It's not like restricting the speed limit to 180 will cause less accidents. Most accidents occur bellow 180km... How often do you see cars crashing around at 200.. The speed limit isn't the problem.
On a side note, it's foolish to compare 1.5 turbo to 1.8 because the turbo obviously has the edge.. But still, it's cool knowing the 1.8 is faster, technically.