The CVs aren't....

They are reliable and easy to start but weak.

Nitro Rustler Racer was right to hit the R... the R engines are much stronger. Get the .18 cv-r [X if ya need it too]... I have one and it is great. It's stronger than the mega-expensive Sirio .18 out of the box and much easier to tune. You can't go wrong with the OS18, Tower still has them for just under ONE HUNDRED DOLLARS BUT THEY WON'T STAY THAT WAY... Definitely get one now...