Just for comparison,lets say you bought a car that the manufacture claimed produced 300hp. You were somehow able to duplicate exactly the test method and conditions that the manufacture used (this is possible but not likely) and you ended up 25hp short, could you recover your loss?
I ask this because it seems you are on the path of saying “I bought this car because the manufacture made these engine output claims, now the manufacture must redude the engines output because it was not lasting long at the previous power levels”. (but it did make it out of warranty) Now you want compensated because you no longer have what you bought.There is some logic to the claim, but the manufacture can say “OK we leave your car alone,have a nice day”.