It is always best to have the manufacturer's suggested grade of gas. The Type-S requires 91 octane (premium at most places)
premium
The 2006 Acura TSX has double overhead cam (DOHC).
The 2006 Acura TL has single overhead cam (SOHC).
The 2006 Acura MDX has single overhead cam (SOHC).
Use exactly what Acura recommends and nothing else. If it does not say use premium unleaded on the fuel door and in the owners manual then use regular. The use of premium is a total waste of money if that is not what Acura recommends.
The Acura RSX has a timing chain belt.
base - 160 hp premium - 160 hp Type-S - 200 hp
base - 160 hp premium - 160 hp type-S - 200 hp
You can save about $30,000 depending on the make and type of the 2006 Acura and the 2010 Acura model. In general, the MSRP of 2010 Acura's is about $42,000 to $53,000 depending on additions, while the 2006 is currently going for about $16000 to $26000 online (used, of course).
Stereo codes are unique to each stereo and you will have to get the serial number from the stereo and call an Acura dealer for the code.
regular unleaded. it states this in the owners manual
According to the link below these four cars require premium unleaded fuel.