I just got in my new Volk Sf Challenges and I have been reading post for a couple days now trying to figure out what tire size to go with. The fronts are 19 x 9.5 (+15) and the rears are 19 x 10.5 (-17). Along with posts I have been talking to the guy who will put them on for me. He said 295/30's and 245/30's because they are more common but he suggested 315/25's for the rear because it would give it a more square look and look nicer. If someone could give me their 2 cents on this it would be great. Also, if you have an opinion on what brand that would help too. The guy putting them on for me suggested continentals. Thanks alot.

 

Whatever tires you install, you should keep to the overall staggered diameter (height) front and rear.

Your car’s computer and its ABS expect a certain tire height on the front and rear:

• Front: 25.8" Overall Diameter
• Rear: 26.6" Overall Diameter

You should stay close to these values.

Tire width has these considerations:

• Do you prefer a stretched look, straight-up, or slightly bulged?
• Are you willing to roll your fenders?
• Do you prefer under-steer, or do you like neutral-steer (no one wants over-steer)?
• How much are you willing to budget for a tire purchase?
• Do you want comfort or is grip more important for your driving style?

There are many decisions you make before drilling down to a specific tire and tire-size.

BTW: Some tire sizes you mention are all wrong.

--Spike

 

Wow, are you sure about that rear offset (-17)???

The "normal" upsized tires are 245/35/19 and 275/35/19. Those fit, they won't rub with most commons offsets (+20 thru +25), and are widely available.

315 tires are way too wide for 10½" wheels. I also doubt you'd get them to fit on a Z without some serious fender rolling/pulling/mods or some camber adjustments - especially if you really have -17 offset wheels.

If your car has TCS/VDC, then you have to be extra careful on your tire size choices.

I'd suggest reading the Top 100 Questions thread, a lot of this is addressed there. You need to do some research in this forum before you start buying tires "outside the norm" because you will run into problems with fitting them.

 

Get a new tire installer, 315s are too big for a 10.5" wheel, and 19x10.5 -17 will not fit on our cars unless you run a 195 tire. I also don't like any model of the Continental tire. See what he thinks about Michelin Pilot Sport PS2s. I don't even think that 315/25/19 exists, not commonly at least.

Assuming the rears are +17, I would go with a more traditional set-up, like 255/35/19 front and 285/35/19 rear.

 

Thanks for the reply. As for your questions, I'd like a stretched or straight-up look, fenders are rolled and wide body kit installed, I'd like to keep the steering pretty close to stock, not really on a budget, and I want something in the middle of the comfort/ grip. It's a daily driver and not going to a track any time soon. I've been looking a little more and I think the PS2's or the Bridgestone RE050A's are the direction I am leaning. The size is all I am having an issue with. I keep reading post after post and everyone has a different opinion and every opinion has someone that says that it is no good. I'm just looking for some good solid advice. Thanks again.

 

Hey thanks for the reply. The rear wheel is in fact (-17) offset. Fenders have been rolled and wide body kits has been installed. Thanks for the link to the top 100 questions. There was some good info in there but, I didnt't really see a solid answer my particular wheel situation. As I am coming to find out -17 is definately an uncommon offset. So if you know anyone that has something similar that I could ask or talk to that would be very helpful. Thanks again.

 

To tell you the truth, I've never seen a negative offset wheel on a Z or G. Obviously if you've gone to the point of doing a widebody kit, you plan something really special.

My only advice would be to pick some tires that are close to the OEM outside diameters, so it will keep your speedo/odo accurate and have the correct stagger to prevent TCS/VDC problems. Other than that, you're going to have to do some digging to find a combination of tires that makes the setup look good and fits the size requirements that I mentioned.

 

With your widebody, you can safely run a 305/30/19, although that won't look stretched on a 10.5" wheel. Stretched tires and widebody seem like opposites to me given the 10.5" wheel. I'd think something closer to 19x12 with a 295 (stretched) would be more appropriate, but it's your $.

 

-17 offset with 315s hu....I sure hope you have a wide body kit cause that will not fit under a 350s stock body. You need something like +28 offset to fit 315s with a 10.5" wide tire.

maybe you can run -6 camber and fit that sh*t under the car lol.

In for pics of -17 offset rims

But to be real for a second...those rears are probably +17..even then depending on your camber and suspension you wont be able to fit 315s without Xtreme!! camber modifications...You might get 3k miles on a set of rear tires if you try and make it work.

 

Ok guys thanks a ton for all the inputs. I believe there is still some doubt on my ability to determine what size wheels I have haha. I need to run into work for a couple of hours but as soon as I get back I will post up some pics of the wheels and the car. Thanks again all of you.

 

Drifters

 

Ok guys here are some pics. They were taken with my phone so may not be the best quality but, should give you a good idea. I think I have already decided what I am going with but, let me know what you think. I'm thinking about 255/35 in the front and 295/30 in the rear. Wrapped with PS2's all around.

 

more pics

 

and more...

 

ya -17 offset is definitely gonna look nice with that kit. Good choice on tires

 

You should have started this thread with the pictures. Doing that would have avoided confusion and your thread would have received better advice from the onset. And... I wonder if you should have wider rear wheels?

--Spike

 

2nd. I would have likely gone wider also. You won't get much stretch with the 295s on a 10.5" wheel, especially with a PS2. I think that's a good thing, though I'd likely run a 305/30/19 PS2 on it coupled with a 275/30/19 or 285/30/19 on the front.

 

Front tires are taller than rear.

 

^^ David,

Good observation. Dave mentions poor overall diameter and faulty tire selection is his early reply and follow-up replies. Other people replying make this comment as well.

Question: Considering the OP’s wide body setup (which looks great)… What do you think about his wheel selection (wheel width and offset)?

--Spike

 

Davidv,
Thanks for that info sheet. I'm not exactly sure what that will change as for performance. I'm now garage guru by any means this is my first real project so I'm still trying to learn. I can't attach the spreadsheet I used to get my numbers but, here is a link to it http://www.tyrestretch.com/files/Tyr...or_English.xls By looking at them it didn't seem that there would be much of a difference. So would you suggest that I go with a 30 in the front also, or 305 in the rear, or maybe both. If, I put a 30 instead of 35 on the front I will have a rear which is bigger by .94" (stock is .39"), would that help out. I'm up for any advice you have. Thanks again everyone for all the tips!