295/45ZR18 too much sidewall?

[SSSoon]

I'm thinking of getting 18x10s all around, with Nitto NT05 295/45ZR18s.

Benefits: Really light rims (21 lbs per rim), maintains stock ride height (I am already lowered and scraping on speed bumps), really sticky tire for track and can run on street too.

Possible drawbacks: Very tall sidewall, some grinding of knuckle required (no biggie).

Nine Ball cautions that this high sidewall could negatively affect hard cornering on a road course.

Anyone actually running this combo who could comment?

Tony suggests shorter tires, but that would drop me another inch and require tuning to calibrate correct speed, etc. On the other hand, a shorter tire is more response in turns maybe



Thanks

[rtcat600man]

I am looking at doing something similar, but going with the 285/40/18's I know I will drop approx. another inch, and need to be re-calibrated. That is what tunes are for.

Subscribed to hear other responses too.

[SSSoon]

I'm just playing around with different combos to get total weight of tire + rim here, in case anyone finds this useful.

OPTION 1 : LIGHTEST KEEPING OEM RIDE HEIGHT
18x10 F14 wheels = between 21 lbs (courtesy of Nine Ball)
Nitto NT05 295/45ZR18 = 33.22 lbs (hard to say, Nitto does not list but some resellers list weight. These from tireswheelsdirect.com)
TOTAL = 54 lbs. Light, but huge sidewalls. Tire is 28.46 high, so that means 5.23 inch sidewalls

OPTION 2A : FATTEST REARS OEM RIDE HEIGHT
20x10.5 F14 wheels = 28 lbs
Nitto NT05 315/35/20 = 35.86 lbs
TOTAL = 64 lbs
But, this is a much fatter tire. OEM is 64 rear. Tire is 28.6 high, so 4.3 inch sidewalls.

OPTION 2B : MATCHING 20 INCH FRONTS OEM RIDE HEIGHT
20x9.5 F14 wheels = 26.5 lbs
Nitto NT05 275/40/20 = 33.51 lbs
TOTAL = 60 lbs. OEM is 60.7 front. Also 4.3 inch sidewalls.

OPTION 3 : LIGHTEST AND SCREW OEM RIDE HEIGHT
18x10 F14s = 21 lbs
Nitto NT05 295/35/18 = 29.7 lbs
TOTAL = 51 lbs. But this is only a 26.18 inch high tire, so car gets lowered, gotta tune for phantom mileage, etc. But, 4.14 inch sidewalls.


I still gotta say that Option 1 looks great on paper but I wonder what the extra inch in sidewall does.

Option 2 gets more meat on the back but at quite a weight cost (+10lbs each back wheel, +6 lbs each front vs Option 1).

Going with Option 3 and a tune would be cool but I would be swapping back to my winter tires at times (gotta drive in snow sometimes) and so would be swapping tunes, etc. too.

The reason I am obsessing on weight is that apparently rotating mass has a big impact - some say 1 lb of reduction in unsprung weight is the equivalent of 10 lbs reduction of sprung weight. So, 32 lbs diff = like having a car that is 320 lbs lighter. (not saying for sure this is true, but what I have heard)

Would love to hear from people who are doing any of the above (esp Option 1) and who have personal experience with that sidewall height on road course conditions.

[JusticePete]

Everyone has opinions and this is mine. I am not a fan of the Nitto range with the exception of the NT05. The OEM Pirellis are a good quality tire woith good grip, but that are too tall. When we looked for a replacement we settled on the Bridgestone RE-11 305/30/19/XL for several reasons. It is by far, again in our opinion, the best combination street track tire on the market. The only size they had available to suit the Camaro was and is the 305/30/19. Michelin Pilot Sport IIs are a great tire and available in sizes to suite the Camaro. Our choice in this range would be the 305/35/20 on a 20x10.5 rim. We ran this on the LPE L/28. They performed very well, but not as well as the RE-11 in the smaller size. The new Super Sport is a very good tire available in a 295/35/20/XL, 29 pounds and at 27" is only a bit over an inch smaller than the OE Pirellis. They should be mounted on 10.5" rim width. If I were to go with a 20" wheel again, this would be my tire choice.

