Quote from samjh :It's just poor wording. The two mean the same. "Has to have" is negated by "up to". "Has to have 6 cyls" = Must have only 6 cyls, no more and no less. "Has to have up to 6 cyls" = Has to have cylinders, up to six. The real technical regulations are probably better worded than the wiki article. With pedantics like that, you should be reading the real rules and exploiting the shoddy wordings for profit! Call up some teams!