Diono Monterey Review

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*This seat has been replaced with the Monterey XT.* When Diono announced the re-release of the Diono Monterey booster, we rejoiced!  The Diono Monterey is a favorite among many of the CSFTL older Littles. With a variety of both ease of use and comfort features, it’s a great option for when older children are ready to transition to a booster.

Diono Monterey

Diono Monterey

CSFTL Quick Stats

  • Highback booster weight range: 40-120 lbs.
  • Highback booster height range: 38-63″
  • Backless booster weight range: 40-120 lbs.
  • Backless booster height range: 38-63″
  • Highest booster guide position: 21″
  • Hook on lower anchor connectors
  • Older versions have a 6 year expiration, newer ones are 8 years (check the manual)
  • 2011 IIHS Best Bet in high-back mode
  • Requires vehicle head restraint support in both modes


When the Monterey showed up on my doorstep, it was like welcoming an old friend into our house.  The Monterey was the first booster my oldest daughter used and our family has liked the seat ever since.  The Monterey is shipped in two pieces.  Assembling the Monterey is straightforward — line up the back of the booster with the bottom, and snap the high-back portion into place.



Lower Anchor Connectors

Diono Monterey lower anchor connectors


One of the main features of the Monterey is the ability to use lower anchor connectors to install the seat. Many caregivers appreciate this feature as the lower anchor connectors attach the booster to the vehicle and removes the risk of the seat becoming a projectile in a crash when it’s unoccupied.  There are no weight limits when using the lower anchors with a booster; using them restrains the weight of the booster and not the child.


Diono Monterey seat adjustments.

Diono Monterey seat adjustments



The Monterey features 11 different headrest positions, ranging from 14.5 inches to 21 inches to provide a proper fit as the child grows.  The torso wings adjust width wise to accommodate the broader shoulders of older children. At its most narrow adjustment, the Monterey measures 19.5 inches wide and can expand up to 22.5 inches at the widest.



Diono Monterey dual cupholders


The Monterey boasts not just one, but two cup holders. They can be tucked away when not in use or if you need to install a car seat next to it. Without the cupholders, the seat measures 18 inches wide. With the cupholders out, the seat width increases to 22 inches.
The Monterey’s comfort features can appease even the pickiest of booster riders. With ample padding, soft fabrics, and enough depth to keep even the longest-legged kids supported, the booster is easy to love. The seat depth measures 14 inches while the width at the thighs is 16 inches making it a good choice for bigger kids.


Installation and Usage

Using and installing the Monterey is easy.  If lower anchors are not available, the seat can be used without them. Remember to buckle the seat in when it’s not in use thought when the lower anchors are not in use!  To use the lower anchors, loosen the connector strap using the adjustment lever located on the front of the seat, attach the lower anchor connector to the designated points in your vehicle, and pull the straps tight from the front of the seat.  Unlike a harnessed seat, there doesn’t need to be less than one inch of movement side to side when installed. The Monterey does require head restraint support from the vehicle to the top of the child’s ears, even in high-back booster mode.  This may rule out the Monterey as an option for those vehicles with low seat backs and no head restraints.

Diono Monterey lower anchor lever and button

Diono Monterey lower anchor lever and button


I did notice the buttons on the lower anchor adjuster straps can get stuck in the adjuster.  If they do, it can make it difficult to release and adjust properly.  When tightening the lower anchors, make sure to not pull them in too far, to ensure they don’t get stuck. Loosen the straps by pressing down on the silver lever and pull the connector straps.

Diono Monterey belt guide

Diono Monterey belt guide


One major improvement that came with the re-release of the Monterey was the updated belt guide for the shoulder belt. Before the re-design, the belt guide made it difficult to allow the belt to retract if the child leans forward or when buckling themselves in. This issue has been remedied and the belt retracts freely.


Fit to Child

Not only does the Monterey offer a variety of comfort and ease of use features, it also provides a great belt fit for a range of booster riders.  The shoulder belt rests nicely on the collarbone, and the lap belt sits nice and low on the lap.

High Back Mode

Diono Monterey, 5 years old, 52 lbs, and 46 inches tall

Diono Monterey, 5 years old, 52 lbs, and 46 inches tall


The first model is 5 years old, 52 lbs, and 46 inches tall.  She’s a newer booster rider, but was pleased with the comfort of the Monterey and especially the cup holders.  She can easily buckle the belt by herself, though I still check to make sure it’s in the correct position. At 5, it’s important to remind kids of the rules of booster riding — sitting still, not wiggling out of place, and staying upright even when asleep.


Diono Monterey, 8 years old, 56 lbs, 52 inches



The next model is 8 years old, 56 lbs, and 52 inches. She’s quite the experienced booster rider and was happy to see the Monterey back.  She was pleased with the comfort and softness of the seat’s cover.  Like her little sister, she could easily buckle the seat herself and the booster provided an excellent belt fit. She’s picky about leg support on her seat.  She was happy to discover that the Monterey still provided ample support like the previous version did.


Diono Monterey- 10 years and 75 pounds

Diono Monterey, 10 years old and 75 lbs


Model number three is 10 years old and approximately 75 lbs and 54 inches. The Monterey fits bigger children quite nicely with ample room for broader shoulders and taller torsos. The Monterey still provides excellent seat belt fit on this older model, seat belt crosses nicely across her collar bone and the belt is low on her lap and not on her abdomen. At 10, she is getting closer to passing the five step test, but she’s not quite there.



Backless Mode

Diono Monterey backless mode, 8 years old, 56 lbs, 52 inches

Diono Monterey backless mode, 8 years old, 56 lbs, 52 inches


The Monterey can also be used as a backless booster. It was sold separately in the past as the Santa Fe, but Diono did not re-release the Santa Fe when they released the Monterey. The similar backless Diono Solana is available. The Monterey provides a great seat belt fit for older children as well when using it backless. Children always require vehicle head restraint support to the tops of their ears when using the seat in backless mode.


The model for the backless booster is 8 years old, 56lbs, and 52 inches.  As a backless booster, the Monterey is a lightweight booster which could make it a good option for car pooling or travel.


Important Information: Where to Find

FAA approval  Since airplanes only have lap belts, and boosters can only be used with lap and shoulder belts, the Monterey is not FAA approved.  As a backless booster, it would be good to tuck into the overhead bin or below the seat, and use upon arrival at your destination.

Diono Monterey Date of Manufacture sticker


Expiration  The date of manufacture along with the model number can be found on a sticker on the bottom of the seat.  Older versions expire in 6 years, newer ones in 8 years (check the manual).

Diono Monterey manual storage


Manual Storage  The manual for the seat is located on the bottom of the seat. This is a great place to find answers to questions to like replacement after a crash. The Monterey follows the NHTSA guidelines for replacement after a crash.


  • Lots of head/torso support
  • Wide and deep seating area
  • Has lower anchors
  • Adjustable back support fits a variety of builds


  • Requires a vehicle headrest behind it.


Overall Thoughts

The Monterey is a long-lasting, well-fitting booster.  Along with providing most children an excellent seat belt fit, it has many ease of use and comfort features and lower anchors. Like our family, many families will get a lot of use out of the Monterey, both in their own vehicles and when traveling.



Diono provided CSFTL with the Monterey for review, but no other compensation was given.Our friends at Diono are offering one lucky winner a Monterey of their own!  Simply enter in the Rafflecopter below.





a Rafflecopter giveaway


Originally written by Kim Robinson. Edits maintained by CSFTL.