Car, jets and bikes card games
After a lot of searches, I finally figured out they are called "Top Trump Cards".

http://www.toptrumps.com (site appears to be down, from my side, though)

But it does appear that I have either recalled the rules incorrectly, or we made our own rules when we were kids (latter is the most probable).

I also found out where I could buy them in South Africa (where I live):

https://www.takealot.com/all?filter=Brand:Top+Trumps