Hi 3030; yes, you can use R4 tires. Keep the following in mind concerning mowing: 1) using 4wd tends to chew up the grass when turning; so keep it in 2wd. 2) If ALL your work will be mowing, or if the lawn is beautiful and perfectly manicured, turf tires would be worth the investment. Otherwise, R4's are fine because you need the traction on your other work. 3) for mowing, weight is not the issue; so don't have liquid in the tires if possible.