Wheel fitment

Perhaps this chart will help. It contains offset info.

Its brand new, not quite the same as what I posted a month ago.

I think the wheel/tires you've selected look good. The offset/back spacing will not work however.

OEM 8" and 10" Campi's both have 5-1/4" backspacing. Back when tires were available, I knew Pantera owners who had aftermarket wheels made in the same sizes with 5 1/2" backspacing and they were fine. I wouldn't use any more backspacing than that however, in the widths you're talking about. Be aware, altering the track width at one end, relative to the other, can drastically effect balance. If you know what you're doing, you can alter the track width to improve handling but if you don't, stay as close to tried-and-true wheel and tire specifications as possible.

Why not just bite-the-bullet and buy a set of 17", 18" or 17"/18" Campi clones from one of our Vendors? How much can you really save by buying a cheap set of generic wheels that aren't made for a Pantera. It can't be that much; certainly not a significant amount. Most of the Campi clones are far less expensive than high-end three piece wheels like HRE, Kinesis, Forgeline or ADV-1.

George, Thanks for the chart. You always seem to have a numbers based solution. It seems like the wheels should fit, but they may be more recessed into the wheel well than I would like. Generally, ~2.7" of wheel extends from the hub to the fender, based on the front backspace listed. My selection of wheels would have 2.3" inches extending from the hub. In the rear, wheels listed in the chart extend ~4.75" from hub to fender and my selection would extend 3.7". Am I doing the math right?

David,
My choice to go with cheap and generic wheels is based on the following logic.

1. Cheap and generic wheels are ~$1000. They can be changed easily down the road as tastes change.
2. Campi clones in 17" are ~$2000. With only 3 matched tire selections, there is a possibility that these wheels are obsolete in a few years. Seems like it could be throwing 2k down the drain.
3. Campi clones in 18" are ~$4000. It seems like a boat load of money for a set of wheels. I may also not be your typical Pantera owner. I saved for years to afford my new toy and 4k for wheels was not part of the budget. Could I afford them if I wanted to save some more, yes...Do I really want to...no. Many competing priorities (body and paint, engine refresh, interior)

Jim

The distance a tire/wheel combination extends outwards (compared to other tire/wheel combinations) can be computed with this formula:

(tire cross-section ÷ 2) - off-set

This defines where the edge of the tire's sidewall is in relation to the hub. That dimension should fall in the range of 102mm to 112mm up front or 149mm to 159mm in the rear or the tire shall rub the fender arch. The outer sidewall limits can vary by 10mm due to tire diameter, ride height, camber adjustment and whether or not the fender arches have been “rolled”. I prefer to use the conservative limits 102mm (front) and 149mm (rear) as my limits, because I like "wiggle room".

check out the latest posts on the last page of sticky #8 for a detailed explanation.

Going in the opposite direction, if you stuff the front tire/wheel too far into the wheel well it just won't look good and it won't match the rear tires which are rather limited in where they can be situated within the wheel house. Stuffing the front tire inward reduces the track width (which reduces cornering traction) and alters the scrub radius too.

In general 18x8 wheels for the 225mm front tires will be fine with 12mm off-set unless the car is going to be lowered beyond the European ride height. The factory front 15x7 wheel off-set was 6mm. 12mm off-set will reduce the factory track width by 1/2 inch. This is better however than the 18mm off-set of the factory 15x8 wheel which is popularly used as a front wheel.

The way I like to proceed is to increase the amount of front tire offset as little as possible, in order to maintain the front track width as wide as possible. Then recess the rear tires to match the front tires if possible. The problem however, there's minimal opportunity to adjust the position of the rear tires. For instance tires 26.6 inches in diameter or more run into the issue of possibly rubbing the mufflers on their inner edges. 18x10 or 19x10 wheels for the 285mm rear tires are therefore limited to -6mm to zero off-set. -6mm is the factory dimension for the 15x10 wheels. That off-set extends the outer edge of the 285 tire close to the edge of the fender arch and increases the rear track width by 2 inches. Zero off-set of the rear tires recesses them by 6mm (1/4 inch). Rear track width is still 1-1/2" wider compared to the track width using the factory 15x8 wheels. At zero offset, a 285mm tire should have 1/4 inch clearance on either side, with the muffler on the inner sidewall and with the outer fender on the outer sidewall. In other words the tire is centered between the muffler and the outer fender.

The front tire's sidewall should be about 15mm recessed inside the fender, and the rear tire's sidewall should be about 8mm recessed inside the fender. Not a bad match, better than a lot of tire/wheel sets you'll see on Panteras. The front track loses only 1/2" width, the rear track gains 1-1/2" width. Both help the Pantera stick in corners. The tire diameters will be in the ball park allowing the chassis stance to be set properly (level) while the front and rear tires are equally centered within the wheel arches. No clearances are being pushed to the limit, everything has a little "wiggle room". In other words, you've got a combination there in which both the chassis' engineering and the car's appearance were taken into consideration.

George, between this post and the latest post in sticky #8, I think I have it. I'll resume the search, but this time with numbers that I can actually use. Thanks.

In general, narrowing the rear track width, relative to the front track width, will decrease traction at the rear. The only way you can get your 18" wheel combination to work is with a set of custom, hubcentric spacers, that will convert the wheel's offsets from incorrect to correct. When using spacers, you should also change to stronger 1/2"-20 studs. When you add the cost of spacers and studs to the cost of the wheels, you'll find the Campi clones are not that expensive. If you can't afford them now, just wait until you can.

Also, when choosing tire sizes, try to stick with sizes that are (or were) OEM on something. That way, you should always be able to find tires. Stay away from "tuner" tires. As an example, I think it will be a long time before 335/35-17's disappear. After all, they were OEM on the Dodge Viper for many years. There might only be one company that makes them but at least there will be one!