The most it would have is 215 HP @ 4800 RPMs.
For a 1998 Lincoln Town Car : It depends on which state it is sold in and if it is single or dual exhaust Single exhaust ( 200 or 205 horsepower ) Dual exhaust ( 215 or 220 horsepower )
200 horsepower ( 215 horsepower with dual exhaust )
The advantages of having dual exhaust, if it is a true dual exhaust, include increased gas mileage, cooler engine temperature, and more engine horsepower. However, if it is not a true dual exhaust, it doesn't matter how many exhaust ports there are, there will be no advantage.
Dual exhaust and P71 210. Single exhaust 190
For a ( 2002 ) Mercury Grand Marquis : 220 horsepower ( 235 horsepower with dual exhaust )
According to the 1998 Lincoln Town Car Owner Guide : For the vehicles sold in California , New York , Massachusetts , Connecticut ( single exhaust 200 horsepower / dual exhaust 215 horsepower ) Outside of those four states mentioned above : ( single exhaust 205 horsepower / dual exhaust 220 horsepower )
According to the 1999 Ford Crown Victoria Owner Guide : With single exhaust ( 200 horsepower ) With dual exhaust ( 215 horsepower )
165
According to the 1998 Mercury Grand Marquis Owner Guide : Single exhaust ( 200 horsepower ) Dual exhaust ( 215 )
Dual exhaust systems increase capacity of the exhaust system and thus makes it easier for exhaust gasses to exit the combustion chamber. This can result in increased horsepower. However, dual exhaust is often used because the owner prefers a more "throaty" sound.
Not a significant difference all the dual exhaust does is cut back pressure ergo the louder sound
Maybe 10