What are we arguing about here? I see some good math being done here, haven't taken the time to read most of it but I hope this is being constructive to the thread. I would hate for the inexperienced end user to vear from the guide. This guide is based on physical fitments that we had done in the early stages of the 3rd gen wagon and sedan.
I don't know if this has any relevance to the argument. But I will repeat some basic information that should be throughout this thread. I will list a few fitments quickly with regards to some speed reading I did above.
The sedan has about 3mm more front spacing than the wagon. I'm sure you're all aware of that by now. Now the guide is based on an unmodified fender. There is a good amount of fender lip on the P5 near the front and rear of the "rear" fender wells. This however does become very thin at the center of its arc, therefore in my eyes viewing it as a huge liability i.e. cracked paint, etc...
From this my physical work came to the conclusion, with most brand tires, that a 17x7 +42 was a good tolerance for a 215/40/17 on the NA models sedans. I felt that this tire provided maximum contact patch in near stock diameter and available in most popular and unpopular tire brands. Now for a wagon that became a +45 on the 7" width. Keep in mind tire flex as well, also the way a tire may stretch on a specified width will also change other dependent values.
For a 7.5" wide, +45 on sedan, and +48 on the wagon. Retaining the 215/40/17. With the wagon we were able to run a 205/40/17 on a 7" +42, but to me this was not ideal. I did not like the asthetics nor the deviation from the "ideal".
If one wanted to run a 225 on a 17" wheel the closest to stock NA diameter would be a 225/40/17. Now the problem with this tire size is that it's extremely limited in selection. One is the Nitto NT555, I've had them, the other is the Wanli, decent and cheap. Neither of the two in my opion are extremely performance oriented. Trust me I've tested both. This is why I move to the 215/40 or 215/45.
I have a wagon and since it's boosted I've opted to run a 215/45/17 to assist in my gearing. I have all 7.5" +48 wheels. With this tire size the only area I "grabbed" was the front portion of the rear fender well. Where it comes down towards the side skirt.
The world challenge cars ran a 225/45 T1S with a 17x8 +45. The backspacing isn't the issue with our cars as much as it is the front spacing. These cars had heavily modified fenders.
With regards to the majority of Macpherson strut style suspensions the "wheel" will camber in more upon compression of the damper. I have not needed to take any of this into consideration since we decided to say "Screw it, let's just buy a bunch of different wheels/tires and test them out." We ran touge, messed up streets, downtown areas, etc.... Based on that we were able to determine what the "safest tolerances" are.
Anyways, if you want to email me
sales@autornd.com I can try to answer any questions based on my personal experiences with the 3G chasis.
Later guys. Don't forget we can always start a wheel fitment debate thread. Let's try to keep this clean. I know there are guys here that have continually been supportive of the community in my consistent absence. I would hope that they are very highly respected. I do quite enjoy the mathematics being displayed. It makes me happy to know that there are people who find this easy. The only problem is that these aren't ideal physical situations. There are many unaccounted for variables. I do see some serious detail but honestly we can argue about math all day long. It all comes down to simple testing and survey. Take an average and see where the we all fall. There will also be minor variations from chasis to chasis. No two are identical. Shoot every protege5 will have less front spacing on one of the rear fenders than the other, therefore causing it to rub.
Peace, Rishie
