Graco SlimFit3 LX 3-in-1 Car Seat Review: A Mom’s Honest Thoughts

Editor's Rating:

For parents who have more than one child, or families with smaller cars, it quickly becomes clear that convertible car seats can be large, bulky, and difficult to maneuver. Fortunately, there are a number of great car seat models, like the Graco SlimFit3 LX 3-in-1, that are durable, comfortable, and slim enough to fit three-across in the back seat. Read on for my honest Graco SlimFit3 LX 3-in-1 car seat review, complete with all the features we’ve come to love (and not love) from using this car seat with our two young children.

Graco SlimFit3 LX 3-in-1 Car Seat: Our Family’s Experience

Graco SlimFit3 LX 3-in-1 Car Seat Review

When our son grew out of his newborn car seat, the first convertible car seat we purchased was the popular Graco Extend2Fit, which we chose for its consistent high reviews, top safety ratings, and significant leg room.

Although we loved the Extend2Fit, we wanted something narrower for our second convertible car seat. We settled on the Diono Radian 3QX. I love our Diono, but it’s expensive, heavy, and difficult to clean. Read my full review of the 3QX here.

Over the past few months, we realized we needed another car seat that we could switch between cars or have grandparents use. After some significant research, we chose the Graco SlimFit3 LX 3-in-1, due to its narrow width, light weight, high safety ratings, and user-friendly features.

If you’re considering the SlimFit3 LX 3-in-1, you should be aware that the Graco SlimFit 3-in-1 is a completely different car seat with much wider dimensions, despite its similar name.

Pros and cons

Graco SlimFit3 LX 3-in-1 Car Seat Review

Here are some of the features we love about the SlimFit3 LX, and a couple with room for improvement:


  • Families can start out with the SlimFit3 right from the newborn days, with a child weight range from 5 to 100 pounds.
  • Graco has gone above and beyond federal standards to ensure the integrity of the SlimFit3’s materials in extreme temperatures, and to test the safety of the car seat in the case of a front, rear, side, or rollover crash.
  • The LX is FAA-approved for use in flight.
  • The width of the SlimFit3 LX is less than 17″ overall, making it compact enough to fit three across in the back seat of most vehicles.
  • With a weight of 19.2 pounds, it’s been manageable for us to switch the LX between cars or remove it for cleaning.
  • The seat fabric is easy to remove and throw in the washing machine, even without uninstalling the car seat.
  • It’s easy to adjust the headrest and harness strap height from one child to the next, without having to remove the seat pad or rethread the straps.


  • Although its 19.2-pound weight is lighter than some competitors, it’s heavier than many travel car seats, and it may be difficult to carry through the airport if using it for air travel.
  • The SlimFit3 LX is a rather upright car seat, making it less comfortable for longer road trips.

Detailed Features and Specifications

To help you decide if the SlimFit3 LX 3-in-1 should be your next car seat purchase, we’ve detailed everything you need to know before adding to cart:


Graco SlimFit3 LX 3-in-1 Car Seat Review

The Graco SlimFit3 LX 3-in-1 car seat certainly doesn’t qualify as a budget buy. It costs approximately $280, depending on the retailer. This puts it in the middle of the road compared to Graco’s other car seats, which range anywhere from around $100 to almost $500. In comparison, the SlimFit3 is considerably more affordable than our slim Diono Radian 3QX, which has a price tag close to $400.

Child weight range

Graco SlimFit3 LX 3-in-1 Car Seat Review

With convertibility from a rear-facing car seat to a forward-facing car seat and eventually a highback booster, Graco designed the SlimFit3 LX 3-in-1 to last from the newborn days through young childhood.

In the rear-facing position, the LX accommodates babies from 5 to 40 pounds in weight, and up to 49 inches in height. Once parents switch the car seat to the forward-facing position (which should be sometime after age two), the car seat is appropriate for children between 22 and 65 pounds, and also up to 49 inches in height. When children exceed the weight limit for the LX in the forward-facing position, parents can convert it to a highback booster seat, which is safe for kids weighing up to 100 pounds.

With two toddlers weighing 43 and 27 pounds, and a newborn joining our family in the next few months, a convertible car seat like the SlimFit3 LX offers us the flexibility to use it for any of the three kids. It’s an enduring purchase that should last our family years to come.

Safety features

Graco SlimFit3 LX 3-in-1 Car Seat Review

Crash testing and safety features are always the most important details I look at before deciding on a car seat.

The SlimFit3 LX, like all of Graco’s car seats, meets the United States Motor Vehicle Safety Standard (US MVSS) 213. It is also backed by the promise of Graco ProtectPlus Engineered car seats, meaning that it has successfully passed testing above and beyond what is required by the US MVSS 213.

In all its crash test scenarios, Graco employs speeds and forces that are approximately twice as strong as those required by the federal standard. Even though there are no federal requirements for side-impact testing, rear-impact testing, and rollover accident testing, Graco employs all three in its safety certification for the SlimFit3 LX. The brand has also ensured that the car seat’s materials maintain their integrity in extreme hot and cold temperatures — conditions that typically make materials more brittle and prone to damage.

Finally, the SlimFit3 LX has a steel-reinforced frame with energy-absorbing foam, making it durable and energy-efficient. Graco warns parents that they should discard the car seat 10 years after the date of its manufacture.

Car seat size and weight

Graco SlimFit3 LX 3-in-1 Car Seat Review

True to its name, one of the considerable draws of the Graco SlimFit3 LX 3-in-1 car seat is its slim profile. Overall, it measures 20.7″ long by 16.7″ wide by 24.5″ high. It’s even narrower than our Diono Radian 3QX, a competing car seat known for its compact base.

