whom Mr. Justice Whittaker, and Mr. Justice Stewart join, dissenting in Nos. 141 and 143, and concurring in the judgment in No. 283.*
This is one of those situations where what may be thought to be an appealing practical position on the part of the Government has obscured the weaknesses of its legal position, at least in Nos. 141 and 143.
The position which the Commissioner takes in these cases with respect to the basic issue of “useful life” is that contained in the regulations promulgated by him in 1956 under the Internal Revenue Code of 1954, which define the useful life of a depreciable asset as the
“period over which the asset may reasonably be expected to be useful to the taxpayer in his trade or business . ...”1
In No. 283 the Commissioner seeks to apply this regulatory definition to the returns of the taxpayer with respect to the taxable years ended March 31,1954,1955, and 1956. *108In Nos. 141 and 143 he seeks in effect to apply the same definition to the taxable years 1950 and 1951, both of which were of course long before the enactment of the 1954 Code. See 264 F. 2d, at 506.
I agree that these regulations represent a reasonable method for calculating depreciation within the meaning of the 1954 Code, and that they are valid as applied prospectively. But since I believe that as to “useful life” they are wholly inconsistent with the position uniformly taken by the Commissioner in the past, I do not think they can be applied retrospectively in all instances. While I consider that the regulations may be so applied in No. 283, in my opinion that is not so in Nos. 141 and 143.
I.
It is first important to understand the precise nature of the issues before the Court. Both the method of depreciation contended for by the taxpayers and that urged by the Government purport to allocate an appropriate portion of an asset’s total cost to each o.f the years during which the taxpayerholds it. Both methods define the total cost to be so allocated as the original cost of the asset less its salvage value at the end of its useful life. And under both methods, the total cost to be allocated is divided by the number of years in the useful life and the resulting figure is deducted from the taxpayer’s income each year he holds the asset. As the Court correctly notes, the practical difference in the end results of the two methods involves the extent to which a taxpayer may be able to obtain capital-gains treatment for assets sold at or before the end of their useful life for amounts realized in excess of their remaining undepreciated cost.
The difference between the two methods from a theoretical standpoint is simply this: The taxpayers define useful life as the estimated physical life of the *109asset, while the Government defines the term as the period during which the taxpayer anticipates actually retaining the asset in his business. Thus, under the taxpayers’ system, the total cost to be allocated is original cost less the salvage or junk value of the asset at the end of its physical life. This figure is divided by the number of years of estimated physical life, and the quotient is subtracted from income each year the taxpayer holds the asset. Under the Government’s method, the total cost to be allocated is original cost less the “salvage” value at the end of the asset’s actual use in the business, that is, less the price anticipated on its resale at that time, even though the asset may not be in fact physically exhausted. This figure is divided by the number of years in the holding period, and the quotient is subtracted from income each year the taxpayer holds the asset.
If an asset is held until it is physically exhausted, both methods produce exactly the same result. Similarly, both methods can result in inaccuracies if predictions of useful life and salvage value turn out to be wrong. The Government, however, contends that where it can be predicted with reasonable certainty that an asset will be disposed of before the end of its physical life, its method of depreciation is more likely to reflect the true cost of the asset to the particular business. This is said to be so because the true cost to the business, in the end, is the asset’s original cost less the amount recovered on its resale, and the Government’s method starts from an estimate of that amount, which is then allocated among the years involved. The taxpayers’ method on the other hand, starts from an estimate of the end cost of the asset in the general business world, and will accurately reflect such cost to the taxpayer’s business only if the decline in market value at the time of resale can be expected to correspond roughly to the portion of the asset’s general business end *110cost which has been theretofore depreciated. In many cases that may be true, but in the present cases, there is in fact a great disparity between actual decline in market value at the time of resale and the portion of cost theretofore depreciated under taxpayers’ method.
