87 gas caused any damage on engine?

[antibiotics]

I test drived a 2001 continental with only 67k miles yesterday. The car seems be maintained well and runs smoothly. However, the engine just can't rev up quickly. Which looks odd to me since DOHC engine is prone rev up sprintly. Any insights on this?

Also owner said he only used 87 gas, will this cause any damage to engine?

[Towncar]

I can't imagine what would be damaged using 87. This car is designed for 91, and surely the 87 would degrade performance some if 91 gives optimum performance.

Yep, four valves per cylinder, it's a breather Exhaust and Cold Air Intake should be checked for free-flowing air.

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