[Stoneage_Caddy]

Merl , i dont understand , why is it everyone is out to prove me wrong lately???...and why is it that it always someone with 10 or less posts thats never bothered to read the other threads on the subject?

here is the deal , bbob here on the forums is the guy that desgined the ht4100, 4.5 and 4.9 V8 engines found in front wheel drive cadillacs he also did the work on the northstar ....what he says is gospel for the 4.9 , he says to use premium ....the engine has no knock sensors and a couple other issues that require the use of premium fuel unless none is availbe then run enough of a low grade to get you where you can get premuim .....the ignition timing is set soft from the factory to allow the use of lower grade fuels in a pinch....an engine needs those knock sensors to dertimine the proper ammount of timing needed for optimum performace , the cadillac from the factory is set on a program ....it has no clue that the engine might be knocking (predetonation) or that anything less than premium is being used , thus it wont make the adjustments needed in that area , it can only guess whats going on thru the IAT sensor , engine load coolant temp and other sensors to determine current engine conditions

just because your grandmother does taxes for some guy that probably works ata dealer doesnt mean his word is the end all be all ...for god sake he lets you belive that knocking over a long perioid of time is a minor irritatation LOL.....