Parents who have several young children close in age, multiples, or those who carpool with many young kids may not have the luxury of picking a full-sized convertible car seat, which we discuss elsewhere in this report. Space can also be a concern for taller drivers or passengers who need to preserve their leg room in front of convertible car seats.
A narrow seat that can fit three across, the Diono RadianRXT (Est. $290) has won a lot of fans for its ability to fit three across in a back seat. But the RadianRXT's true claim to fame is its high height and weight capacities: up to 44 inches and 45 pounds rear-facing, and 57 inches and 80 pounds forward-facing. The seat also converts to a booster that can keep kids safe up to 120 pounds. Children can be up to 44 inches tall rear-facing and 57 inches forward-facing.
The RadianRXT offers high-end convenience features like push-button LATCH connectors, but some reviewers complain about a challenging installation. The seat has a lower center of gravity and narrow path for anchoring the tethers or seat belt, which can make it difficult to route the straps and tighten them, particularly rear-facing. The seat lacks a no-rethread harness-height adjuster, but the harness tension is adjustable from the front. The cover is machine washable, but the harness has to be unthreaded to remove it.
The RadianRXT has received very good marks in independent crash testing when used as a harnessed seat. It has a steel-reinforced frame and side-impact protection that is bolstered with aluminum rather than plastic, which reduces seat bulk without sacrificing strength. The seat also offers side-wing head protection to keep children's heads from moving in a crash, and it can be tethered for greater stability both rear- and forward-facing. Like all convertible car seats, the RadianRXT has a five-point harness with a chest clip. Parents should note that the seat only gets fair crash-test marks in booster mode because of concerns over seat-belt placement.
Because of its narrow footprint, the RadianRXT is compact enough to fit three across in the backseat. However, it has a tall shell that can demand a lot of front-to-back room unless you use an angle adjuster, sold separately for about $10. The adjuster does an excellent job of providing more space, but children have to have full head control before parents can use it. The RXT has soft foam padding that keeps kids comfortable and absorbs impact, but it doesn't have armrests. It folds up for easier traveling, but at 23 pounds, it might not be worth it. Even if you don't need the RadianRXT for its space-saving abilities, note that its high height and weight limits make it a good pick for extended rear-facing and taller children in general.
Compact-car drivers who need a seat that's both narrow and short-shelled may be thrilled with the Combi Coccoro (Est. $200). At just under 12 pounds, it's also a car seat you won't break your back, unlike the Diono RadianRXT. The ample padding and smaller scale also make it a good pick for parents who want a convertible that cradles small babies. The seat accommodates children from 3 to 33 pounds rear-facing, with an infant positioner to help accommodate the smallest babies, and 20 to 40 pounds forward-facing. Children must be less than 40 inches tall.
The Coccoro has push-button LATCH connectors to secure and remove the tethers to the anchors more easily, as well as seat-belt lock-offs to maintain tension around the seat. Its smaller size and lighter frame make it easier to install than bulkier seats, reviewers say, but the curved shell can make getting a tight rear-facing installation tricky when you're not using LATCH. The harness tension is easy to adjust, but the four-position harness height adjusts from the rear. The Coccoro does not have an adjustable crotch strap. The seat cushion is machine washable, which is good since some owners complain that the fabric stains easily.
The Coccoro gets high crash-test ratings in independent tests. In the past, users complained that the seat could flip toward the backseat in the rear-facing position. Combi has corrected this problem by updating newer models of the Coccoro with improved seat-belt lock-offs and a rear-facing tether that stabilizes the car seat and reduces movement in a crash. The Coccoro also features side-impact protection and energy-absorbing foam. It has a five-point harness with a chest clip, standard on convertible car seats.
Most parents can fit three Coccoros across in the backseat, and the short shell means it also won't hog room from front to back. Parents and expert reviewers both praise the comfortable fit that the Coccoro offers for very small infants and babies. However, the Coccoro's low weight rating of 40 pounds forward-facing and its 40-inch height limit may mean you'll have to buy a bigger car seat before your child is booster-ready -- probably not the case with the RadianRXT.
If you need a small convertible seat and are on an equally small budget, the Safety 1st Guide 65 (Est. $85) is a good value that can keep children safe a bit longer than some other lower-priced seats, reviewers say. The seat accommodates children rear-facing from 5 to 40 pounds and forward-facing from 22 to 65 pounds. The rear-facing height limit is 40 inches, and the forward-facing height limit is 52 inches, so it has a longer lifespan than the Combi Coccoro, but not as long as the Diono RadianRXT.
Experts with CarSeatsForTheLittles.org caution that the Guide 65 is not the easiest seat to install. For example, seat-belt installations can be tricky because of a small, finger-scraping belt path. Rolled towels or pool noodles may be necessary to maintain a proper recline. You'll also need to rethread straps from the back when adjusting the harness height -- typical for budget seats. The seat cover is hand-wash only.
Just like seats three times its price, the Guide 65 gets very good marks in independent crash testing. It does not have a lot of safety extras like those pricier seats, however. You'll get side impact protection, a five-point harness, LATCH connectors, and a top tether -- all standard for convertible car seats. The seat does not allow for rear-facing tethering.
Parents with several small children can fit three Guide 65s in the back seat. Experts also say the seat's short shell won't take up too much room front to back, making it a good pick for compact cars. At 14 pounds, it's also relatively light for a convertible seat, though still heavier than the Coccoro. Most parents are happy with the padding for the price, saying their children seem comfortable, but some caution that their kids' heads slump during naps. Despite the seat's 5-pound weight minimum, experts say smaller babies will not fit properly -- you won't be able to use the Guide 65 in place of an infant seat. However, it has higher height and weight limits than other budget seats, so your child won't outgrow it as soon.
If you want a couple more compact convertible options and have a healthy budget, two more worthy contenders are the Clek Fllo (Est. $380) and Maxi-Cosi Pria 70 (Est. $250). At 17 inches across, the Fllo is another narrow seat that can fit three across, and it has cutting-edge safety features including an anti-rebound bar. It's also a good pick for extended rear-facing. The Pria 70 is a front-to-back space saver that would work well in compact cars. It fits babies as small as 4 pounds, and it's thickly padded for comfort. Experts say both seats are relatively easy to install.