Graco advertises the SlimFit3 LX as being compact enough to fit three across in the back seat. This selling point was the major reason we decided on the SlimFit3 LX rather than purchasing a second Graco Extend2Fit. If the SlimFit3 LX doesn’t fit with its cup holders attached, it’s easy for us to remove them from either side of the car seat.

The 19.2-pound weight of the SlimFit3 LX is also a major advantage. Many car seats are bulky and heavy. Our Diono, for example, weighs 31.3 pounds, making it difficult for me to switch cars or clean the car seat on my own (especially in my current seven-months-pregnant state!). We’ve found the SlimFit3 to be ideal for grandparents and for situations where we need to move the car seat around more frequently.

Comfort and adjustability

Graco SlimFit3 LX 3-in-1 Car Seat Review

The SlimFit3 LX 3-in-1 has thick padding throughout and soft harness pads over the shoulders. I love Graco car seats because they have a wraparound head rest that adds extra safety and comfort for the head and ears.

There have been many times when we’ve pulled the kids out of the car, only to be surprised by how warm and sweaty they are against the seat back of other car seats. The SlimFit3 helps prevent this with breathable mesh airflow channels along either side of the seat.

The seating area of the SlimFit3 is wide and ample, despite its narrow footprint. A plush, removable insert helps to cradle the head and body of younger babies.

One of the best parts of the SlimFit3 LX is how easy it is to adjust the fit between children, or to adapt to little ones growing taller. The head rest and harness height are both adjustable to 10 different heights with just one hand. The harness uses no-rethread technology, meaning we are saved from the headache of uninstalling the car seat and redoing the straps every time we need to fine-tune them.

Having four recline positions to choose from is definitely an advantage of the SlimFit3 over other slim-line car seats, but I do wish that we could recline the seat to a greater degree. In our experience, its upright seat back is this car seat’s most significant drawback. It doesn’t recline nearly as far as our Diono Radian or as our Graco Extend2Fit.

We recently went on a five-hour road trip with our two kids using the SlimFit3 LX for our 18-month-old daughter. As is typical for us, we decided to drive at night so our kids would sleep in the car. Every time our daughter started to doze off, her head would fall forward, putting her in an uncomfortable position with her chin nearly resting on her chest. I ended up sitting in the back next to her and holding her head up for nearly the entire trip so that she could sleep soundly.


Graco SlimFit3 LX 3-in-1 Car Seat Review

Like other Graco car seats that we’ve tried, installing the SlimFit3 LX is relatively simple.

In both the front-facing and rear-facing positions, the LX secures to the back seat using the seatbelt or the car’s latch installation hardware, which is a required component of any car manufactured in 2003 or later. The car seat has a buckle on each side that snaps into the vehicle’s latch hardware with an audible click, so there’s no confusion as to whether the seat is secured. It’s then easy to pull tight and fasten the car seat into place.

The car seat’s manual has specific guidelines for whether the product is installed and adjusted correctly for its precious passenger.

Care and cleaning

Graco SlimFit3 LX 3-in-1 Car Seat Review

Before purchasing our first car seat, I didn’t realize how important it is that the fabrics are easy to clean. Whether or not you have a child who’s prone to getting car sick, accidents are impossible to avoid. Even without major spills, the inevitable buildup of Cheerios, crackers, and other mysterious crumbs will dirty the car seat over time, making regular cleaning a requirement.

Out of all the car seats we’ve tried, the Graco SlimFit3 LX 3-in-1 is by far the easiest to clean. The fabric overlaying the seat can be removed quickly, without undoing any of the harness straps or even uninstalling the car seat! This is especially clutch for when we are tight on time, or when we have multiple car seats installed and don’t want to remove them all to clean up one mess.

The seat pad is safe to throw in the washing machine and hang to dry. For a deeper clean, the harness straps, plastic parts, and metal hardware can be cleaned with mild soap and a damp cloth. The manufacturer warns against soaking the car seat’s harness straps or latch straps underwater.


Graco SlimFit3 LX 3-in-1 Car Seat Review

The SlimFit3 LX 3-in-1 car seat features clean lines and simple colors without gimmicky logos or busy patterns. The seat comes in three dark hues, including two shades of gray as well as a deep plum. Although I love the soothing purple tone, we opted for the dark gray color to keep the aesthetic more gender-neutral.


The SlimFit3 LX 3-in-1 comes with two cup holders that can be installed on either side of the seat. Cup holders might seem like a minor detail, but we’ve found them to be extremely useful to hold drinks, snacks, and small toys for our kids.

The cup holders snap into place with an audible click. They can be removed while the car seat is still installed to make room for more car seats on either side.

The car seat also comes with a cushioned infant insert that provides added comfort and safety for younger babies.

The Upshot: My Honest Graco SlimFit3 LX 3-in-1 Car Seat Review

Graco SlimFit3 LX 3-in-1 Car Seat Review

Overall, I’m happy that we decided on the Graco SlimFit3 LX 3-in-1 car seat for our family. Since it’s lightweight and narrow, it’s an excellent choice for parents who need to fit three car seats across in the back seat, or for caretakers who might need to remove the car seat from the car frequently. The SlimFit3 LX is compact, comfortable, safe, easy to install, and easy to clean.

For more helpful car seat content, check out our roundup of the best FAA-approved car seats, or our reviews of the Diono Radian 3QX, the Cosco Scenera Next, or the UPPAbaby Mesa and Nuna Pipa.

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