How do I know how big of wheels I can put on my car?

I have a 1999 Mercury Sable. I want wider tires on my car. I know I need to change the rim but how big can I go without any problems?How do I know how big of wheels I can put on my car?If you want a true answer just call: tirerack.com toll free @ 888-541-1777. They sell aftermarket wheels and tires for a living. They'll advise you what plus sized widths, diameters and bolt patterns that will fit exactly, no guess work on your part. They'll also know what plus size tires you can use that won't screw up your speedometer.How do I know how big of wheels I can put on my car?take it to a car fixer place and ask them.How do I know how big of wheels I can put on my car?I have a 1996 Mercury Sable. You may want to ask a mechanic. I was told I shouldn't change the rim size on my vehicle. Either way my Sable is a piece of crap and I bought it a couple years ago with less then 60,000 miles on it.How do I know how big of wheels I can put on my car?Hi you can put the rim size you like but you might need hub rings and maybe spacers , but you can put any rim size you like , but remember the tire size is important it must be 35m or up to 40m ciao for now.