High-performance summer rubber completely changes how your car corners and stops, but it does not come cheap. Between mounting, balancing, and faster treadwear, a solid set runs about $850 and usually needs replacing every few seasons. The sweet spot to buy is early spring, when tire brands roll out large rebates right before road trip and track season starts.
You want to separate getting the best price on the rubber from how you pay for it. Once you negotiate the purchase and stack seasonal promos, an interest-free promotional period lets you handle the out-of-pocket cost over time without draining your emergency fund.
Keep in mind that a 0% introductory window is a strict countdown, not free money. If you have any balance remaining after the 18 months, the card's standard ongoing APR applies to the rest, so stick to the monthly schedule until it is paid in full.