I have a 1970 300SE L6.3 that I have a set of chromed OE 6.5Jx14H2 rims with brand new Dunlop SP Sport A2s and a spare set of alloys that are aftermarket OE-style Rial ADB65's (same size/design). The chrome rims are brand new and the Rials are an NLA discontinued series; so I have no interest in going to 15 or 16" rims.
I understand that although MB originally shipped the car with FR70VR14's which translated to 195/70R14's, MB now recommends 215/70's because there are no 195/70's with the recommended load rating.
My car is primarily for limited driving (under 1,000 miles annually and for car shows. I never car passengers or cargo and do not drive at sustained speeds over 100 but I would like to widen the "footprint" at the rear.

I have 195/70HR14's in the OE rim/ Dunlop set and the other Rial rims have almost new Michelin MXV4's in a 205/70HR14 size. If I measured correctly, a 60 aspect ratio tire around a 225/60R14 size should fatten the section width from 8-8.5" to 9-9.5" while maintaining an approx 24.5-25" overall diameter.

Do you have any experience as to the maximum width aspect ratio that will safely fit inside the wheelwells on the W109/8 with th OE 6 1/2 x 14 (30 offset) forged alloys? I would prefer to retain a 25" approx diameter overall and stay inside the fender flares as I don't want tire or body damage if my air suspension were to deflate (such as is likely to happen when changing a tire). What is the max. size/width that could be used?

Thanks ,
Brad-----