It need not be decided whether, as an abstract matter, one method or the other is deemed preferable in accounting practice. Apparently there is a split of authority on that very question.2 It is sufficient to note that in most instances, either method seems to give satisfactory results. Assuming that because of the unusual case, such as we have here, the Government’s method on the whole may more accurately reflect the cost to a particular taxpayer’s business, the question for me is whether the Commissioner has nevertheless established a practice to the contrary upon which taxpayers were entitled to rely until changed by him. I turn now to the examination of that question.
h-i HH
The Court relies on the wording of certain revenue statutes and regulations to show that the period during which depreciable assets are employed in the taxpayer’s business, as opposed to the period of their physical life, has always been regarded as useful life for purposes of depreciation. Concededly, the term useful life did not appear in the statute until the Internal Revenue Code of 1954, and though it had appeared in the regulations as early as 1919, Treas. Reg. 45, Art. 161, was never defined therein until 1956, ante, p. 107, when the Commissioner took the position he now asserts. The Court seizes on language which was not directed to the present problem and which could equally be read to support the *111Government’s or the taxpayers’ contention. The situation before 1956 was as follows:
The Act of Oct. 3, 1913, permitted a reasonable allowance for “wear and tear of property arising out of its use or employment in the business.” 3 It is certainly true, as the Court says, that this means that “the wear and tear to the property must arise from its use in the business of the taxpayer.” But it does not follow at all that the formula for calculating that wear and tear must be based on a useful life equal to the period the asset is held in the business. For, as noted above, a formula based on the physical life of the asset also results in an estimate of the portion of the asset’s total cost attributable to its use in the business, and may in some circumstances yield the same tax consequences as a “holding-period” formula.
Treasury Regulations 45, Art. 161, promulgated in 1919 and continued in substantially the same form until 1942, provided that the taxpayer should set aside each year an amount such that “the aggregate of such amounts for the useful life of the property in the business will suffice, with the salvage value, at the end of such useful life to provide in place of the property its cost . . . .” In 1942, the statute was amended to permit depreciation, not only, as before, on property used in the trade or business, but also on property held for the production of income. Accordingly, the regulation was revised to delete the words “property in the business” and substitute therefor “the depreciable property.” Reg. Ill, § 29.23 (Z) — 1. The Court says that the deleted term could not have been meant to define the type of property subject to the depreciation allowance, since that function was already performed by another section of the regulation. That may be true, but it does not show that the language was meant to define the period of useful life.- If it had been so meant, the Commissioner *112would hardly have simply substituted “useful life of the depreciable property” for “useful life of the property in the business,” but would have inserted appropriate language, such as “useful life of the property while used in the business or held for the production of income.” It is quite evident that the question of a holding period different from the physical life of the property was never adverted to, and that the term “property in the business,” while not an affirmative definition of the type of property subject to depreciation, simply referred to that definition in connection with useful life because it was apparently assumed that assets were generally held in a taxpayer’s business until worn out.
In light of the above, the Government’s reliance on cases such as United States v. Ludey, 274 U. S. 295, 300-301, and Detroit Edison Co. v. Commissioner, 319 U. S. 98, 101, is wide of the mark. The language relied upon in Ludey is virtually identical to that contained in the pre-1942 regulations, and that in Detroit Edison merely says that the purpose of depreciation is to recover, by the time of an asset’s retirement, the original investment therein. As noted above, depreciation based on either definition of useful life is dedicated to that end. The Government’s reliance on Bulletin “F” is also misplaced. The Court refers to a statement on page 2 of the Bulletin which merely lifts from the regulation the phrase “useful life of the property in the business.” The Court also relies on a statement appearing on page 7, defining salvage as. “the amount realizable from the sale . . . when property has become no longer useful in the taxpayer’s business and is demolished, dismantled, or retired from service.” (Emphasis added.) The italicized language again reveals the assumption that assets were generally intended for use in the business until their physical exhaustion. The present question was never adverted to.
*113I believe, therefore, that the statute and regulations are wholly inconclusive, and' that the Commissioner’s position can be gleaned only from the stand he has taken in litigated cases. I turn now to those cases. Contrary to the picture of uncertainty which the Court draws from them, I believe they leave little room for doubt but that the Commissioner’s pre-1956 position on “useful life” was flatly opposed to that which he now takes.
III.
In examining the cases, it must be borne in mind that even the Commissioner does not contend that a taxpayer who happens to dispose of some asset before its physical exhaustion must depreciate it on a, useful life equal to the time it was actually held. It is only when the asset “may reasonably be expected” to be disposed of prior to the end of its physical life that the taxpayer must base depreciation on the shorter period. Reg. § 1.167 (a)-l (b). Therefore, the only cases relevant in this regard are those in which the taxpayer’s past experience indicated that assets would be disposed of prior to becoming junk, thus presenting the issue whether the shorter or longer period should control for purposes of depreciation.4
In four such cases, involving tax years prior to 1942, the taxpayer had a practice of disposing of assets substantially prior to their physical exhaustion. In Merkle Broom Co., 3 B. T. A. 1084, the taxpayer customarily disposed of its automobiles after two years. It attempted to depreciate them over a three-year useful life; the Com*114missioner asserted a five-year useful life; and the court allowed four years.
