How much horsepower does a 1999 Pontiac Grand Prix GT have at the wheels when it has a 200 horsepower motor?

well im not ASE ceritfied but my brother is, and he's taught be a lot. When it comes to these types of questions it all depends on the condition of your car. Plus or Minus hp is a safe judgement. So if you keep regular maint. and your car is over all mid condition ( considering the car is 10 yrs old) then 195-205 would be a good idea of the hp. Or you can always go get your car Dyno'd . then you'll know for sure

I think the person who answered the last question misread that you had a GT and not a 240hp GTP. 195-205 would be a fair assesement if you had the GTP but with the 200hp GT your probably looking around 160whp. I think the GTP is actually around 190whp stock. But a general rule is to multiple your crank or engine hp by .17. This should give you a general range for hp loss but each driveline will be different. An AWD car will have a higher rate of loss.