The XL designation is important is you run aftermarket wheels They protect your wheels. Getting your tires mounted on the correct rim width is mission critical. Based on the number of Camaros we have set up, we and the owners have settled into thinking the 30 profile is best.

The bigger the rear tires, the more push your 5th Gen will have. It isn't as well balanced or as light as a Vette where the staggered setup is highly desirable. We already have more than enough push in the 5th Gen.

I vote for Option #4 Michelin Super Sport 295/30/20/XL on 20x10.5 wheels.

Again, these are just my opinions.

[SSSoon]

Originally Posted by JusticePete

The new Super Sport is a very good tire available in a 295/35/20/XL, 29 pounds and at 27" is only a bit over an inch smaller than the OE Pirellis. They should be mounted on 10.5" rim width. If I were to go with a 20" wheel again, this would be my tire choice.

The XL designation is important is you run aftermarket wheels They protect your wheels. Getting your tires mounted on the correct rim width is mission critical. Based on the number of Camaros we have set up, we and the owners have settled into thinking the 30 profile is best.

I vote for Option #4 Michelin Super Sport 295/30/20/XL on 20x10.5 wheels.

Again, these are just my opinions.

Hey Pete, thanks for your thoughts. Very helpful.

Obviously the specific brand / design / rubber compound used is important, but if we took that out of the equation for a moment (assume we are talking about the same tire in all configurations), would you say that:

1: tire width and aspect ratio is MORE important than wheel weight when it comes to road course performance?

2: the upside of a drop in wheel weight from smaller diameter rims is LESS important than the downside of a taller sidewall, based on what you have seen (again, assuming a road course scenario not a drag strip scenario)?

It really helps to hear experience talkin'... thanks man.

Pete

PS I just checked the weights:
Forgestar F14s 20x10.5 = 28 lbs (thanks to Nine Ball)
Michelin Super Sport 295/30/20/XL = 29 lbs
TOTAL = 57 lbs per wheel
SAVINGS vs OEM = 4 lbs on each front wheel, 7 lbs on each rear = 22 lbs savings total. In the best 18 inch scenario above I had a total of 32 lbs savings I think. Almost doesn't seem worth it to go for the 18 now that I calculate it out.

[SUX2BU]

When I first got my 18s I originally went with 28" tires and it handled like crap compared to the stock 20" tires. I was at the tire shop getting them taken off with in 30 min. I went with stock sized sidewall tires and it was a world of a difference! The handling back and then some, it didn't feel like an SUV anymore.


If you aren't going with a shorter tire with the 18s, then I wouldn't do it.

[JusticePete]

Originally Posted by SSSoon

Hey Pete, thanks for your thoughts. Very helpful.

Obviously the specific brand / design / rubber compound used is important, but if we took that out of the equation for a moment (assume we are talking about the same tire in all configurations), would you say that:

1: tire width and aspect ratio is MORE important than wheel weight when it comes to road course performance? and Contact Patch. There has to be enough suspension and enough sidewall flex to keep the tire on the track surface. I would trade a couple of pounds for a bigger contact patch and increased control. Now is we are talking slicks the 18s...

2: the upside of a drop in wheel weight from smaller diameter rims is LESS important than the downside of a taller sidewall, based on what you have seen (again, assuming a road course scenario not a drag strip scenario)?

Yes sir.

It really helps to hear experience talkin'... thanks man.

Pete

PS I just checked the weights:
Forgestar F14s 20x10.5 = 28 lbs (thanks to Nine Ball)
Michelin Super Sport 295/30/20/XL = 29 lbs
TOTAL = 57 lbs per wheel
SAVINGS vs OEM = 4 lbs on each front wheel, 7 lbs on each rear = 22 lbs savings total. In the best 18 inch scenario above I had a total of 32 lbs savings I think. Almost doesn't seem worth it to go for the 18 now that I calculate it out.

[SSSoon]

Originally Posted by JusticePete

The new Super Sport is a very good tire available in a 295/35/20/XL, 29 pounds and at 27" is only a bit over an inch smaller than the OE Pirellis. They should be mounted on 10.5" rim width.

Did some digging, and am trying to get my head around the pros/cons of different rim sizes.

Michelin lists rim size as 10-11 inches for the above tire.

Forgestar has lightweight CF10, 20x10, that they list at 24.6 lbs.

Curious as to why you would recommend a 10.5" rim width over a 10" (or even an 11") and what the difference would be (driveability, sidewall flex, rim protection ...?)

Really appreciate your thoughts!

[cajun1le]

Thanks SSSoon for starting this informative thread.


On a side note. I just wish tire manufacturers (namely Bridgestone) release tire sizes that would better complement the maro. The available selection of compatible tire sizes and manufacturers for the camaro is pathetic...

For instance, I'm still trying to figure out a good road course tire for the camaro and the events I need the tires for has size restrictions. If I choose to go with what Bridgestone currently has available in the RE-11's, I am limited with the 285/35-19's. That works out to being almost 1 1/2" shorter that the factory tire sizes. A 285/40-19 or 285/45-19 would be perfect but they don't exist...

[SGOS252382]

Originally Posted by SSSoon

Hey Pete, thanks for your thoughts. Very helpful.

Obviously the specific brand / design / rubber compound used is important, but if we took that out of the equation for a moment (assume we are talking about the same tire in all configurations), would you say that:

1: tire width and aspect ratio is MORE important than wheel weight when it comes to road course performance?

2: the upside of a drop in wheel weight from smaller diameter rims is LESS important than the downside of a taller sidewall, based on what you have seen (again, assuming a road course scenario not a drag strip scenario)?

It really helps to hear experience talkin'... thanks man.

Pete

PS I just checked the weights:
Forgestar F14s 20x10.5 = 28 lbs (thanks to Nine Ball)
Michelin Super Sport 295/30/20/XL = 29 lbs
TOTAL = 57 lbs per wheel
SAVINGS vs OEM = 4 lbs on each front wheel, 7 lbs on each rear = 22 lbs savings total. In the best 18 inch scenario above I had a total of 32 lbs savings I think. Almost doesn't seem worth it to go for the 18 now that I calculate it out.

Yes, but the stock tires are only 245s front and 275s rear. In the example above, you're using 295 series tires (much wider front and back). So your losing rotational mass (not just static weight) and running a wider tire front and back (larger contact patch).

I just know the drag racing guys save a ton of weight going to 18" wheels. Here's Padre's example using TSW Nurburgrings (which I run in 20").
Not the best road course setup (too much sidewall in his tire choices), but it puts wider tires up front and back. For drag, an even skinner front tire would be better.

TSW Nurburgring 18x8 (35mm offset), 18x9.5 (40mm offset), matte gunmetal
Nitto 555, 265/50-18 and Nitto 555R, 305/45-18 - these maintain the stock height.

Fronts weigh 50.5 lbs each vs. 62.3 lbs stock.
Rears weigh 53.5 lbs each vs. 68 lbs stock.

104 lbs vs 130.3 lbs.
So that's a 26 lb reduction in rotational mass and the ability to run a 18" drag radials that hook much better than 20" drag radials.

Also, 26 lbs of rotational mass needs to be multiplied to equal static weight. (worth a lot more than 26 lbs as far as performance). Don't forget its rotating mass not just dead weight on the car.

So for the drag racers, dropping to 18" wheels is very beneficial.

[JusticePete]

Originally Posted by jrv2kgt-s

Thanks SSSoon for starting this informative thread.


On a side note. I just wish tire manufacturers (namely Bridgestone) release tire sizes that would better complement the maro. The available selection of compatible tire sizes and manufacturers for the camaro is pathetic...

For instance, I'm still trying to figure out a good road course tire for the camaro and the events I need the tires for has size restrictions. If I choose to go with what Bridgestone currently has available in the RE-11's, I am limited with the 285/35-19's. That works out to being almost 1 1/2" shorter that the factory tire sizes. A 285/40-19 or 285/45-19 would be perfect but they don't exist...

305/35/19/XLs on 19x10.5s

[SUX2BU]

Originally Posted by SGOS252382

I just know the drag racing guys save a ton of weight going to 18" wheels. Here's Padre's example using TSW Nurburgrings (which I run in 20").
Not the best road course setup (too much sidewall in his tire choices), but it puts wider tires up front and back. For drag, an even skinner front tire would be better.

