Q5 - Motor oil serves to lubricate

[dan]

5. (E)
Question type: Weaken the Conclusion
The argument concludes that cheaper brand oils are the best buys. The reasoning is that the cheaper oils are just as effective as more expensive ones are at retarding wear on the relevant parts of the engine. However, retarding wear may not be the only function of a motor oil, and there may be other reasons that make one brand of oil better than another.

(E) addresses that flaw. It doesn’t make the argument completely false, but it does weaken it by exposing other avenues that perhaps ought to be explored.

(A) does not weaken the argument; it can be argued, in fact, that this would strengthen the argument.
(B) does not weaken or strengthen the connection between this evidence and the conclusion reached _ that is, the fact that other measures can be effective does not mean that this measure is not effective.
(C) does not weaken or strengthen the argument, but rather provides impartial background information.
(D) goes outside the scope of the argument.

[yusangmin]

hello

i got it down to B and E and E definetely seemed to close the gap closer.
basically what i pre-phrased is " but reducing engine wear might not be the only factor in what constitutes a worthy engine oil"
which is the authors main weak assumption right?
my question is. does B not touch up on this at ALL?

Although B doesnt come out explicitly saying "engine wear retardation isnt the only factor!" i felt like it was implicitly saying there were by saying there are other tests other than the ability to retard engine wear that can gauge quality of engine.

but either way the "other tests" just seemed icky so i chose E.

please let me know! thanks!

[farhadshekib]

hello

i got it down to B and E and E definetely seemed to close the gap closer.
basically what i pre-phrased is " but reducing engine wear might not be the only factor in what constitutes a worthy engine oil"
which is the authors main weak assumption right?
my question is. does B not touch up on this at ALL?

Although B doesnt come out explicitly saying "engine wear retardation isnt the only factor!" i felt like it was implicitly saying there were by saying there are other tests other than the ability to retard engine wear that can gauge quality of engine.

but either way the "other tests" just seemed icky so i chose E.

please let me know! thanks!

(B) does not weaken the argument (i.e. cheaper brands of oil are the best buys).

B suggests that there are other ways to gauge the quality of motor oil. This is completely irrelevant to our conclusion.

So what if there are other tests that can reliably gauge the quality of motor oil? For all we know, these tests might all suggest that cheaper brands of motor oil are the best quality, and therefore, strengthen the argument.

(E), however, suggests that motor oil serves other functions, besides the ability to retard engine wear, that are important to the running of an engine. If this is true, then the argument that cheaper brands of motor oil are the best option, because they can hinder engine wear, is weakened.

[bbirdwell]

I agree!

[samuelfbaron]

Isn't there a scope shift slightly here?

We move from talking about merely one factor in motor oil and what it does in engines, then we make a conclusion about the best motor oil?

Doesn't (E) highlight this flaw?

[noah]

Isn't there a scope shift slightly here?

We move from talking about merely one factor in motor oil and what it does in engines, then we make a conclusion about the best motor oil?

Doesn't (E) highlight this flaw?

I agree. I think you're basically saying the same thing that Dan said--just calling it a scope shift instead of whatever he said!

[billyye125]

Hello!

I still have a question: even though (E) says that there are other factors to be considered, but what if the other factors are actually the same across all brands of oils? So while it is possible to weaken the conclusion, it is still possible that it does not weaken it. Namely, it does not explicitly weaken.

I have encountered this issue with some other questions too: often choices that weaken the conclusion explicitly go against the direction of the conclusion, but sometimes the correct answers only "may weaken the conclusion". In this question, it may be that 90% of time other factors in consideration will make a difference, and 10% time not. We don't know which one it is, since it does not explicitly go against the direction of the conclusion. Isn't that "weakening" to loose?

Thank you!

[913361672]

I think (B) presumes that test of the ability to reduce engine wear can reliably gauge the quality of motor oil, but (D) draws question directly on the reliability of the test. That is why (B) is irrelevant.