Ok so just got a '06 4.2 and upon my travels from NYC to DC I found it's limited to 120mph, what is this ****piggery and how do I change it?!?

 

Be careful in some states if you exceed a certain speed and are caught you will have your car towed as you will be arrested.

I got caught a few weeks ago in CT with a Dragon radar gun at a speed well over that particular speed point, 85 mph, and the officer gave me a break and ticketed me for 85.

I broke all my own rules to get that ticket. I had a motorist in front of me with his rear fog lights on who kept speeding up and slowing down and I could not overtake on the inside so when he pulled over........

However to your point 120 mph seems quite low from what I have read in this forum and it certainly does not apply to my 2005 XJR.

 

If it's the NA then it may have a lower limit and been fitted with tyres (tires) rated to lower speeds. I expect the limit can be changed and new tyres fitted.