Why can't you just get the proper speedo gear for whatever wheel/tire you are running? I believe they still have the plastic gear even with the computer. I thought you could change the gear and keep the speedo should read the same. Or did they make it a more complicated computer thing? If the factory offered the size you are adding they must have the right set up somewhere. The difference in speed to the speedo will be proportionate to speed, so it won't be much around town, but when you get up to 70+ it can be considerable. If you just want to add bigger rims, you could go "plus 1" and just get lower aspect ratio tires, keeping the same diameter. That won't throw off your speedo, but you'll lose some ride quality (and gain some handling) I'm surprised 90s Imperials came with 14s. All my fwd mopars (80s Daytonas and Lasers) had 15s _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail