AoA! My Cuore 07 has clocked 297,000 with original engine but showing signs of rings replacement as it reduces oil, shows engine blow by etc. It has lost it's acceleration and top speed by 10-20%. Being guided by pakwheels my opinion was the reason for low pick and top speed must be the weak engine i.e rings problem. But to my utter surprise, nearly every mechanic i visited told me the opposite. They all say that when the engine oil mixes with the fuel, it actually increases the pick and top speed of the vehicle and that there can be some other reasons for this low pick of my cuore. Will the experts please elaborate the possible reasons for low pick and low top speed of a car?