Advertisement: When your car's engine is running at its normal

55. Advertisement: When your car's engine is running at its normal operating temperature, any major brand of motor oil will protect it about as well as Tuff does. When the engine is cold, it is a different story: Tuff motor oil flows better at lower temperatures than its major competitors do. So, if you want your car's engine to have maximum protection, you should use Tuff.

Which of the following, if true, most strengthens the argument in the advertisement?

(A) Tuff motor oil provides above-average protection for engines that happen to overheat.

(B) Tuff motor oil is periodically supplied free of charge to automobile manufacturers to use in factory-new cars.

(C) Tuff motor oil's share of the engine oil market peaked three years ago.

(D) Tuff motor oil, like any motor oil, is thicker and flows less freely at cold temperatures than at hot temperatures.

(E) Tuff motor oil is manufactured at only one refinery and shipped from there to all markets.

IMPORTANT: The original poster reversed options A and C as they appear in the 2016 GMAT Official Guide.

Type: Strengthen
Boil It Down: Normal temp, Tuff =, at low, Tuff better, so better overall
Missing Information: There are no factors that could make Tuff less effective than maximum
Goal: Find the option that rules out factors that could jeopardize maximum protection claim
Analysis: The question appears to make a decent case that Tuff provides maximum protection if it’s as good as the others at normal temp, but better at lower temp. However, the fact that we’re asked to strengthen particular highlights the fact that there are some gaps, and we need to shore up those gaps. One big one is what happens at high temperatures? What if Tuff provides relatively poor protection at high temperatures? Then 'the maximum protection' claim would be hard to sustain.

A) Yes, here we go. This option shows that Tuff is also capable at high temperatures, and that’s exactly what was missing, therefore this option strengthens the argument by plugging that gap.

B) This option might make Tuff motor oil more enticing, but in no way does some sort of discount strengthen the argument that Tuff provides maximum protection. Gone.

C) If sales are down that wouldn’t strengthen the argument about the maximum engine protection. This option might attempt to even weaken by suggesting that something might be wrong with the oil if sales peaked three years ago, but of course sales and brand perception also has absolutely nothing to do with the argument about maximum engine protection, and even if it did, this option would weaken, so double trouble for C.

D) This option leaves us scratching our heads because it’s unclear how the free flow of oil relates to engine protection. We’d have to bring in outside knowledge and make unsupported assumptions about Engine oil behavior to even begin to guess at how option D relates to the argument.

E) This option seems to make the impression that Tuff motor oil might be scarce, but again this is an option that just doesn’t address the quality of engine protection whatsoever. The oil could be scarce or be readily available and still have limited engine protection.