For a spare tire, liposuction or coolsculpting are both possibilities. In terms of pure cosmetic result, liposuction is better, but it is also more expensive and requires more downtime. Which treatment is better for you depends on your overall health, physical exam, goals, whether you are able to have downtime, and your pocketbook.
Overall health: Liposuction candidates are people in relatively good health without heart problems, kidney problems, bleeding problems, or a history of anesthesia-related problems. Almost anyone can have coolsculpting, since it is noninvasive.
Physical exam: Liposuction can reduce soft fat as well as firmer, fibrous fat. Coolsculpting works best for soft, pinchable fat. Neither procedure addresses excess skin or visceral fat (fat around the internal organs). If excess skin is an issue, a tummy tuck in combination with liposuction should be considered.
Your goals: Liposuction can give a dramatic and "customized" result and can address the abdomen and flanks in one session. Coolsculpting can only reduce a limited area with each session so if your spare tire extends from your abdomen to your love handles, you will require multiple coolsculpting sessions to cover all these locations. These sessions can be done back-to-back.
Downtime: There is almost no downtime with coolsculpting. Most patients have minimal discomfort and can resume your normal activities immediately. With liposuction, you will have several days of downtime, bruising, and you will need to wear compression garments for at least a couple of weeks.
Pocketbook: Liposuction costs depends on the surgeon's fees, anesthesia fees, facility fees. The price of coolsculpting depends on the number of coolsculpting sessions that you would need to get your desired result.