Max tire width for PP wheels

[kn7671]

Look at it this way guys, Ford (and all other auto manufacturers) knows that putting 295, 305, or 315's on a car requires the appropriate wider than 9.5" wheels.

The 2015 GT350 will have the following wheel widths and tires:

Front = 19" x 10" with 295/35ZR19's
Rear = 19" x 10.5" with 305/35ZR19's

The 2015 GT350R will have slightly wider wheels and tires:

Front = 19" x 10.5" with 305/35ZR19's
Rear = 19" x 11.0" with 315/35ZR19's

If simply adding a 10mm wider tire to the "R" model was sufficient on the same width wheels as the base GT350, than they would have done it, but obviously a 10mm wider tire necessitated a 1/2" wider wheel.

I don't know about you guys, but I personally want to know that my tire actually fits the wheel being mounted on. If you've ever looked a tire while off the wheel, and and inspected the tire bead (where the tire mounts to the wheel), you will see that the sidewalls can only be pulled in or pushed out so much before the tire mounting area changes angle, preventing a solid and flat sealing surface between the wheel and tire.

Driving a car hard with into corners leads to tire deflection. Greater amounts of deflection lead to unpredictable handling and grip. Watch this video (around 30-seconds in) and watch the deflection at moderate speeds in a parking lot. I don't know the specific of wheel/tire width in that video, but imagine trusting your OverSized tires to remaining properly mounted on the wheels into a corner at 85mph. It only takes one tire dismount or blow-out at the wrong time to possibly change your life, or others if it leads to your death.

[ame]

Simply put, NORM is right. If you want wider tires, than get wider wheels. Check the tire manufacturers approved wheel width for each tire size.

Here is another video that talks about tire deformation, heat, blowouts, and tire pressure. The video is relative since installing too wide of a tire on a wheel induces very similar characteristics.

[ame]

Sponsored

 

[s4-to-15gt]

cheers to Norm for making sense to everybody.

 

[VTECSAUCE]

Just wait until the stance guys start getting a hold of these cars. Norm's gonna blow a gasket. Norm, as much as I agree with you about function/form, you're not going to win that battle. TBH, I don't understand why you exert so much effort into the topic. Once you start seeing 205's being stretched over the stock wheels you're gonna have an aneurism trying to convince those ppl its dangerous. LOL Let nature handle them.

 

[Norm Peterson]

It isn't about winning or losing a battle or argument. I have no emotional content at stake here (I'm a retired engineer and don't react that way).

It is about getting people to understand that tire and wheel sizing is really a technical matter, and that once you step outside established guidelines these technical considerations really are more important than subjective opinions concerning either appearance or financial inability (reluctance?) to do it up right.


FWIW, I don't like the Euro-stretched approach any better than the "let's squeeze as much tire on a narrow rim as we can" that's still more prevalent on this side of the pond. You might (with the proper reasoning and caveats) get me to agree to wheel widths half an inch outside recommended, but that's as far as I'd ever go. With emphasis on "proper reasoning and caveats".


Norm

Sponsored