TSW Nurburgring 18x8 (35mm offset), 18x9.5 (40mm offset), matte gunmetal
Nitto 555, 265/50-18 and Nitto 555R, 305/45-18 - these maintain the stock height.

Fronts weigh 50.5 lbs each vs. 62.3 lbs stock.
Rears weigh 53.5 lbs each vs. 68 lbs stock.

104 lbs vs 130.3 lbs.
So that's a 26 lb reduction in rotational mass and the ability to run a 18" drag radials that hook much better than 20" drag radials.

Also, 26 lbs of rotational mass needs to be multiplied to equal static weight. (worth a lot more than 26 lbs as far as performance). Don't forget its rotating mass not just dead weight on the car.

So for the drag racers, dropping to 18" wheels is very beneficial.

For real weight savings you have to step down in tire size.
My street set up 18s are 66 lbs lighter than stock and my track set up 18s are 102 lbs lighter than stock.

[JusticePete]

Originally Posted by SSSoon

Did some digging, and am trying to get my head around the pros/cons of different rim sizes.

Michelin lists rim size as 10-11 inches for the above tire.

Forgestar has lightweight CF10, 20x10, that they list at 24.6 lbs.

Curious as to why you would recommend a 10.5" rim width over a 10" (or even an 11") and what the difference would be (driveability, sidewall flex, rim protection ...?)

Really appreciate your thoughts!

SSSoon,

The 10.5 will stretch the tire and give you great feedback. The ten very good, but not as good as the 10.5. The 11 stretches the tire tighter for a really crisp feel, but watch the pot holes.

[SSSoon]

Originally Posted by SGOS252382

I just know the drag racing guys save a ton of weight going to 18" wheels. Here's Padre's example using TSW Nurburgrings (which I run in 20").
Not the best road course setup (too much sidewall in his tire choices), but it puts wider tires up front and back. For drag, an even skinner front tire would be better.

TSW Nurburgring 18x8 (35mm offset), 18x9.5 (40mm offset), matte gunmetal
Nitto 555, 265/50-18 and Nitto 555R, 305/45-18 - these maintain the stock height.

Fronts weigh 50.5 lbs each vs. 62.3 lbs stock.
Rears weigh 53.5 lbs each vs. 68 lbs stock.

104 lbs vs 130.3 lbs.
So that's a 26 lb reduction in rotational mass and the ability to run a 18" drag radials that hook much better than 20" drag radials.

So for the drag racers, dropping to 18" wheels is very beneficial.

Yeah, I'm coming to realize the big differences in priorities for drag vs. road course. Tall sidewalls = good idea on the drag strip, but not a good idea for cornering. I guess that is why guys who are real serious have different rims+tires for each.

One of the reasons I posted the calculations I did up top was to try to figure out the true benefits of smaller rims. If you maintain stock height and go with an 18 inch rim, you have to make up the difference with rubber - in general, comparing within tire brand, the tires are heavier than those made for a 20 inch rim. So it seems like to make a good decision you would want to:

1. Find a light rim
2. Reduce overall tire height
3. Find a light tire

BUT, then comes the hard part - how grippy is the tire you picked? The wear ratings can tell you generally what is roughly comparable but it seems as though the best indicator of grippyness is to talk to people who have actually personally tried different tires and can offer firsthand evidence. And, even more important, have they tried using those tires for the purposes that you plan on using them for? Lots of tires get rave reviews for certain purposes - drag guys like one thing, track guys like another, some people are just delighted to get a tire that lasts a long time and seems marginally better than the Pzeros. It's probably obvious to many people but it took me a lot of digging to really accept that no tire can do it all.

One thing I wish I understood better is contact patch. Sure, a wider tire gives you more contact, and in general I think everyone agrees that is a good thing for performance applications. But beyond that, I wonder how much difference overall tire radius has on contact patch. Is a 26" or 27" high tire really different from a 28.5" high tire? Or, does it all really not matter much and the real thing that matters is tire pressure? I bet getting the right pressure to maximize contact patch is key. I wonder how you can tell whether you have the best tire pressure. JusticePete points out that getting the rim width right for a certain tire is also key to maximizing contact patch. Lots of variables.