(concurring):
Given the narrow scope of judicial review of the Secretary’s informal rule-making exercises,1 I do not perceive any legal vulnerability in his finding that labeling of retreaded tires with the information his standard mandates is essential to achievement of the objectives of the Act. Nor do I share my colleagues’ doubts that permanent labeling of that information on retreaded tires is vitally related to motor vehicle safety.2 Not even the tire industry disputes the technological feasibility of a process by which data can be permanently labeled on retreaded tires.
The problem, rather, is that the Secretary’s standard calls for permanent labeling on each retreaded tire of six individual characteristics of that tire. The methodology of permanent labeling on which the industry settled is insertion *42into the retread matrix of a slug that accomplishes the labeling. The number of combinations of characteristics is vast; a change of slugs becomes necessary each time a change of a single characteristic occurs, and the standard would currently intercept an estimated 20 million of the tires now retreaded annually.3 The administrative record echoes the many complaints that operational and economic havoc in the retreading industry will be the inevitable result.
In this milieu, I agree that the Secretary was summoned to focus on these realities. The Act directs the Secretary to consider, among other things, whether standards he proposes are “practicable,”4 and as the legislative history denotes, it does not suffice to view merely the “technological ability to achieve the goal of a particular standard.” 5 “[E]conomic factors”6 as well must be scrutinized, and these include “reasonableness of cost”7 and “feasibility.”8 And beyond the effect of the standard on the retreading industry was its obvious impact on a large segment of the motoring public.9
Our function respecting the standard under attack is limited. Nonetheless, “[t]he availability of informal rule-making procedures is not equatable with administrative fiat.”10 “There must be some assurance discernible that the administrative action was reasoned and based on a consideration of relevant factors.” 11 One may search the record before us for acceptable support for the Secretary’s conclusion that the test of practicality was met, but the search will be in vain. That, in my view, is the fatal flaw in the Secretary’s case.
. See Automotive Parts & Accessories Ass’n v. Boyd, 132 U.S.App.D.C. 200, 208, 407 F.2d 330, 338 (1968) ; H & H Tire Co. v. United States Dept. of Transportation, 471 F.2d 350, 352 (7th Cir. 1972).
. The Secretary has found that:
Tires . . . may be subject to many applications during their useful life. They are transferred from wheel to wheel and from vehicle to vehicle, and each time this takes place the information on the tire sidewall becomes important. Permanent labeling is therefore required if the information is to perform its function, as it can be readily assumed that affixed labels will last little longer than the first time the tire is mounted.
37 Fed .Reg. 5952 (1972). His decision is to be embraced not only where its elements are “amply supported by expert opinion in the record,” but also where they “seem[] evident to us as a matter of common experience.” Automotive Parts & Accessories v. Boyd, supra note 1, 132 U.S.App.D.C. at 211, 407 F.2d at 341.
. Approximately 30 million tires are retreaded in the United States each year. Of that number only about one-third permanently label the data which the Secretary’s regulation referable to new tires now requires.
. National Traffic and Motor Vehicle Safety Act of 1966, Pub.L. No. 89-563, tit. I, § 103(a), (f)(3), 80 Stat. 718 (1966), 15 U. S.O. § 1392(a), (f)(3) (1970).
. 112 Cong.Rec. 19648 (1966).
. Id.
. S.Rep.No. 1301, 89th Cong.2d Sess. 6 (1966).
. Id.
. See H & H Tire Co. v. United States Dept. of Transportation, supra note 1, 471 F.2d at 355. As the Secretary himself has stated “[t]here is a large segment of the motoring public that relies on retreaded tires for use on passenger cars.” 35 Fed. Reg. 4136 (1970).
. H & H Tire Co. v. United States Dept. of Transportation, supra note 1, 471 F.2d at 355.
. Id.