the same in the rain ... has to be some compromise in there somewhere!

For other reference there is a brit on youtube who posts detailed tyre nerd stuff under the name of tyre reviews, he does a lot of american content these days and he has done a does wheel size matter review a few years back using 3 different sizes of wheel / tyre combo on the same car with the same brand / model of tyre

 

[erocker]

I went with 19x10 wheels and 285/35's all around. Don't even get any tramlining, I'm very satisfied with the choice.

 

[Gregs24]

No and No, for comfort / noise you want the smallest wheel size and thus tyre with the biggest sidewall you can get, and get a 'touring' tyre not a UHP one. A narrower tyre would reduce noise as well and less likely to get tramlined.
Tyres make up a lot of the compliance in the suspension and as for handling etc F1 stuck with 13" rims for as long as they could. The modern size is just not as good.

F1 used 13" wheels to limit brake performance as much as possible. It was part of the frequent performance limiting features in F1 to limit car speed and make them driveable by humans! The current larger wheels were introduced together with a complete change in the way the cars generate downforce so cannot be viewed in isolation. The 13" wheels are not better, they were worse!

Tyres are an undamped spring and the deeper the sidewall the more spring there is, hence the reason high performance tyres are low profile. Ideally you want all the suspension movement carried out by the suspension not the tyre, which is OK on a track, but on the road it is too rough to be feasible.

 

[keithwalton]

F1 used 13" wheels to limit brake performance as much as possible. It was part of the frequent performance limiting features in F1 to limit car speed and make them driveable by humans! The current larger wheels were introduced together with a complete change in the way the cars generate downforce so cannot be viewed in isolation. The 13" wheels are not better, they were worse!

Tyres are an undamped spring and the deeper the sidewall the more spring there is, hence the reason high performance tyres are low profile. Ideally you want all the suspension movement carried out by the suspension not the tyre, which is OK on a track, but on the road it is too rough to be feasible.

F1 tyres still have massive sidewalls compared to modern road cars at 130mm and still bigger than my old subaru's 205/60R15's.

F1 cars used to have 170mm sidewalls and run tyre pressures in the teens psi.

They were changed because Pirreli wanted them to have a more modern look, brake size has not significantly changed, they had used the space for airflow management and tyre thermal management.

I agree ideally you do want the suspension to do all of the work but it's too much of a compromise and practically impossible with modern designs.
The spring pre-load required to support the weight of the vehicle makes the spring rate on coil springs is to high. Which pushes the natural frequency higher.

Tyres provide a bit of low spring rate compliance and use the air pressure as both the spring and damper.

My old citrreon's hydropneumatic suspension had by far the best ride quality of any car i've ever owned.

On road cars the claim is low profiles give better steering response due to less flex. This can be true but the feel comes from the steering geometry far more. (Amount of Toe, Castor and Ackermann angle)

On the track you want to keep your car as stable as possible to maintain downforce and weight distribution. you just need to be able to ride the kerbs.
On the road you want to be isolated from the majority of the imperfections in the road.

 

[Gregs24]

F1 tyres still have massive sidewalls compared to modern road cars at 130mm and still bigger than my old subaru's 205/60R15's.

F1 cars used to have 170mm sidewalls and run tyre pressures in the teens psi.

Actually the sidewalls are 30 profile (ish) so much lower profile than your Subaru. Yes the sidewalls are a bit taller, but the tyres are 405/32R18, so profile wise they are very low. Your Subaru had 123mm sidewalls on tyres half the width.

They still run very low pressures (low 20's psi) and would run lower if Pirelli would let them!

 

[BoostRabbitGT]

Thanks everyone. With all this information, I'm thinking of running a square setup with a 265 or 275/40R18. I could do 265 or 275/40R19 as well, recognizing that the larger wheel sacrifices comfort for a "nicer" tire/wheel profile. Problem is neither Tire Rack's or Discount Tire's website really lets me configure a tire/wheel package that way. I guess my next question is, what would be your recommendation for a comfort-oriented R18 or R19 square setup?

