My dealer today tried to sell me on cleaning out carbon build up while my 2011 Prius (30k miles) was in for oil change - at $170 I thought this was a real "dealer scam" - my other prius also a 2011 has 65k miles and never has the dealer mentioned this nor does either car have any issues that I noticed - so my question is - this is just dealer money maker? Bernie King
I was thinking along the same lines as everyone else, until I came across this: Differences between Atkinson Cycle 2.0 (FFH) vs regular Ford 2.0 4cyl - Fuel Mileage - Ford Fusion Hybrid Forum Given that Atkinson-cycle puts some of the unignited air-fuel mixture back into the intake manifold... I do not know. I guess one can always run a snake cam down into the manifold and see.
Similar thing happened to me, except it was my Camry (non hybrid, Otto cycle) car, similar mileage to OP. Declined the throttle body cleaning, then they never brought it up during the next service visit. Go figure.