Is this the latest sirio engine for 1/10 onroad ? How does it perform ?

IMHO, probably the best .12 engine on the market. It's a screamer with good fuel mileage..
Always run it with the Sirio pipe!

I wouldn't say its the best on the market, comes down more to personal preference but I can say it definitely screams hard on the top end - and when I say screams, I mean it absolutely hammers!

I used "standart" XXXV the whole year and don't have any problems. It has the same torque and top speed as Max Power. At last competitions I bought hand tuned version of XXXV and this engine has shown unbelievable power! It was faster then all Murnan's rb!!!
So now for me only Sirio!

is it factory tuned or what?

It was tuned by our local guys.

Sirio are a good engine, easy to tune, good power output, pretty cheap with a manifold and pipe combo.