In Kurtz, 8 B. T. A. 679, the taxpayers customarily sold their automobiles after two or three years at substantial values. They depreciated on a four-year useful life; the Commissioner asserted a five-year life; and the court agreed.
In Sanford Cotton Mills, 14 B. T. A. 1210, the taxpayer customarily disposed of its motor trucks after two and one-half years. It claimed a three-year useful life; the Commissioner asserted a five-year useful life; and the court found that four years was reasonable.
In General Securities Co., 1942 P-H BTA-TC Mem. Dec. ¶ 42,219, the taxpayer sold its automobiles after one or two years. The court held that a reasonable useful life was three years.
It is apparent from these cases that both the Commissioner and the courts were thinking solely in terms of the physical life of the asset, despite the fact that the taxpayer customarily held the assets for a substantially shorter period. In at least some of the cases, it would have made a very real difference had depreciation been calculated on the basis that the useful life of the asset meant its holding period. For example, in the Sanford case, taxpayer’s trucks were sold after two and one-half years at less than one-seventh of their original cost. Given the five-year useful life proposed by the Commissioner, taxpayer would have had, at the time of resale, an undepreciated basis equal to half the original cost, while the proceeds of resale would have brought it only one-seventh of original cost, thus giving rise to a loss of the difference. If the Government’s present position had been applied, the difference between original cost and resale value would have been depreciated over two and one-half years, giving rise to no gain or loss at the end of that time. Similarly, in the General Securities case, given a three-year useful life, the *115taxpayer’s automobiles, when traded in after one year, had an undepreciated basis of two-thirds of original cost, yet their resale brought only one-half to one-third of their original cost, again resulting in a substantial loss which would have been avoided under the Government’s present method.
It is true that the only tax distortion present in these cases was a shift of ordinary deductions from the years in which the property was used in the business to the final year of its disposition. It is also true that had the situation been reversed, so that depreciation on a physical-life basis outran decline in market value, the resulting gain in the year of disposition would have been ordinary income, since capital-gains treatment for disposition of property used in the trade or business was not accorded by Congress until 1942.5 However, it is significant that the Commissioner’s adherence to a physical-life method did result in a distortion of income by shifting deductions among various tax years, which often entails serious revenue consequences, and that by 1942 physical life seems to have been uniformly accepted as the proper definition of useful life.
In light of these circumstances, four cases involving tax years subsequent to 1942 acquire special significance. In Pilot Freight Carriers, Inc., 15 CCH T. C. Mem. 1027, the taxpayer disposed of its tractors after an average of 38 months and its trailers after an average of 32.6 months. It claimed depreciation on a four-year useful life with 10% or less salvage value. The Commissioner asserted useful lives of five and six years for the tractors and trailers, respectively, and the court found that four and five years, respectively, was reasonable. It is to be noted that upon resale, taxpayer received, because of wartime inflation, amounts substantially in excess of undepreciated *116cost, resulting in large capital gains. Yet the Commissioner, in attempting to correct this disparity, asserted only that useful life should be increased to reflect more accurately the physical exhaustion of the assets, not that it should be equated with the holding period.
In Lynch-Davidson Motors, Inc., v. Tomlinson, 58-2 U. S. T. C. ¶ 9738, an automobile dealer disposed of company cars each year when new models were brought out, yet depreciated on a three-year useful life with salvage value of $50. The Commissioner did not dispute this method of depreciation and the court held it to be proper. In the companion case of Davidson v. Tomlinson, 58-2 U. S. T. C. ¶ 9739, taxpayers were in the automobile rental business, and kept their automobiles only one year. They also were permitted to depreciate on a useful life of three years with $50 salvage value. The striking similarity between the facts of these two cases and those of the present ones need not be elaborated.
Finally, as late as 1959, in Hillard, 31 T. C. 961, the Commissioner took the position that the taxpayer, who operated a car rental business, and who disposed of his cars after one year, should depreciate them on the basis of a four-year useful life rather than the three years contended for by taxpayer.
