Since I've just installed 17" wheels on my 82' Avanti II I will pass along what I found. The fronts will tolerate a 17 x 8" wheel with a backside dimension of 4.5" (13mm offset). The tire I used is a 235-45-17" Bridgestone. In the 500 miles that I have driven it I can say that the ride quality is slightly worse over tar strips, the front end is more affected by bridges in the pavement now and any play or wear in the king pins/ steering linkage will show up as darty behavior. WARNING! The stock wheel lug studs have a knurled section that extends above the wheel face and causes the wheel to bottom out on the knurls before it is truly tight. Make sure that you chamfer the backside of the wheel to clear the knurling! If not done the wheels will come loose! Mount and tighten the wheels one at a time and then remove and inspect the back of the wheel for stud interference. The marks will be quite visible. The rear wheels are 17x9" with 6" backside dimension and a 255-45-17" Firestone fits just fine. I did sand the fender lips down to 3/16" just above the center of the tire to prevent rubbing. The tire sizes were determined by using the same diameter tire as a 1986 Monte Carlo SS and the appropriate Monte Carlo SS speedometer gears in the transmission. (I have installed a 3.73 TruTrac diff. same as a Monte CarloSS) The pictures of the car are on Egroups or I will post one to individuals if they would like to see the wheels. Andy Jones jones.775@osu.edu --------------------------------------------------- Ride quality is very subjective and I am personally one that prefers comfort. My experience has been onmany different cars that I have inspected that have been changed to 16"+ wheels is that the ride quality suffers greatly. One car that comes to mind was a newer full size Mercedes with 17"s that rode like a truck and also had very poor tracking. I find "wandering" a problem too when people switch to wider tires which is usually automatic when they switch to the 16"+ wheels. I don't know, just some more info to confuse you. Paul Katson paulkatson@inspectacar.com --------------------------------------------------- Going from stock to wider rims, tires, etc... Even though the weight of the car is distributed evenly across the rim, the total force at each wheel can be represented at the center of the rim which is normally not offset from the kingpin. As this distance increases (negatively or positively), the moment increases at the kingpin and spindle. This can cause a very noticable change in the ride, steering, and wheel bearing life, etc If you insist on wider rims, then the best (safest and/or logical) scenario is to match the offset of the original rim on the larger size. This splits the increase in width evenly over the suspension centerpoint. , IE, Magnum 500's (15 X 6) have a +15mm offset. This equates to 4 1/8" backspace. The replacement rims I use (16 X 7) are also +15mm and the added 1 inch of width puts 1/2 inch inside and 1/2 inch outside the suspension centerpoint, backspace = 4 5/8". Given the above and my experience with the install, I consider this to be the maximum rim width allowed to avoid frame interference on turns. If a 17X8 rim is used, like one of our counterparts has indicated, then I have to suspect that the mounting plane is much farther outboard from the centerpoint, which will haunt him (expensively) at a later date... BobJ (Nov 2000) jonroq@patriot.net -------------------------------------------------- I totally agree with you on the effects of putting wider wheels on a car. The stresses on a the bearings and suspension go up dramatically. Cars respond differently though. The modern econoboxes don't really like it. On the otherhand, on my 77 Bronco I added 4 inches (6" to 10" inch wheels) to the wheel width all to the outside 18 years ago (more telling 60,000 miles ago) and nothing has broken or worn out. Of course it's suspension is built like a brick s___house-triangulated Ford 9 inch rear (like NASCAR racer use) and suprisingly a Dana 44 front axle (just like our Avanti's but with steerable ends). I think the rear end of an Avanti will hold up OK but I can't vouch for the front end. It's American Iron so it probably will survive if it's cared for. Chuck Paras Nov 2000 -----------------------------------------------