Acrura will tell you premium. It is the same as the Acord so you could use REG. I do think the intake is diffrent and the Compressin Ratio is higher on the tsx so you may wnat to go with mid? This is just a stab in the back.
Honda Acura suggest Premium for the TSX and Regular for teh Accord. However, you can use whatever you want. You will not be able to gain full performance from the TSX. The TSX knock sensor will just adjust according to the Octane level.
That is why you should get a M6, it only requires Regular fuel to get more power than the TSX.
Nice Article in C&D This month basically saying that the TSX is really nothing special. It's a 3-Series wannabe that isn't on par with them and likely priced more than both the '6 and Accord v6 models, but only comes with a 2.4l i4 (200hp/166ft-lbs) that is slower than both.
I believe the actual quote was "an utter failure at being a BMW copy"
Its made my top 5 list cars to buy next. I just sold my Acura Integra 1995!!! Great car, excellent reliability... i guess thats why i am looking at another acura (if the price is right)... they just have great reliability..!
Reading the C&D article, it certainly sounds like this souped-up Euro-Accord doesn't offer much over the 6 besides a navigation system (I hate you, Mazda, for not making that available in the USA) and the hard-to-quantify "Hondaccura reliability."
Fewer horses, smaller interior (that back seat looks as small as the back seat in my old 89 Probe); and inferior handling, all for about $5 grand more than a Mazda 6.
Of course, it will outsell the 6. But nobody ever accused consumers of being smart.