At what point is more tire "too much" tire?

[Rhino]

This is something I've struggled with many times during this build. I'm trying to finalize my wheel sizes, and am left wondering how much tire is honestly needed at all four corners. In order of precedence, I would have to rate performance over appearance.
For the wheels I've selected, I have two options in the front. 17x8.5 and 18x9.5. In the rear, I'll be running 18x10.5. I've been planning somewhere in the neighborhood of a 285/295 in width.

I'm torn between my two front options. I'd like to run 18's all the way around, for appearance, but don't want to find myself limited by the 8.5" wheel. With the 8.5" wheel, I'd be looking at a max of 245 for a front tire. Am I giving up a lot by limiting my front to 8.5"? I've grown rather fond of the 275/40 R17's on my 4th gen SS, and feel it may also be a good selection for the front of my '68.

As far as the rear is concerned, I do like the steam roller look of 315's/335's in the rear, but I have a hard time believing they would perform much better than a 315 or even 295's in most situations. I have a feeling some of the cars we see running around with fat tires are making up for a lack of proper chassis tuning.

[HILROD]

I'd say it's personal chioce mostly. The real large rear tires seem to me to be a kind of Pro-street look. I like it but without the power to back it up, handling can be affected. The front tire size can be limited by the ride height of your car. I went with 8 inch wide in front and get minor rubbing inside at full lock and have no room to go out. The rear has 315s and I need more tire back there. I did have to add a rear bar to keep the car flat with the bigger rear tires.

[parsonsj]

Most folks believe 50 mm is the most difference you can allow on tire sizes (front to back) and still have good handling.

See here (https://www.pro-touring.com/forum/showthread.php?t=52405&highlight=rear+tire+width).

And here (https://www.pro-touring.com/forum/showthread.php?t=38698&highlight=rear+tire+width).

And here (https://www.pro-touring.com/forum/showthread.php?t=35365&highlight=rear+tire+width).

And here (https://www.pro-touring.com/forum/showthread.php?t=27824&highlight=rear+tire+width).

Search is your friend.

jp

[parsonsj]

Oh, and over on CC.com, they've had this discussion on the subject:

http://corner-carvers.com/forums/showthread.php?t=22831

jp

[Vegas69]

I'm running a 255/40/18 on a 8.5 rim. That is exactly what it's spec'd for.

[TT302Z28]

"At what point is more tire "too much" tire?"

When they rub!

[JRouche]

"At what point is more tire "too much" tire?"

When they rub!

And that pretty much sums it up. If you are performance orientated then the wider tire wins. In all cases. Fit what you can. But you have to measure the fitting before hand. JR

[Rhino]

That is a lot of good info. Thanks.
I must have been really tired when I posted this initially. What I had meant is that the sizes were 17x9.5 and 18x8.5. I'd love it if they offered an 18x9.5, although they don't.

That's just about made up my decision that I'll have to go with the 17 fronts. After some reading, and a little further thought, I think I'll be going with the 275 front.
If anyone else is potentially looking to go with a 17/18 stagger, here's a thread I found with a few good pics. https://www.pro-touring.com/forum/showthread.php?t=33680.

[parsonsj]

If you are performance orientated then the wider tire wins. In all cases. Fit what you can. Not quite. For road racing, the balance between the front and back matters. Too much rear tire makes a car push. For optimum road handling, put the biggest tire you can on the front, and the same size or slightly bigger (no more than 40-50 mm) on the back. For more information, have a look at the links I provided above.

jp

[Vegas69]

I personally hate tire rubs. A 275 is going to rub on the inside of a 68 unless you have an aftermarket frame or steering stops.

[Chevy]

I personally hate tire rubs. A 275 is going to rub on the inside of a 68 unless you have an aftermarket frame or steering stops.

Vegas is right, i have the stock subframe in front with DSE coilovers and i get a little bit of rub on full lock-out turning even with 245s.

Good luck with your project!
Paul

[Roadrage David]

I have 265 in frond and 315 in the back.
.Perfect combination with the 3.42 rear ratio the 0.67 overdrive and the 530 hp/577 lbs torque. subframe con , all the good stuf. i have a hard time trying to get the rear to swing out in hard short corners. no rubbing in frond just tire contact when i go fast over a dent in the road.

[BonzoHansen]

Not quite. For road racing, the balance between the front and back matters. Too much rear tire makes a car push. For optimum road handling, put the biggest tire you can on the front, and the same size or slightly bigger (no more than 40-50 mm) on the back. For more information, have a look at the links I provided above.

jp

Just to go along with the balance comment, but in more backwards example, didn't GM recently (past 2 yeras or so) put slighty wider tires in the front of one of their 5.3L FWD cars just for better balance? I remember something about that.

[MarkM66]

"At what point is more tire "too much" tire?"

When they rub!

Agreed.

Unless you're racing, go for what looks good.

[Flash68]

I personally hate tire rubs. A 275 is going to rub on the inside of a 68 unless you have an aftermarket frame or steering stops.

yeah I am likely looking at steering stops since I am going big with the 275. aw hell, who needs to turn? :machine: