Chicco OneFit Max

The Chicco OneFit Max is an all-in-one car seat for children 5 to 100 lb. that transitions from harnessed mode to booster mode as your child grows. In CR’s tests, the Chicco OneFit Max provides excellent crash protection and easy, secure installation in both rear-facing and forward-facing positions with either LATCH or seat belt installations. However, the manufacturer recommends using the seatbelt and tether strap for installation when forward-facing, rather than the LATCH system. CR child passenger safety experts recommend rear-facing until a minimum of age 2, although the OneFit Max allows forward-facing at age 1 year.

The OneFit Max’s longer seat shell provides slightly more legroom for your child when rear-facing than the OneFit LX, though the rear-facing limit is still 40 lb., the same as the LX model. Given the longer seat shell on the Max, we found that it takes up more room in the back seat, and the booster mode may be a better fit for older children whose legs may bend over the front edge more naturally than younger kids with short legs. (Not being able to bend their knees over the edge of the seat commonly results in kids slouching in boosters and a poor lap belt fit.) 

CR’s testers note that the seat is bulky and fairly heavy at 27 pounds, making it harder to move the seat between cars. The OneFit Max may also not be a great fit for cars with smaller backseats or short seat cushions, as the seat base overhang may exceed the car seat’s max allowance of three inches. 

This seat may be a good choice for: 

• Families who want to purchase an all-in-one car seat (as opposed to using an infant seat for the first year and then switching to a convertible seat) 
• Families who don’t need to move their car seat between multiple cars
• Anyone who needs a simple and straightforward installation, thanks to the push-on LATCH connectors and seat belt lockoff 
• Those who want a roomier rear-facing experience for their child
   

Ease of use: Overall, the Chicco OneFit Max all-in-one car seat was very easy to use, with a simple and streamlined installation process, easily adjustable harness and headrest, magnetic buckle, and push-on LATCH connectors.

Fit-to-vehicle LATCH: Installation was simple and secure, and the fit is very good, though the Chicco OneFit Max’s larger size and footprint may limit use of the vehicle's front seats.

Fit-to-vehicle belt: The Chicco OneFit Max offers an excellent and secure fit when installing with the seat belt in forward-facing position, though when used rear-facing, we found the recline position may be too reclined for optimal crash protection for younger babies.

Booster fit: The OneFit Max does a very good job at positioning both the lap and shoulder belt correctly for booster-aged children. Because of its longer seat shell, parents and caregivers should ensure that their child’s knees bend over the front edge when assessing proper booster fit. In some vehicles, the OneFit Max’s extended seat shell may cause a child’s legs to hit the vehicle’s center console. 

Crash protection: In CR’s crash test protocol, the Chicco OneFit Max performed very well and did not exhibit significant structural integrity issues.

Additional Information

Good to know: All child car seats sold in the United States are required to meet government safety standards. 

About our testing: Consumer Reports’ child car seat tests are not designed to test compliance with federal standards. Rather, we evaluate car seat performance under conditions designed by our experts that go beyond the required federal safety standards. 

Consumer Reports’ independent car seat crash test program has been carefully designed to simulate the forces encountered during a crash, while replicating some of the real-world factors that might impact a car seat’s performance. Our testing aims to determine which car seats could provide an extra level of safety when compared to other models in the same category. 

Basic, Better, or Best: CR rates the child car seats we crash test on a scale of Basic, Better, and Best, based on the additional margin of safety they may provide. Read about how we test car seats to learn more about our crash test protocol.

The Chicco OneFit Max is part of the Car Seats test program at Consumer Reports. In our lab tests, Harnessed Car Seat models like the OneFit Max are rated on multiple criteria, such as those listed below.

Ease of use: Our judgment of how easy each seat is to use including the clarity of labels and instructions, adjustments of clips and buckles, the transition of the seat between modes and installation features such as LATCH connections, belt paths, top tethers and booster guides.

Forward facing fit-to-vehicle: A rating of how compatible, easy and secure a child car seat can be correctly installed in the forward-facing direction. This rating is a combination of the LATCH system and belt ratings that are available individually on the model page.

Rear facing fit-to-vehicle: A rating of how compatible, easy and secure a child car seat can be correctly installed in the rear-facing direction. This rating is a combination of LATCH system and belt ratings that are available individually on the model page.