Simplify the following text for a Grade 5 native English-speaking person.
Original: The CA2010 is the same 2.4 litre V8 base of the CA2006 used by Williams , but has been re-tuned for the current 18,000 rpm limit required on all engines , down from its original 20,000 rpm implementation .
Simplified: The CA2010 is the same 2.4 litre V8 base of the CA2006 used by Williams . It has been re-tuned from 20,000 rpm to the current 18,000 rpm limit required on all engines .