My mustang has 435 advertised HP. The Kia Stinger, 367. The yet to be released Hyundai Veloster Type N, 275. Now my car's top speed is 155. The Stinger is 167. That is about the same top speed advertised for the Veloster. Does anyone see something wrong with this? I realize that not too many people would take their ride to the advertised limit, but I know that my stang is good for more than both of those wheezers. I am not angry, just a bit disappointed. One more data point: the 2012 Covette GrandSport that I once owned was lighter than my stang but had about the same rated HP with the active exhaust. It had a rated top speed around 185.

 

The Mustang is limited electronically by the factory. A tuner can remove that limit.

 

The reason why it's limited to 155 has to do with it now being a "global" car. All European cars are limited to 155 from the factory (God help you if you try to turn it off) which is why the S550 is limited to that speed. I don't know the legality here in the States of taking the limiter off so I have no opinion of how or if you can take it off and not have issues.

 

See several YOUTUBE videos of current Mustangs being driven flat out on the German Autobahn at 160+ mph. The cars are nice and stable. It is all about bragging rights. Without limiters, they may go 185+ since the new Bullitt goes 165+. Rear gearing also sets the top speed limits to some degree.

 

The S197 cars were limited right around 150, before it was a global car. There are many rumors as to why this speed was chosen, but no definitive answer. It really doesn't matter because a hand held tuner like the SCT 4 is all it takes to remove the speed limiter.

 

For the S197, what was the speed rating for the OEM tires for base GTs? Sometimes that is the rationalle for the limit. I used an SCT tuner to remove that limit on mine when it was natuarlly aspirated. No limit on the current tune for forced induction either.

 

I had mine up to 160 when I put my GT500 gauge cluster in and I didn't change anything. Weird.

 

I am not sure what the stock gt tires were. My car is equipped with the Brembo package that included higher performance summer only tires that were rated well above 150.

 

Mine is too. I doubt the brembo cars were tuned any differently though.

 

I know some tuners(companies) won't remove the top speed limiter unless you tell them you have an aftermarket driveshaft.