dependability and reliability

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Senior Member
XY sees quality, dependability and reliability as a critical starting point for all vehicle manufacturers.

Isn't one of the underlined words redundant? Just a collocation for which other languages would use one word? Or am I missing a subtle difference between them?


  • fenixpollo

    American English
    As far as I can tell, they are synonyms and the use of both words would be redundant.

    However, thinking about the auto industry in particular, "reliability" might be used to refer to the mechanical strength or longevity of the car's parts. I think I have seen it used in engineering, automotive or aerospace industries.

    In that case, "dependability" might take on a more general meaning. If this were true, then the sentence would be talking about the quality of the car, the degree to which the consumer cound trust the car (dependability), and the strength and longevity of its parts (reliability)

    Just a supposition. Hope it helps.

    la grive solitaire

    Senior Member
    United States, English
    Hi Jana,

    What fenixpollo describes so well was my guess, too. The two are synonymous according to m-w; however, under "reliable" only, a second definition confirms the shade of difference:

    1 : suitable or fit to be relied on : DEPENDABLE
    2 : giving the same result on successive trials


    Lapsed Moderator
    English-Ireland (top end)
    OED agrees:

    Dependable: That may be depended on; trustworthy, reliable.

    Reliable: (1) That may be relied upon; in which reliance or confidence may be put; trustworthy, safe, sure. (2) Yielding concordant results when repeated.
    I really can't find anything to separate the two for most purposes. I would probably use dependable for people and reliable for things - but I could think differently tomorrow.



    Senior Member
    LGS and Fenix have given good explanations. Yes, it's redundant, but that may make it effective advertising copy.

    Dependable: It won't break down in the middle of the forest or desert.
    Reliable: the cooling system won't spring a leak four months after you buy the car.

    Dependable refers to the entire vehicle and its function, while reliable points at the components, and the lack of need for service.

    un saludo,


    India - English
    In statistics and engineering, reliability is the tendency of a system to be resistant to failure. It is mostly connected with the quality of individual
    parts used for making the system.

    Dependability is the trustworthiness of a system (as a whole) which allows reliance to be justifiably placed on the service it delivers. It is mostly connected with intelligence with which the overall system is designed.

    I am an engineer, and this is how these two terms are viewed in engineering.
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