are shown test results regarding the example the modification 2 and comparative examples 1 to 3 the construction of each tires used for the test such as the dimensional structure and the composition of the material for forming the side reinforcing rubber pad 2 are the same as those of the example unless otherwise specified further the comparative example 1 described below corresponds to a prior art tire shown in fig7 of ep 385192 a1 durability mileage of a tire until rupture on a drum running at a speed of 80 km hr under a pneumatic pressure of 0 is shown by an index when the comparative example 1 was assumed to have an index of 100 ride quality a result of a sensual test by a driver is shown by an index when the evaluation of a general tire at the rated pneumatic pressure is taken as a reference value with an index of 100 steering stability in the same manner with the evaluation of ride quality the ease of steering at the time of cornering was evaluated weight of tire the weight of tested tire relative to the weight as a reference value 100 of a tire of the type in which the fibrous layer extends along the inner liner comparative example 1 the durability test was performed under 85 of a rated load for the sensual test on ride quality a ff type passenger car of 1800 cc engine displacement was used as will be seen from the test results shown in the table 1 the run flat tire according to the embodiment of the present invention excels outstandingly in its run flat durability.