sorry if its a new guy with same old question. i just bought a 1995 volvo sedan 850 here in Manila. it was originally purchased here by some rich senator and has been kicked around since then. I am the brand new owner and I have inherited a few issues that I will try to sort out.
the first issue is tire size.
it currently has 195/60 with the original 15 inch rims.

Here in the Phillipines, you might want to compare it to the Amazon. Even the city has big pot holes and very uneven streets and my poor volvo is already scraping the underside.

I want to go as high as i can and wide as i can. I want to put 205/70/15 on it.
I do not mind if it scrapes or rubs when i hit a bump, as long as it does not puncture the tire. I also plan to find some shock extension things to make the car taller, maybe 50mm higher. it may sound stupid, but a high clearance 4x4 is what I want, a volvo 850 is all I got. I need to make this work.
thanks guys.

proud former owner of 122s, 1800s, 1800es. current owner of 1998 xc70, 2007 xc70, and 1995 850 sedan. Previous owner of 1972 DS21, 1962 DS19 (grills) 1968ds19 manual, and 1971 DS21

 

I don't think tire width really is what you need, but I agree you are better off with a taller sideway. From there you should also run higher air pressure to protect the rim - say on the order of 36-39 PSI. I think the 205/70-15s are a risky fit. The 195-60-15s are 24.1 inches in diameter, the 205/70-15s are 27 inches. - that's 1 1/2 inches less clearance. If you stay with a 195 or 205/65 you'd be only needing 1/2 inch.

Not sure what you mean by a shock extension but you can put a spacer between the strut mount and the fender mount. Interestingly, BMW did this back in the 70s when their bumper height was too low for US regulations. They stuck a 1/2 spacer between the strut and fender mount. I'm sure there's something on eBay or Amazon. As to the rears, you can go with spacers or even consider overload coils which will raise the ride height. Note that as you go up, you'll be altering suspension geometry so expect the handling to be worse. I'd be curious if the springs from an early vintage XC70 would fit into an 850...