What type of gas does a motorcycle (06 Ninja 250) take?

The difference between regular, super, and premium, from my understanding, is negligible, and mostly price.

BUT I could be wrong.

The higher the octane, the better. But not always worth the extra cost.

Mid grade octane is your best bet, and ethanol added fuels are common around here, but whether they are harmful to an engine is debatable. The cheapest grade burns too quickly, and premium is probably too pricey. I usually run mid grade for three or four fill ups, then run a tank of premium to clear up deposits. Running your engine full out a few times a month also helps keep the carbs clean, to blow out the cobwebs, as the gearheads call it.

Regular. Also, it’s not always the higher the octane the better. Engines are designed with specific compression ratio’s and a high octane placed into an engine designed for lower octanes will wear your engine more quickly and no enhanced performance will result. My GSX-R600 required regular so I would assume yours does as well. I woul pull the manual out though and take a look.