In Depth Baby Product Reviews Led by a Pediatrician

Diono Monterey 4DXT Review

While the crash test results are impressive, it doesn't offer much and might be too wide for some cars or family requirments
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Diono Monterey 4DXT Review
Credit: Abriah Wofford
Price:  $200 List
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Manufacturer:   Diono
By Juliet Spurrier, MD & Wendy Schmitz  ⋅  Jan 26, 2024
62
OVERALL
SCORE


RANKED
#9 of 14
  • Crash Test - 35% 8.2
  • Ease of Use - 25% 5.1
  • Weight/Size - 15% 5.1
  • Comfort - 15% 4.8
  • Quality - 10% 6.0

The Skinny

The Diono Monterey 4DXT is not our favorite booster seat, and for the price, we kind of expected it to score higher overall compared to the competition. While the crash test results are good and better than most, we think it is lacking in ease of use, comfort, and quality. It is a larger seat that is super wide, and the width made it harder for little ones to reach around and find the vehicle buckle. If you don't need to carry it or fit multiple seats in one car, the size and awkward carry might be acceptable, but it doesn't do anything particularly well beyond the crash test results. We think there are better options with more to offer that might save you some money.
REASONS TO BUY
Better crash test results
REASONS TO AVOID
Very wide
Awkward headrest
Hard to carry
Editor's Note: The Diono Monterey 4DXT was tested and compared to a new lineup of boosters on January 26, 2024.

Compare to Similar Products

 
diono monterey 4dxt
Awards  Editors' Choice Award Top Pick Award Best Value Award  
Price $200 List
$199.99 at Amazon
$160 List
$159.99 at Amazon
$37 List
$29.74 at Amazon
$120 List
$79.99 at Amazon
$29 List
$28.98 at Amazon
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Bottom Line This option is super wide and might be a struggle with multiple kids across one row, so despite the better crash results it wasn't a favoriteGreat choice for most families with better crash testing analysis, easy installation, and cozy seating for kidsGreat for travel and carpooling, but the quality and crash results make it less appealing as an all-the-time boosterA comfy headrest and good crash test results make this lightweight choice an option that won't break the bankThis basic booster offers disappointing results in most metrics, including crash test analysis, making the low price less appealing
Rating Categories Diono Monterey 4DXT Chicco KidFit Zip A... BubbleBum Diono Cambria 2 Graco TurboBooster...
Crash Test (35%)
8.2
8.2
6.5
8.0
5.3
Ease of Use (25%)
5.1
8.3
8.0
5.1
7.5
Weight/Size (15%)
5.1
6.5
10.0
5.9
7.9
Comfort (15%)
4.8
7.3
4.4
6.1
3.2
Quality (10%)
6.0
8.0
3.5
4.0
3.5
Specs Diono Monterey 4DXT Chicco KidFit Zip A... BubbleBum Diono Cambria 2 Graco TurboBooster...
Modes High Back Booster, Backless Booster High Back Booster, Backless Booster Backless Booster High Back Booster, Backless Booster Backless Booster
High Back Booster Weight Range 40-120 lb 40-110 lb N/A 40-120 lb N/A
High Back Booster Height Range 38-63 in 38-57 in N/A 38-63 in N/A
Width 20.7 in 18.2 in 11.3 in 19.9 in 16.3 in
Weight 17.9 lb 11.8 lb 0.9 lb 12.0 lb 4.5 lb
Backless Booster Height Range 38-63 in 38-58 in 40-57 in 38-63 in 43-57 in
5 Point Harness Weight Range N/A N/A N/A N/A N/A
5 Point Height Range N/A N/A N/A N/A N/A
LATCH Equipped Yes Yes No Yes No
#REF! #REF! #REF! #REF! #REF! #REF!
Recline Positions None 2 N/A None N/A
Foam Type EPS + EPP EPS None None None
Seat Lifespan 8 Years 8 Years 4 Years from purchase date 8 Years 10 Years
Aircraft Certified

Our Analysis and Test Results

Diono began in Seattle, Washington, in the late 90s. Shortly after launching, they won an award that inspired them to make more safety seats and to start a branch in England. They went on to launch the first steel-reinforced folding seat. To increase growth and continue designing innovative safety seats, Diono accepted investment from Winona Capital in 2015.

Performance Comparison



The Monterey performed well in our commissioned crash test with MGA Research. This third party, hotter than the federal guidelines testing, resulted in one of the highest analysis results.
Credit: GearLab & MGA Research

Crash Test


The Monterey managed to outperform other Diono boosters we tested with a higher-than-average result that puts it in the top tier of results.


This analysis of the combined sensor data from the HIC and chest clip sensors indicates a potential for an additional margin of safety over the average seat.

The Monterey (in black) has similar HIC sensor data results to one...
The Monterey (in black) has similar HIC sensor data results to one of the best in the group, the Peg Perego (in green).
The chest clip sensor data of the Monterey (in black) is similar to...
The chest clip sensor data of the Monterey (in black) is similar to the results from the Peg Perego (in green). The Peg is one of the highest-performing boosters in the group.

All of the options in this review should pass federal guidelines and are considered safe. However, we ran our test a bit faster and used a stiffer sled to mimic late-model vehicles. We hoped to identify those seats that perform better than the rest. The Monterey offered some of the best HIC and chest clip sensor results in the lineup with lower recorded g-forces, where lower is better.