Thus in all these cases, as in the cases before us, the problem of offsetting depreciation deductions by capital gains existed; nevertheless the Commissioner consistently adhered to the position, adopted long prior to 1942, that physical life controlled.
The Court, however, seems to believe that the effect of these cases is vitiated by several cases dealing with “salvage” value. In three of such cases,6 the assets were *117apparently held by the taxpayer until at or near the end oí their physical lives, and the only issue was whether the taxpayer had erroneously calculated the salvage value at the end of that time. Thus they are of no significance for present purposes.
The Court’s view fares no better under any other of these cases. In Bolta Co., 4 CCH T. C. Mem. 1067, involving a 1941 tax year, the taxpayer disposed of several machines after they had ceased to be useful in its business but while they were still useful in other businesses. It projected an average holding period of five years and assumed no salvage value. The Commissioner acquiesced in the five-year useful life but contended that the taxpayer could reasonably have anticipated a salvage value equal to 25% of original cost. The court agreed.
In Koelling v. United States, 57-1 U. S. T. C. ¶ 9453, taxpayers disposed of cattle after they were no longer useful for breeding, and depreciated them on a useful life equal to that period, making no allowance for salvage value. The Commissioner found that it was unreasonable thus to deduct the entire cost of the animals over their breeding life, and required the taxpayers to deduct as salvage value their predicted resale price.
In Cohn v. United States, 259 F. 2d 371, taxpayers had established flying schools during 1941 and 1942 under contract with the Army Air Corps. The arrangement was expected to last only until the end of 1944, and the useful fife of property used in the business was calculated on that basis, with no allowance for salvage value. The Commissioner asserted various longer useful lives for the property, varying from five to ten years. The court permitted the taxpayers to use the shorter useful life, but required them to deduct the reasonable salvage value of the equipment which would be realized at the end of that period. The Government did not appeal from the useful-*118life ruling and the only dispute was over the correct amount of salvage value.
Thus in two of the relevant salvage-value cases, Bolta and Koelling, the taxpayer himself proposed a useful life equivalent' to holding period but employed a hybrid version by failing to adopt the corresponding concept of salvage value. The Commissioner merely took the position that if the holding-period method was to be used, it must be used consistently by deducting the appropriate salvage value. In the third, Cohn, the Commissioner actually rejected the taxpayers’ attempt to employ the holding period and merely acquiesced when the court permitted the taxpayers to do so, provided the corresponding salvage value was deducted. However, in no case, until the present ones, does it appear that the Commissioner has ever sought to require the taxpayer to use the holding-period method where the taxpayer has attempted to use physical life. And I do not understand the Government to controvert this. To the contrary, the Commissioner has not infrequently required the taxpayer to depreciate on the basis of physical life where the taxpayer had attempted to employ a shorter period, even in instances where significant capital-gains consequences turned on the difference. Indeed, as the Lynch-Davidson, Davidson, and Hillard cases, supra, indicate, the Commissioner, until quite recently, has adhered to the physical-life concept in automobile cases virtually indistinguishable from the present ones. In the past the Commissioner, unsuccessfully, has merely sought to curb the capital-gains possibilities in such instances by contending that the automobiles involved were not depreciable assets subject to capital-gains treatment under § 117 (j) of the Internal Revenue Code of 1939. Having conceded that the property involved in the present cases is subject to the depreciation deduction, I do not think the Commissioner should now be permitted to defeat his own position as regards the *119meaning of “useful life” — a position consistently maintained by him over a period of 33 years from 1926 to 1959 in every litigated case to which our attention has been called — by requiring these taxpayers, in respect of taxable years not subject to the provisions of the 1954 Code, to adopt a holding-period formula for useful life in depreciating the assets in question. Cf. Helvering v. R. J. Reynolds Tobacco Co., 306 U. S. 110, and Helvering v. Griffiths, 318 U. S. 371. In the application of this salutary principle it should make no difference that the Commissioner’s earlier different practice was not embodied in a formal regulation. Cf. Helvering v. Reynolds, 313 U. S. 428, 432; Higgins v. Commissioner, 312 U. S. 212, 216.
Accordingly, I would reverse in No. 141 and affirm in No. 143.
IV.
