Thicker pasta means chewier, longer cook time

Yes. Number 9 and 11 are standard spaghetti thicknesses, and the difference matters.

Number 9 is thinner (roughly 1.5mm). It cooks faster—usually 8–9 minutes for al dente. The mouthfeel is delicate, almost silkier. It clings to light sauces (aglio e olio, tomato basil) well because there’s less starch mass to overwhelm the flavor. But it can get mushy fast. Don’t walk away.

Number 11 is thicker (about 1.8mm). Takes 10–12 minutes. The bite is more substantial—chewier, more “tooth.” It stands up to heavy sauces (bolognese, carbonara, anything chunky) without turning into paste. You get more pasta per bite, which some people prefer.

The trick isn’t brand loyalty—it’s matching thickness to the sauce. Thin pasta + thin sauce = balanced. Thick pasta + thick sauce = hearty. Swap them and you either get overwhelmed noodles or sauce that slides off.

Pick based on what you’re putting on top, not what’s on the box.