The Monterey shoulder positioner is easy enough to thread, but as you raise the headrest, it can bring the belt closer to the passenger's neck.
Credit: Abriah Wofford

Ease of Use


The Monterey is not that easy to use and scored below average for the group. This booster was significantly harder than most to get the belt buckled because of the width and the shape.

We did not have trouble threading the shoulder belt on the Monterey.
We did not have trouble threading the shoulder belt on the Monterey.
The seat bottom design on the Monterey can make it more challenging...
The seat bottom design on the Monterey can make it more challenging to buckle the seat belt.

Our tester and helping adult struggled to get the seat out of the way to reach the buckle, and it was made all the more difficult with a child in the seat. The shoulder positioner works well, but as you extend the headrest up, it could bring the belt closer to the passenger's neck.

The Monterey has hook-style LATCH connectors to secure the booster...
The Monterey has hook-style LATCH connectors to secure the booster to the anchors and prevent it from flying about.
There is a LATCH strap release under the seat bottom on the Monterey.
There is a LATCH strap release under the seat bottom on the Monterey.

Installing the seat was also not straightforward with hook LATCH connectors and trouble getting the strap snug as the back wings collided with the vehicle seat. We got it done, but it wasn't user-friendly at all, and it really should have been since it was just securing the booster to the car.

The Monterrey has dual cup holders that slide out from the seat bottom and our Thermos test bottle fits in without room to spare.
Credit: Abriah Wofford

The Monterey has two slide-out cup holders you might not even notice. We like that they can be folded in for space since the seat is already so wide, and we like that our test water bottle fit.

diono monterey 4dxt - while the monterey is heavier than the average booster, you can...
WHile the Monterey is heavier than the average booster, you can remove the back to make it lighter for occasional travel.
Credit: Abriah Wofford

Weight and Size


This seat is heavy for a booster and is more comparable to the convertible car seats we've tested. It weighs 17.9 lbs, which is above the average for the group.


The width is also somewhat prohibitive, depending on your situation. At 20.7 inches wide, there aren't many that are wider. Not only is this a potential challenge for multiple seats across, but it can also make accessing the buckle for little ones more of a challenge as it can cover the area kids need to reach.

The Monterey has adjustable side wings to help find a good fit for most kids.
Credit: Abriah Wofford

Comfort


Comfort is not a strong suit for the Monterey compared to the competition. It scored below average in this metric and was not a preferred option by our kid testers. The comfort padding reminds us of packing material, and it has little give or bounces back when you press on it. While it is marginally better than hard plastic, it isn't great. Our kid tester likened it to “hard wood” when sitting in it.

diono monterey 4dxt - the headrest on the monterey is wider than average and could cause...
The headrest on the Monterey is wider than average and could cause neck pain if the passenger's head falls at a harsh angle while napping.
Credit: Abriah Wofford

The fabric feels soft at first and our little tester really liked it. However, we suspect over time, it might lose this smooth and soft feeling as things can get caught in the weave. We didn't like it as much at the end of testing as we did in the beginning.

The Monterey's fabric feels soft, but the weave pattern makes us...
The Monterey's fabric feels soft, but the weave pattern makes us worry it will collect debris and be less soft over time.
Only a couple of boosters offer the wing adjustments we see on the...
Only a couple of boosters offer the wing adjustments we see on the Monterey and we think it is pretty cool to accommodate children of all sizes.

The headrest has a weird design shape, and there is a bump in it that results in the child's head jutting forward and resting at an odd and uncomfortable angle. We could get this shape to change, and it is either an intentional choice to a quality control issue, but either way, we suspect it will impact the comfort of longer drives.

We kind of like the slide-out cup holders on the Monterey, and you might even miss them if you don't know they are there.
Credit: Abriah Wofford

Quality


The quality performance of the Monterey is slightly above the average for the group. While it might not have giant red flags, for the price, we'd want more. The padding overall is lacking in makeup and placement. The fabric might be soft, but the cover is friction-fitted into a slot on the torso area of the booster, and it has hook and loop (Velcro) connections in other areas. It is generally average compared to other boosters and is neither exceptional nor hugely disappointing.

diono monterey 4dxt - other than a better crash test analysis result, we didn't find much...
Other than a better crash test analysis result, we didn't find much to love in the Monterey and think there are likely better options for most families.
Credit: Abriah Wofford

Should You Buy the Diono Monterey 4DXT?


While the Monterey has a cool look and feel, and we get the appeal when you take a first look, it didn't impress enough in testing to make it a stand-out option in our minds. In fact, other than better crash test analysis results than much of the group, it didn't fare well in our other performance metrics like ease of use or comfort. While crash testing is important, to be sure, in this lineup, you can find other options with better crash test analysis, higher metric scores overall, and cost less. Because there are better options, we think there are better options out there.

What Other Booster Seat Should You Consider?


One of the best options in the group is the Chicco KidFit Zip Air Plus 2-in-1. This booster is less expensive than the Monterey, and it has better crash test analysis results. It also has higher-than-average results in all of the remaining metrics. We love the ease of use and the leg lounger feature for added comfort. If you want the best crash test results, the Peg Perego Viaggio Flex 120 is also one to consider. While the Peg is one of the higher-priced options in the group, it performed very well in all metrics and is a standout no matter what your booster goals might be (outside of travel).

Manufacturer Video



Juliet Spurrier, MD & Wendy Schmitz