The steps in the picture below are too long lengthwise for me to be able to park full sized pickup truck very easily. The steps touch the corner of the truck when parked under there. I was wondering if I could cut the steps from left side(so open cut end would be against wall) to shorten the length across of steps without sacrificing its ability to support weight as it did before. I wouldn’t need to cut off much if I did, for it probably would be less than a foot cut off. Would angle grinder be best choice to do it with?
The maximum riser height is 8”. So, if the dimension from floor to floor is 16” or less, then you only need one tread. (See IRC R318.104.22.168)
Treads can be a minimum of 9”. (See IRC R322.214.171.124) However, I’d caution you on using a 9” tread with a 8” rise. Very awkward and I think dangerous.
Stair width is 36” minimum. However, a little known clause allows a 30” wide tread if there are at least two stairways leading to the same space and one of the stairways is at least 36” wide. (See IRC R311.7.1, Exception #2.). (I presume you have a stair from the front door to your overhead garage door that would be acceptable.)
BTW, the code discusses “walk lines”. I would make sure the edge of the steps align with the doorway opening...not the door trim, but the edge of the door opening. In your picture, it looks like you could reduce the step 2” or so from current length.