Question #2 would be which brand(s) of wheels would be recommended for price and quality for someone on a budget?

 

[Radiant]

Does this mean then that you can't have quiet comfortable tires without sacrificing handling prowess

It's a "pick two" situation: comfort, handling, cost. If you option MagneRide dampers, you gain better handling and comfort. No tradeoff other than to your wallet. Same for performance tires like Michelin Pilot Sport 4S: they're quiet, comfortable, and have incredible traction.

 

[Radiant]

And my brief test drive with the Performance Pack, it seemed noisier underneath the car than without it (loose dirt and gravel were more audible than desired).

Yup, for sure. Without magnetic dampers, the performance package is so much more rigid that it affects ride comfort. The "stock" GT and the Dark Horse represent the two most comfortable setups in my opinion.

 

[snakeyes]

Question: 2024 GT Premium PP pack, Mag Ride...

will this tire and wheel setup work -

Front 20x10 offset +35, Nitto NT555G2 285/30/20

Rear 20x11 offset +50, Nitto NT 555R2 305/30/20

 

[BoostRabbitGT]

The "stock" GT and the Dark Horse represent the two most comfortable setups in my opinion.

As of today, I think I've finished test driving all the GTs I need to. Everything else I'd be looking at would be purely aesthetic. I think the main takeaways from my test drives are as follows:

1. The tires on the S650 are likely better quality than my EcoBoost's Pirelli all-season tires (the ones that came with the Black Accent Package). This goes for the 18" x 8.5 and 19" x 8.5 wheels. I honestly couldn't tell the difference with ride quality, comfort, or quietness between the two. (I will pass on the 20s as I felt they were kind of unwieldy on bumpy roads, but more so I didn't like how the rims looked.)

2. If it wasn't the tires, then I think the S650's standard suspension must have been better damped. It soaked up harsh bumps noticeably better and didn't feel as stiff as my EcoBoost, but it was still firm enough to not feel floaty at all.

3. The 10A shifts significantly smoother, both in Normal and Sport+. On a related note, throttle response is so much smoother and straightforward for me with the 5.0 compared to the 2.3. I would dare say the GT is easier to drive consistently than the EcoBoost, at least with an auto transmission. Definitely daily-driver worthy in my humble opinion.

4. Brakes seem a little more difficult to execute a chauffeur-style stop (I think that's what it's called when the car stops so smoothly it's virtually imperceptible). But that could just be something that improves over time and familiarity.

 

[BoostRabbitGT]

...265 or 275/40R18. I could do 265 or 275/40R19 as well...

Okay, I think I just realized that 265 or 275 is referring to the tire width, and 40 is referring to the tire diameter. I had them mixed up the entire time. Yikes...

On a related note, when I try to configure tire/wheel setups on Discount Tire/Tire Rack's websites, there are significantly less options available for the non-PP 19" wheels (I get more than plenty for the 18" wheels). Why is that, and should I be looking elsewhere for tire or wheel combination setups?

 

[keithwalton]

Okay, I think I just realized that 265 or 275 is referring to the tire width, and 40 is referring to the tire diameter. I had them mixed up the entire time. Yikes...

On a related note, when I try to configure tire/wheel setups on Discount Tire/Tire Rack's websites, there are significantly less options available for the non-PP 19" wheels (I get more than plenty for the 18" wheels). Why is that, and should I be looking elsewhere for tire or wheel combination setups?

The 40 is sidewall height as % of width. So a 275/40 has a deeper sidewall (thus bigger OD) than a 265/40.
Normal manufacturers staggered setup have very similar OD front and rear.
Eg my older merc had 205/55 front and 225/50 rear which gives an identical side wall of 112.5mm

As for tyre availability it depends on how widely the sizes are used on other vehicles. A common size will have a lot of options as they can easily sell them to everyone. A size only used on a couple of models of cars is niche and will end up being tailored to the demands of those vehicles.

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