---
product_id: 34519510
title: "Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx"
brand: "cosco"
price: "€ 370.04"
currency: EUR
in_stock: false
reviews_count: 11
url: https://www.desertcart.ie/products/34519510-cosco-mighty-fit-65-dx-convertible-car-seat-heather-onyx
store_origin: IE
region: Ireland
---

# Convertible rear & forward modes Lightweight 12.76 lbs Built-in side-impact protection Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx

**Brand:** cosco
**Price:** € 370.04
**Availability:** ❌ Out of Stock

## Summary

> 🛡️ MightyFit 65 DX: Safety, comfort, and convenience that grows with your child!

## Quick Answers

- **What is this?** Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx by cosco
- **How much does it cost?** € 370.04 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/34519510-cosco-mighty-fit-65-dx-convertible-car-seat-heather-onyx)

## Best For

- cosco enthusiasts

## Why This Product

- Trusted cosco brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Space-saving design:** Compact rear-facing size frees up front legroom & fits 3 across most back seats
- • **Easy-care premium fabric:** Machine washable & dryer safe for stress-free cleanup
- • **Fits from newborn to toddler:** Supports 5-65 lbs with rear (5-40 lbs) and forward-facing modes
- • **Travel-ready & aircraft certified:** Lightweight and FAA-approved for seamless family adventures
- • **Effortless front harness adjustment:** 5 heights & 3 buckle positions adjustable from the front for perfect fit

## Overview

The Cosco Mighty Fit 65 DX Convertible Car Seat is a versatile, FAA-approved child safety seat designed for infants and toddlers from 5 to 65 pounds. Featuring a compact rear-facing profile that maximizes legroom and fits three seats side-by-side, it offers built-in side-impact protection and a 5-point harness adjustable from the front. Lightweight and easy to install, its plush, machine-washable fabric ensures comfort and convenience for busy families on the go.

## Description

Get the car seat that’s designed with your family’s real life in mind. The Cosco Kids™ MightyFit™ 65 DX Convertible Car Seat keeps your child safer in the car all the way from 5-65 pounds. It’ll keep your baby comfortably rear facing up to 40 pounds, and then transitions to forward-facing mode up to 65 pounds.Not too big and not too small, the MightyFit 65 DX is designed to be the right size. In rear-facing mode, it takes up less room, which gives parents more leg room in the front seats. The car seat will also fit three across the back seat of most vehicles, which is great for growing families.MightyFit 65 DX keeps kids safer with Side Impact Protection built right in, and a 5-point harness that adjusts easily from the front of the seat. The harness features 5 heights and 3 buckle locations so you can be sure you’re giving the best fit to your growing child.The MightyFit 65 DX Convertible Car Seat is mighty comfortable for kids and convenient for parents too. Kids will love the plush padding and deluxe materials that give them an extra comfy ride. You'll love that the fabric is both machine washable and dryer safe, making this seat super easy to clean when messes happen.If your chosen vehicle happens to be an airplane, this convertible car seat has got you covered. Certified for use on aircraft, it gives your child a familiar seat during the flight. Its compact design also makes it easier to manage through airport security checks.The MightyFit 65 DX is proudly made by Cosco Kids™ in Columbus, Indiana. Made by American families for American families.

Review: Works great - Great value. I bought this seat for when the grandbaby comes over. She is 32 lb. This is a great seat that should last for years. Not bulky. Easy to take in/out. I use the latch system which is easy. Install it only when needed. Once you practice, you can install in under a minute.
Review: Great for the price - In terms of cost, I think this is a pretty great, basic car seat. There’s no fancy “bells and whistles” included that some other models may have, but it does have a cup holder, and a headrest that is easily adjustable. We’ve had this car seat for about a year now and it’s held up perfectly. Easy to clean, travel with, and secure into your vehicle. We’ve only ever secured it with the seatbelt. Pros: The Onyx color is lovely, we didn’t want anything too bright or flashy and the color in person matches the picture. It seems comfy, I’ve obviously never used it personally, but my daughter has never seemed to have an issue. Lightweight. Pretty compact in size compared to others, we have a very small vehicle (Chevy Spark) and this fits pretty well without looking very bulky. Although, it doesn’t fit in rear facing position without moving the passenger seat as far up as possible. Cons: The straps twist constantly in the bucke part. I don’t know if I’m doing something wrong, but I can’t seem to stop it from happening.

