Tires: will tire fit stock rim, rim width, true thanks

Question
I have an SUV with stock 16x8 rims   I would like to put some new tires on them.  I was thinking about 235-85-16's, but friend said the rims are to wide.  is that true?  Thanks

Answer
Alvin,

An LT235/85R16 has an acceptable rim width range of 6" to 7".  So, no, the tire will not fit on that rim.

But I suspect you are replacing P metric tires with LT metric tires and I recommend against that.  P metric tires are designed quite differently than LT metric tires and there are some circumstances where switching the two types just doesn't work.