Generally speaking Mexicans are very capable drivers and they are fast drivers. Here in the US I'm probably at a 98 percentile for speeding, but in Mexico even on a motorcycle I drop to 85 (out of 100 cars I'll pass 85 and 15 will pass me) even though I'm not consciously trying to go slower.
Many Nationals will drive 60mph in a 60kph zone and most speed limits are set so low so as to make all drivers subject to a speeding ticket.
I've noticed that Nationals will usually return to the right lane after making a pass (on multi-lane divided highways)- something that I wish Americans might do more.
It's pretty amazing - in the 17 years I've been driving in Mexico the number of vehicles on the road has exploded; that should mean there are a lot of inexperienced drivers - but for the most part they all do pretty well behind the wheel.
In the cities or in the mountains - Mexicans can drive.