## Features

- With two modes of use, this extra-comfortable LATCH-equipped Cosco Kids car seat accommodates infants from 5 pounds up to toddlers weighing 40 pounds in rear-facing mode and kids up to 65 pounds in forward-facing mode.
- The five-point harness adjusts easily from the front of the seat and features five heights and three buckle locations.
- Built-in side-impact protection keeps your little one extra secure. Designed to be just the right size, the seat takes up less space while rear-facing so parents can have more leg room.
- Three of these seats can fit side-by-side in the back seat of most cars, perfect for growing families.
- With plush padding and premium fabric, this seat gives your child an extra-comfy ride. Easy to clean, the fabric car seat cover is machine-washable and dryer-safe.
- This car seat meets or exceeds federal, ASTM, and JPMA safety standards and includes a one-year limited warranty.
- For more than 70 years, Cosco Kids has been a leading children’s products brand recognized for its dedication to safety and value. From bouncers to car seats, swings to strollers, and high chairs to play yards, Cosco Kids's essential baby products feature solid value and smart design.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01ETUBQZ4 |
| Age Range Description | Less than 18 months |
| Best Sellers Rank | #27,755 in Baby ( See Top 100 in Baby ) #71 in Convertible Child Safety Car Seats |
| Brand | Cosco |
| Color | Onyx |
| Customer Reviews | 4.4 4.4 out of 5 stars (2,930) |
| Forward Facing Maximum Weight | 65 Pounds |
| Forward Facing Minimum Weight | 22 Pounds |
| Global Trade Identification Number | 00884392609382 |
| Harness Type | 5-Point |
| Installation Type | Latch |
| Item Dimensions D x W x H | 17"D x 22"W x 23.5"H |
| Item Weight | 5.8 Kilograms |
| Manufacturer | Cosco |
| Material Type | Fabric |
| Maximum Height Recommended | 30.5 Inches |
| Maximum Weight Recommendation | 40 Pounds |
| Minimum Height Recommendation | 19 Inches |
| Minimum Weight Recommendation | 5 Pounds |
| Number of Height Positions | 5 |
| Orientation | Forward Facing, Rear Facing |
| Rear Facing Maximum Weight | 40 Pounds |
| Rear Facing Minimum Weight | 5 Pounds |
| UPC | 884392609382 |
| Unit Count | 1.0 Count |

## Product Details

- **Brand:** Cosco
- **Color:** Onyx
- **Installation Type:** Latch
- **Material:** Fabric
- **Orientation:** Forward Facing, Rear Facing

## Images

![Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx - Image 1](https://m.media-amazon.com/images/I/812sCyl5SUL.jpg)
![Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx - Image 2](https://m.media-amazon.com/images/I/81aWi1B+0SL.jpg)
![Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx - Image 3](https://m.media-amazon.com/images/I/61tYxXIVkqL.jpg)
![Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx - Image 4](https://m.media-amazon.com/images/I/81oMxtrn90L.jpg)
![Cosco Mighty Fit 65 DX Convertible Car Seat, Heather Onyx - Image 5](https://m.media-amazon.com/images/I/8191lKaznEL.jpg)

## Available Options

This product comes in different **Color, Style** options.

## Questions & Answers

**Q: Which is better for air travel, mightyfit 65 or scenera next?**
A: I have traveled with might fit 65 internationally and it's fine. The seat is very light weight, but scenera is lighter. However, I gate checked the mightyfit on my return trip and the seat had minor cracks. But that's on the airline and me, any car seat is prone to damage because of mishandling.

