PTF97.S3.7 - Automobile manufacturers who began two decades ago...

chaplin___

First impression wise, this argument isn't great because the conclusion is so strongly worded ("no loss in safety"). We can strengthen this argument by showing that having two types of passenger vehicles on the road (one that's lighter and, hence, more fuel-efficient for driving local; another that's heavier and, hence, safer for driving on highways) does in fact save fuel without sacrificing safety.

Round 1 elimination:

A - can't quite see how this is relevant under timed, so saving this for later.

B - what kind of cars are we talking about? the lighter, more fuel-efficient ones or the heavier, safer (but less fuel-efficient) ones? and how much more are we talking about? if anything, B appears to weaken because it seems to show us one way that counteracts fuel-efficiency (if we were to assume that more cars driving on highways = less fuel-efficiency)

C - are "large" cars necessarily safer? we can't know for sure so we can't gauge its safety, which means we can't gauge the gains or losses in safety now versus twenty years ago

D - the argument is focused on two types of passenger vehicles only, not commercial vehicles.

E - can't quite make sense of this under timed either so saving this as well.

Round 2: down to A and E, both have a NA feel to them.

E gives us more info on our premise (manufacturers produced a type of passenger vehicle that's fuel-efficient), so E tells us what we already know. Of course some manufacturers had to have designed prototypes for fuel-efficient passenger vehicles first before actually producing them.

More importantly, E doesn't convince us that there's no loss in safety now that these two types of passenger vehicles are being driven.

A - a NA type strengthener.

Negating this: most households with family members who drive on highways don't own at least 2 passenger vehicles.

If that's the case, then it's unlikely that these people are driving heavier, safer cars on highways.

Why? Because it's reasonable to assume that they drive local too, and to achieve net savings in fuel use, these people should be driving lighter, more fuel-efficient cars. But that means they aren't driving in heavier, safer cars on highways, which strongly indicates that there is in fact a net loss in safety.

andre3000

@chaplin___ love the explanation. Not necessarily related to the question, and somewhat tangential, but curious by what you mean as a "NA type strengthener". Figured that's a cool way to think about it & I've never heard that before, have you identified the other sorts of "strengthener" types?

chaplin___

@andre3000 I can't remember where JY mentioned it but on some harder strengthening questions, the correct AC barely strengthens. This kind of AC feels like a NA because it's more so keeping the argument from falling apart (or tipping closer to the invalid end of the spectrum) as opposed to bolstering the argument. I meant "NA type strengthener" in the sense that stating outright an assumption that the author takes for granted does help strengthen the argument (just as explicitly stating the assumption then denying it hurts the argument on weakening questions). Hope that helps!

yang9999

@chaplin___ said:
@andre3000 I can't remember where JY mentioned it but on some harder strengthening questions, the correct AC barely strengthens. This kind of AC feels like a NA because it's more so keeping the argument from falling apart (or tipping closer to the invalid end of the spectrum) as opposed to bolstering the argument. I meant "NA type strengthener" in the sense that stating outright an assumption that the author takes for granted does help strengthen the argument (just as explicitly stating the assumption then denying it hurts the argument on weakening questions). Hope that helps!

yeah the Han Purple question in PT74 is very similar

andre3000

Awesome thanks @chaplin___ & @yang9999