The situation presented in No. 283 is, however-, different. The taxable years in question there are those terminating on March 31, 1954, 1955, and 1956, respectively. All the taxable years thus ended before the promulgation of the new depreciation regulations on June 11, 1956.7 The Government concedes that Congress did not change the concept of useful life when it enacted the 1954 Code. Therefore, the question here is whether the Commissioner can, by a formal regulation, change his position retroactive only to the effective date of the statute under which it is promulgated.
Petitioner, relying on Helvering v. R. J. Reynolds Tobacco Co. and Helvering v. Griffiths, supra, asserts that where a regulation interpreting a statute has been in force for some time and has survived the re-enactment of the statute, the Commissioner cannot retroactively change *120that interpretation by a new regulation. However, here the Commissioner’s earlier adherence to the physical-life concept of useful life was expressed not in the regulations — which did not refer to the problem — but in his own administrative practice. Therefore, the present case is more like Helvering v. Reynolds, 313 U. S. 428, wherein this Court permitted the Commissioner to apply a regulation retroactive to the effective date of the statute under which it was promulgated, where his previous contrary position had been expressed only by informal administrative practice, even though the statute had been re-enacted in the interim. Application of this principle in the present case is the more called for, since Congress, in the 1954 Code, has for the first time used the term “useful life” and has made the availability of certain new accelerated methods of depreciation — among them the so-called “declining balance method,” used by the taxpayer here — dependent upon its definition. It is appropriate therefore to permit the Treasury maximum discretion in integrating the concept of useful life into the new provisions and in doing so from the effective date of the statute forward.
Since the statute permits use of the declining-balance method only as to property with a useful life of three years or more, it follows that the Commissioner properly disallowed use of the declining-balance method as to Hertz’ automobiles, whose useful life under the new regulation was less than three years. As to its trucks, admittedly held for more than three years, the only remaining question is whether Hertz should be allowed to depreciate them below what the Commissioner considers to be a reasonable salvage value. Given the fact that the Commissioner’s definition of salvage value as resale price on disposition of the asset at the end of its holding period is validly applicable to Hertz, it becomes important that the declining-balance method not be construed to defeat *121that concept. Were there no “salvage stop” in connection with declining-balance depreciation, it is clear that taxpayers who held assets for relatively short periods of time might be able to depreciate far below anticipated resale price, since the declining-balance rate is applied against the entire cost of the asset undiminished by salvage. Since the legislative history of the statute in this regard is ambiguous at best, and since there is no prior statute or administrative interpretation to bedloud the issue, the Commissioner’s construction should be allowed to stand. Accordingly, I concur in the Court’s judgment affirming No. 283.
Mr. Justice Douglasjoins Parts I, II, and III of this opinion. He would, however, reverse in No. 283 — Hertz Corp. v. United States, on the ground that the change in administrative practice involved here should not be retroactively applied under the circumstances of this case. Cf. United States v. Leslie Salt Co., 350 U. S. 383, 396.
[This opinion applies also to No. 283, Hertz Corporation v. United States, post, p. 122.]
Treasury Regulations on Depreciation, §1.167 (a)-1 (b), T. D. 6182, 1956-1 Cum. Bull. 98. June 11. 1956.
At the trials below, taxpayers’ expert 'witnesses testified that depreciation based on physical life was the commonly accepted accounting standard. Several textbooks, cited by the Court, ante, p. 106, take the contrary view.
38 Stat. 114, 167.
Three cases cited by the Court, West Virginia & Pennsylvania Coal & Coke Co., 1 B. T. A. 790; James, 2 B. T. A. 1071; and Whitman-Douglas Co., 8 B. T. A. 694, involved isolated dispositions of assets prior to their physical exhaustion, and there was no evidence indicating a consistent practice by the taxpayer in this regard.
Revenue Act of 1942, § 151, 56 Stat. 846.
Wier Long Leaf Lumber Co., 9 T. C. 990; W. H. Norris Lumber Co., 7 CCH T. C. Mem. 728; Davidson, 12 CCH T. C. Mem. 1080. In the Wier case, it is not clear whether some of the assets might have been useful for some additional period in other businesses.
T. D. 6182, 1956-1 Cum. Bull. 98. Prior to that time the regulations under the 1939-Code were continued in force. T. D. 6091, 1954-2 Cum. Bull. 47.