**Q: Will this fit 3 across in a 2016 Dodge Caravan?**
A: I think it would. It leaves enough space in the back of my Rogue for an adult to sit between it and the booster seat for my older child. I used to have a caravan and there was a lot more seat space in it.

**Q: Can this seat be used in the middle of the backseat?**
A: Yes

**Q: How does the cover attach? Does it have those super annoying elastic strings to keep the cover in place? Those always stretch out and fail!**
A: Thank you for your question. The cover on the Cosco Mighty Fit 65 DX Convertible Car Seat attaches with elastic straps.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works great
*by M***E on November 22, 2025*

Great value. I bought this seat for when the grandbaby comes over. She is 32 lb. This is a great seat that should last for years. Not bulky. Easy to take in/out. I use the latch system which is easy. Install it only when needed. Once you practice, you can install in under a minute.

### ⭐⭐⭐⭐⭐ Great for the price
*by J***N on August 29, 2017*

In terms of cost, I think this is a pretty great, basic car seat. There’s no fancy “bells and whistles” included that some other models may have, but it does have a cup holder, and a headrest that is easily adjustable. We’ve had this car seat for about a year now and it’s held up perfectly. Easy to clean, travel with, and secure into your vehicle. We’ve only ever secured it with the seatbelt. Pros: The Onyx color is lovely, we didn’t want anything too bright or flashy and the color in person matches the picture. It seems comfy, I’ve obviously never used it personally, but my daughter has never seemed to have an issue. Lightweight. Pretty compact in size compared to others, we have a very small vehicle (Chevy Spark) and this fits pretty well without looking very bulky. Although, it doesn’t fit in rear facing position without moving the passenger seat as far up as possible. Cons: The straps twist constantly in the bucke part. I don’t know if I’m doing something wrong, but I can’t seem to stop it from happening.

### ⭐⭐⭐⭐ Comfy, basic, difficult to install rear-facing
*by B***. on February 15, 2017*

This seat is plush and cool, so my kids are very comfortable in it. The materials are great, the size is perfect, the safety ratings are reassuring, and the price is amazing! This is a bare bones seat, though. It has no convenience features like an easily adjustable no-rethread harness, or a level so you angle is correct. However, that is reflected the VERY affordable price (about $85) The only issue I have with this seat is that it is a huge pain to install it correctly and securely in a rear facing orientation, especially if you have deeply contoured seats. PROS: - Great rear facing height and weight limits - Higher forward facing weight limit than almost any other seat in this price range, allowing your bigger kid to stay in a harness longer. My 4 year old is almost 45 pounds, so this 65 pound forward facing limit will allow him to stay on a harness for a few more years, until he is ready for a belt positioning booster. - Relatively compact size, with straight sides that make it easier to fit next to another seat. - Comfortable, cool fabric. Won't absorb heat like a dark seat if you live somewhere hot. - Plush seat! - Machine washable cover. - Cute styling! I got the aqua blue for both my son and daughter and they love it. - Easy forward facing install. - Lightweight and easy to carry for travel. CONS: - Difficult to get a tight installation rear facing. - Does NOT fit 3 across in a Jetta. - Tedious to rethread the straps and adjust the headrest. - The button you have to push to loosen the straps is buried under the cover and not marked, so it isn't easy to find and use. All in all, this is a great basic seat for the money! I use them as travel seats and back ups in our second car. This seat won't work well for someone who needs to use it for different children, as it must be removed from the vehicle to adjust the headrest and strap heights. It also wouldn't be ideal if you were going to be moving it from one car to another frequently, as the install isn't as quick and easy as it is on models with more convenience features. But it's safe and sturdy and does its job, and you really can't beat it for this price!

## Frequently Bought Together

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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-03-19*