[2SS Capt]

Originally Posted by arpad_m

305/25/20 is a bad idea no matter the price. It's much shorter than stock, so your speedo will be way off (showing 70 mph at 65 mph, for example), it has very little sidewall, so the ride will be worse, and even more importantly, it's much wider than stock and you still have the stock 9.5" rear wheels, so the already miniature sidewall will be smushed out, I'm not even sure the bead will hold well enough under these conditions. It is true, however, that you can pair them with (similarly compromised) front tires that will avoid the ABS and Stabilitrak errors someone already mentioned.

In summary, if you want wider tires, you need wider wheels. The SS 1LE has the following setup, and for good reason:

Front: 10.0" wheels, 285/30/20 tires
Rear: 11.0" wheels, 305/30/20 tires

You can go slightly wider on these, maybe 10 mm extra each end, but even these wheels aren't on the widest side for real steamroller tires (think about the ZL1 1LE that was given 12.0" wide wheels for its 325/30/19 rears).

Also, I checked prices on 305/25/20 tires, quality brands aren't cheap in this size, so I'm afraid you might have seen some absolute crap with that good deal, which, if true, you should avoid regardless of all the wheel talk.

I agree with ALL of this, this size you are looking at (305/25/20) is not a common, nor recommended size... If you want to run 305/30 or 315/30's on the rear, you really should buy 11" wide rear wheels to safely run that width of tire... If you want to run 275-295 up front, you really should be running 10" wheel widths... You run anything less than this for these tire sizes and you are really risking a tire "rolling" off a rim, losing pressure or any other catastrophic tire event... If you can afford the car and want wider tires, please make sure you can afford the appropriate wheels to safely support those tires (MRR017 1LE replica wheel that are 10.0" up front and 11.0" in the rears are only about $1600, much cheaper than a lawsuit when you blow a tire and crash into a family, and they look a HELL of a lot better too!)

Be smart about it, wider tires are great, as long as they have the wheels to safely support them!

My 2SS with MRR017 wheels and 285/30's up front and 305/30's out back (10.0" and 11.0" respectively)

[Frankyp209]

*Update*

So yes they fit. 305/30 on 9.5 stock wheel. No rubbing. No stretching. Or mushroom looks flush and fits great. Check out the pics.

[david_acm]

It looks noticeably smaller. I still have stock 245s in the rear and they're not that deep inside the well. Is it just me, or some optical illusion, or are they small (width-wise)? They're definitely smaller in diameter but 305 width usually fills that rear wheel well pretty decently no?

[Frankyp209]

Hmm. Not sure. It’s a 305/30/20. Pirelli. It’s really deep. I mean it has a mean stance now from behind.

[FlukeSS]

Originally Posted by Frankyp209

Hmm. Not sure. It’s a 305/30/20. Pirelli. It’s really deep. I mean it has a mean stance now from behind.

I have 305/30R20 on the back as well.

They look fine to me, the other person has 245's with a higher aspect ratio than these 305's so his fills out the well more vertically. Of course with a lowering spring package that will likely change.

[DevilsReject97]

Originally Posted by david_acm

It looks noticeably smaller. I still have stock 245s in the rear and they're not that deep inside the well. Is it just me, or some optical illusion, or are they small (width-wise)? They're definitely smaller in diameter but 305 width usually fills that rear wheel well pretty decently no?

305s are going to be significantly smaller looking compared to a 245. However, that's due more to the tire wall generally being smaller all together on a 305 anyway.

Typically, both the 5th/6th gen cars have run a 245 on the front wheel and generally a 275 on the rear (ZL1s/1LEs not included). Most of the V6 models run a 245 on front/back in many cases as well for the 6th gen, depending on the wheel/model.

[SamSmoothCastel]

Originally Posted by Frankyp209

*Update*

So yes they fit. 305/30 on 9.5 stock wheel. No rubbing. No stretching. Or mushroom looks flush and fits great. Check out the pics.

whats on the front. can you take a full pic??

[david_acm]

My comment was regarding the width. I understand the sidewall and diameter of the tire that OP chose are smaller, however the width (305) should remain the same across all tires, no?

It seems like the wheel is further inside the wheel well than normal. I brought up my 245s because I believe they're the skinniest wheels you can get on a 6th gen, but even they don't appear to sit so deep inside the well.

This 1LE's 305s shot from a similar angle seem fill the entire rear wheel well and are almost flush with the body lines of the car.

[DevilsReject97]

Originally Posted by david_acm

My comment was regarding the width. I understand the sidewall and diameter of the tire that OP chose are smaller, however the width (305) should remain the same across all tires, no?

It seems like the wheel is further inside the wheel well than normal. I brought up my 245s because I believe they're the skinniest wheels you can get on a 6th gen, but even they don't appear to sit so deep inside the well.

This 1LE's 305s shot from a similar angle seem fill the entire rear wheel well and are almost flush with the body lines of the car.

That's due to the offset on the style of rim.

[Frankyp209]

Here’s a side shot. I have the stock redline wheels. Front 20x8.5- Rears 20x9.5
Front tires 295/30- Rears 305-30. And yea I think it’s the offset that keeps them flush. No rub at all. Also, it’s a V6 so no mag ride. I have 1.4” lowering springs on it.

[BatMobileLT1]

Originally Posted by Frankyp209

Here’s a side shot. I have the stock redline wheels. Front 20x8.5- Rears 20x9.5
Front tires 295/30- Rears 305-30. And yea I think it’s the offset that keeps them flush. No rub at all. Also, it’s a V6 so no mag ride. I have 1.4” lowering springs on it.

It sounds like you are happy with this combination, however note that from Tire rack specs:
Front: 295/30/20 – on 8.5” and should be on minimum of 10” (and up to 11”) - wheel is 1.5” too narrow
Rear: 305/30/20 – on 9.5” should be on minimum of 10.5” (and up to 11.5”) – wheel is 1.0” too narrow

and you should try googling "issues with too wide tires on narrow wheels" as there is information that it is both unsafe and that you won't get good handling from it.
Such as: https://www.rimringz.com/tire-too-wide-or-too-narrow/
and one site listed that too narrow a wheel may make tire taller and narrower when it is inflated which might explain why your tires look recessed into the wheel well?
Best of luck if you stay with this - just others should be aware of the issues.
And as others have posted on this thread, the tire sizes you picked should work fine if you put them on 1LE sized rims of 10" front and 11" rear.

[Frankyp209]

I am pretty happy with the combination. I am aware of the issues and all the concerns. However, I am not racing taking it to the track or hard cornering it. It’s a daily so to work and back home. And it has a good stance right now. Purely cosmetic lol. But I appreciate all the info. I have my original set up ready in case I need to make a swap.