245/45 x 17 and 255/40 x 17, slightly ticked and confused

[Project TNX]

So I got my tires mounted on my SLP ZR1's yesterday and I notice the wheels with the 255/40's sit a 1/2 inch lower than my 245/45's. The thing is, I couldn't find any 255/45 x 17's in the tire I wanted, and since the 40 and 45 numbers represents a percentage of the sidewall vs. the tread width, I figured that the 40 just changed with the 255 to keep the same heigth.

Everything looks great though, and I have my car up on jackstands so I don't have pics yet or know if it will look wierd or not.

For those that have wondered about the SLP wheels, the distance from the edge of the tire to the back of the wheel hub is 4.5 inches, so I am optimistic I won't need to add a spacer to fill my wheel well out.

 

[SouthernCal GN]

The math works out....
the 255s are 25.03" tall, 10.04" wide,
the 245s are 25.68" tall, and 9.65" wide.

A 265/35R17 would be 25.35" tall, 10.43" wide, very close to your 245s height, and wider than the 255s.

HTH

 

[BlackMetal]

Makes sense based on the tire sizes.
Overall Diameter: 25.68 in 652.27 mm

Overall Diameter: 25.03 in 635.76 mm

How wide are the rear wheels? 4.5" backspacing might sit a little too far under the car depending on how wide they are.

 

[Project TNX]

Makes sense based on the tire sizes.
Overall Diameter: 25.68 in 652.27 mm

Overall Diameter: 25.03 in 635.76 mm

How wide are the rear wheels? 4.5" backspacing might sit a little too far under the car depending on how wide they are.

With the GNX flares I'll be running I'm almost guaranteed to have to kick the wheels out 1.5 inches or so, which is fine by me, I was expecting that actually. I want an aggressive stance, but at a regular ride height, I will not be lowering my car.

That 1/2 inch difference is very noticable when the tires are side by side, hopefully it won't be noticable at all when I have them all mounted.

 

[UNGN]

275/40's to me would be the best 17" rear tire size.

 

[Project TNX]

275/40's to me would be the best 17" rear tire size.

They would look nice, and they may be my next size, depends on how she handles with the 255's though, you can't beat $70.00 per tire. Of course they are probably going to suck out of the hole, but the Sumitoma HTRZ's had a good review on tirerack.

Thanks for the help guys, I'll post some pics later in the day.

 

[xcessiv6]

Why would you put a shorter tire in the back than the front, did the tire store not tell you that. Go with atleast 26" tall on rear a255/50/17 is 27 inches tall which is a good height for a GN

 

[Project TNX]

Why would you put a shorter tire in the back than the front, did the tire store not tell you that. Go with atleast 26" tall on rear a255/50/17 is 27 inches tall which is a good height for a GN

That is why I am slightly ticked, I didn't want a shorter tire on the rear.

There is no tire store, just me and the tirerack.com.

 

[Tom Tom Turbo]

245/45/17 BFG Gforce T/A on 17x8 SLP with 4.5" BS....no rub, fits pretty well, but I would like them sticking out a little bit more. Looks freakin sweet though!

 

[Tom Tom Turbo]

here's one more shot, but the quality sucks

 

[Project TNX]

here's one more shot, but the quality sucks

Nice, here is the adapters I intend on running, fill out the wheel well a little more since I will be running GNX flares.

- Skulte Performance Designs

 

[mjdwyer23]

Nice, that's what i was gonna do before i got indecisive and bought a new car. Do you have any pics? Did you do the polished or the black ones? I was thinking about doing the black ones with the polished lip.

 

[Tom Tom Turbo]

the pics above are of my car with the hyper black ZR1s....when the light hits them right during the day, they look almost chrome, but after dusk, they look gunmetal. Pretty slick I think.

 

[Project TNX]

Nice, that's what i was gonna do before i got indecisive and bought a new car. Do you have any pics? Did you do the polished or the black ones? I was thinking about doing the black ones with the polished lip.

I have what is in the pics. They look a lot like the jet hot coating in direct line, but have that black pearl look to them.

I have always thought the ZR1's were the best looking domestic mag ever made, and with the correct offset for our cars, they are ideal.

There is no harder car to find the right wheel for than a G-body, very difficult to get the right look and combination to compliment the lines.

 

[BlackMetal]

Nice, here is the adapters I intend on running, fill out the wheel well a little more since I will be running GNX flares.

- Skulte Performance Designs

You are aware that the GNX flares don't actually give you any more room, right? It's just a cosmetic upgrade, the original fender will still be there and will still rub on the tires if you let them stick out too far. Unlike a real GNX where they trimmed the fenders and then flared them...they actually have more room for wheels.

 

[Project TNX]

You are aware that the GNX flares don't actually give you any more room, right? It's just a cosmetic upgrade, the original fender will still be there and will still rub on the tires if you let them stick out too far. Unlike a real GNX where they trimmed the fenders and then flared them...they actually have more room for wheels.

Uhhh, yeah, I am aware of that. My wheels are already a tad to far in for the aggressive stance I want, not like I am talking about smacking them past the body panel like they did in the mid to late 70's. I'm talking about filling in the wheel well here. I'll post pics of the entire before and after sometime in the near future so you can see what I am saying.

 

[at7we2]

here's one more shot, but the quality sucks

digging up an old thread here, but do you have any pics from the rear of your car with the 17" ZR1's? I'm thinking about getting a set of those or possibly another style with the same size and backspacing. It looks like the 4.5" backspacing is too much for an 8" wheel. It would be perfect with a 9" wheel. Just curious to see what it actually looks like from the rear.

Thanks,
Rob

 

[Tony_SS]

Like others have said. the 255/40 is a 25" tall tire. Don't kid yourself, It WILL look odd having a shorter tire in the rear compared to the 25.7" tall tire you're running up front. Your best bet, on an 8" rim, would be to go 255/45 for the rear. That is a 26" tall tire and is a common size and will compliment the 245/45 fronts nicely.