Can you use regular gasline on Acura RDX?

no it requires premium because it's turbocharged. If you put regular in, the knock sensor will start to go off and your car will retard the timing and you'll have poor performance. That poor performance will get you less gas mileage and you'll lose the money you tried to save. No engine damage will result because your engine knows how to react but it'll only cost you more. You bought a RDX, clearly you have money. 20 cents more per gallon won't break your wallet

most of those luxery brands say you shouldnt use regular, and the car will run better w/better gas

the car manual and the gas tank door both say PREMIUM. Theres a reason car manufacturers put certain words in car manuals and on the cars themselves. So that the car will perform as it is supposed to, and not eat the engine, the tires, the tranny, etc..

The factory doesn't recommend it, and if you use it you'll lose power.

Turbo=Premium.