Ramp both, when you ramp only one, you exceed the static WEIGHT RATING for the supported tire. TIP: If you have a rolling flat/ blowout, PLAN on replacing BOTH ASAP on that side. The rolling overload on the other tire does unseen INTERNAL DAMAGE, and it is easy to find MANY, MANY posts where owner blew the 2nd tire within 50-100-miles (due to this unseen internal damage)... often blaming MFR (unwarranted)