Wheel / tire sizes

I know it's out there somewhere....can anyone help me find it ?

SL's of different years had different tire/wheel configurations.

My 84 500SL Euro came with 14x5.5" mags while the very next year SL in USA had 15"....virtually the same body layout.

I want to find a conversion chart to see what the possibilities are. I know someone has tried fitting 20" wheels on these cars  .   I don't wish to go that far or that expensive, but I would like ot dress this old gal up a little. 15"-16"-17" ?

What would the backspacing need to be ? What tire size will fit the wells, not rub in a hard corner and keep the law off me (due to Speedo not being accurate) ?

 

Seven Months and no responses ... thanks

If anyone cares, there are a couple of Wheel manufacturers out on the net that
provide good information, but there's nothing like a wheel man that wants your
mercedes toy dollars and will fit up anything you like to see if it works. (yes of course
they will start near standard height/width and go through full supension motion to see how far they can go). I appears that 17" x 7" with the right tire is as "big" as you can
go on this body style (suspension parts need to be near perfect though).