Concorde LXI wheels.
So I score a nice set of silver powdercoated, 16" Concorde wheels with barely used Goodyear 225/60/16 Vivas for my '95 88. They bolt right up and some minor rear wheel wheel lip bending assures no rubbing. Dramatic difference from the OEM alloy 15 inchers. Have the wheels/tires balanced before a major road trip. Annoying vibration at 55-60 and again at 74-78 mph, anything above 80 and no vibration. Have em balanced again halfway thru the trip with no improvement. ALL front end components are either new or in great shape. No ball joint looseness, no worn bearings, tie rods are new and tight as is the steering rack. New struts, and sway bar bushings. Alignment is dead on. So in short, the front end is tight. I checked for runout on all four wheels with a dial indicator, none. Tire wear is dead on even on all four wheels. Figureing the Walmart Vivas were the problem, I went back to Discount and told them of my problem. We pulled all the wheels off and ran them on the balance machine with the weights still on them. Couple tires less than a 1/4 off and they corrected that, (for free). The guy is telling me the Concorde wheels have a different bolt pattern from the Olds/Pontiac spec, 5x114.3 for the Chrysler wheels and 5x115 for the Olds and this could be causing the vibrations. Not much difference between 115 and 114.3, or is it? The lugs are conical and I cannot see how the rim would not/could not be centered when the lugs are tightened to specs. (Runout was checked with the wheels on the car). I have another 2600 mile road trip coming up next week and I do not want to endure another ride in a paint shaker or worry about a cop over the next hill 'cause I have to "drive out of the vibration zone". The vibrationis enough to buzz the mirrors and keep the seats vibrating like a cheap motel vibrating bed. I have the funds to buy the correct (and similar looking) 5x115mm wheels but do not want the spend the money unless I have to. Your thoughts gentleman?