I've run 205/70/14 tires for years on my 240D 4 sp manual without any trouble with acceleration or hills. Do you have an automatic or manual? I might hestiate if I had an automatic. I need to replace this set soon (70K on them so far) and am going for the same size again. I get 31 to 32 mpg and I like the look better than the stock size.

JohnM 1983 240D 4sp manual 160K