Evenflo All4Stages Slim+

The Evenflo All4Stages Slim+ offers more features than its slightly less expensive counterpart, the All4Stages Slim, but it’s still a pretty straightforward, no-frills, all-in-one car seat. The seat can be used with kids weighing from 4 lbs. to 120 lbs., and transitions through four modes: rear-facing harnessed, forward-facing harnessed, highback booster, or backless booster. For the price, CR’s testers say it offers just enough ease-of-use features. But our testers noted some issues with getting a proper recline for infants, and when routing the seat belt to install with the seat belt in rear-facing mode (see Detailed Test Results, below).

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)
• Anyone who needs a simple and straightforward installation process, thanks to the push-on LATCH connectors
• Families who need a seat that’s easy to move between multiple cars
• Families who need to fit three car seats across the back seat
• Cars with a small back seat
• Parents of preemies over 4 lbs

Ease of use: The Evenflo All4Stages Slim all-in-one car seat was generally easy to use and scored fairly high in CR’s ease of use tests. There’s not much assembly needed, the headrest, harness, and crotch strap are easy to adjust, and the labels and manual are easy to follow. There was some difficulty in routing the seat belt when used in rear-facing position, and this model is overall not as feature-rich as others we’ve tested, making it somewhat basic.

Fit-to-vehicle LATCH: The forward-facing installation with the LATCH attachments took some effort to adjust, and it wasn’t compatible with the back seat head restraints in several of our tests.

Fit-to-vehicle belt: Installing the car seat in forward-facing position with the seat belt took CR’s testers multiple efforts to get a secure fit, and you may need to remove the back seat head restraint in some vehicles to get a better fit. In rear-facing position, you have to partially remove the car seat cover to effectively route the seat belt strap, which is tedious, and the cupholder positions also make the seat belt routing slightly difficult.

Booster Fit: Overall, this seat’s ability to correctly position the lap and shoulder belts is very good, but in some seating positions the shoulder belt lies further out on the shoulder of our test dummy (designed to reflect the size and weight of an average 6-year old) even with the shoulder belt guide in its highest position. 

Crash protection: In CR’s crash test protocol, this seat showed average performance 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 Evenflo All4Stages Slim+ is part of the Car Seats test program at Consumer Reports. In our lab tests, Harnessed Car Seats models like the All4Stages Slim+ 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.