Britax Marathon 65 Convertible Car Seat Reviews

The Britax Marathon 65 convertible car seat:

A Comprehensive Review from experienced consumers. Read about the Pros and the Cons and where to get the best price for this safety seat.

britax marathon 65 convertible car seat review

Table of Contents for the Britax Marathon 65: (Jump ahead!)

- Safety
- Best Price

- Comfort

- Ease of Strap Adjustments

- Ease of Installation

- Customer Reviews

- Plus detailed Photos!

I spent WEEKS researching car seats.

Click here to check out daily 20%-60% discounts on Amazon for these car seats for today:

Sales are subject to change daily!

After spending weeks researching car seats, I narrowed down my choices to a few of the top-rated seats, and the Britax Marathon 65 is one of the best convertible car seat. I’ve compiled my notes below for your convenience, and also included links to my reviews of the other car seats in the right sidebar.

This is a convertible car seat, which means you can use it from newborn until your child weighs fifty pounds – and you will get many years of use out of this investment. In the rear-facing position, your baby must weigh 5-35 lbs, and when it is positioned forward-facing, your child can be in the 20-65 lbs. range, so this will last most kids well into first grade. The maximum height is 49″, and seated shoulder height is up to 16″.

This seat is 19.5 inches wide and measures 25.5 inches tall in the back, so it is a hefty seat. Do not plan on having 2 Britax seats in your back row and still fitting a third passenger in the same row comfortably. (Someone very thin will be okay for a short ride in that middle space!)

Note: There is an updated version of this product, the Britax Marathon 70 convertible car seat. This Marathon 65 is still available, although the Marathon 70 is the newest model of the Britax Next Generation car seats.

Britax Marathon Convertible Car Seat Safety:

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britax Marathon convertible car seat safety

My first and foremost concern when choosing a car seat was obviously safety. One of the first things I did in my research was pay for access to the Consumer Reports site and find that the Britax Marathon was one of their top-rated convertible car seats.

Testimonial from a parent on Amazon: “My husband, 21 month old son, and I were just rear ended HARD a few minutes ago….and the seat performed perfectly…not only was my son well protected and cushioned from the impact, but he even seemed a little bored…not a peep. Great seat if you want safety!”

Britax’s additional safety features: (not found in other brands!)

There are a few additional safety features that you do not find in other car seats: First, the patented, energy-absorbing Versa-Tether has staged-release tether webbing, anchoring the top of the seat at two points to minimize forward movement, and for additional protection, the Harness Ultra Guard System (HUGS) reduces forward head movement.

britax boulevard safety ratingsSecondly, you can feel on your own that the straps of the Britax are superior to any other strap in the marketplace – the straps on all the other brands felt flimsy in comparison to the thick, durable, and wide webbing of the Britax straps. The additional width spreads impact and holds the child more securely in case of a crash, a worthwhile investment in your child’s safety.

Additionally, the Britax Marathon also has an additional feature called Side Impact Protection, which is a system composed of the rigid seat shell, the deep side walls minimize impact in case of a crash into the side of the vehicle- which is actually one of the most common types of crashes. (This is the main difference between the Britax Marathon and the similar Britax Boulevard; as the Boulevard car seat has extended head-wings which are called True Side Impact Protection.)

Britax Marathon Convertible Ease of installation:

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britax marathon rear view

In my humble opinion, many inferior car seat manuals ought to contain a warning not to use profanities within earshot of children while installing! Right off the bat, the Marathon scored points due to the use of actual photos in its manual, as opposed to the confusing line drawings that other brands show in their manuals!

Some car seats require brute strength and muscle to be installed correctly. A common tale of woe is that adults must literally sit on the car seat in order to push it as far back as necessary for proper installation. No small amount of cursing was heard when we had to switch other brands of car seats between vehicles – not fun! The Britax is a dream to install, and virtually all parents who started out with an inferior brand reported after purchasing the Britax that they wish they’d gotten a Britax from the get-go! Moms who have used multiple car seats were unanimous in their opinion that only a Britax did not budge a single inch once it was installed!

britax boulevard review

Note: Ease of installation is of paramount importance regarding SAFETY if you will switch the car seat between Mom/ Dad/ Grandma/ the sitter’s vehicles on a regular basis. (Otherwise, someone, at some point, won’t bother to install the car seat correctly when transitioning to different cars.)

Testimonial from a Dad: “My 16 month old daughter was riding in one of these when the truck she was in, a Dodge Ram, rolled over repeatedly at highway speed. My wife was cut and bruised and her mother suffered fractured vertebrae. My daughter literally was not scratched.”

Britax Marathon Car Seat Ease of Strap Adjustments:

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britax marathon convertible car seat

Parents found the straps simple to adjust with the lever at the center front which loosened and tightened the harness easily. This is a very beneficial feature if your child is sleeping, you can easily adjust the straps to loosen them and take your baby out without waking her up to bend her arms out of the straps. (Value of not awakening baby from her nap = priceless!)

Click here to check out daily 20%-60% discounts on Amazon for these car seats for today:

Sales are subject to change daily!

No “fishing” for the straps behind baby’s back!

Another handy feature only found in Britax car seats is the Velcro on the side of the straps, which keeps them out of the way while placing the child in the seat – a common occurrence in other brands is having to “fish out” the straps from under the child after he is sitting in the seat. This makes getting into the seat easier and faster. (Who wants to attempt buckling up a crying toddler while searching under his bottom for that elusive strap?!)

Adjusting the harness height: The Marathon 65 requires re-threading when your child grows taller and needs a higher shoulder harness slot. You’ll need to uninstall the car seat to access the back of it, and then re-thread the harness through the higher slot position. (Note that the updated Marathon 70 makes adjusting the harness strap much easier, they eliminated the need for re-threading and accessing the back of the seat in the Next Generation Britax Marathon 70 car seat.)

Comfort of the Britax Marathon Convertible Car Seat:

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britax marathon

When baby is comfy, everyone in the car is happy!

This is a large car seat, which gives your child plenty of room to feel comfortable rather than confined. The mattress-quality padding make this seat literally a relaxing recliner for your kid during car travels!

Many parents reported gratefully that car trips ceased to be a screaming nightmare once they switched their child from smaller seats to the Britax Marathon safety seat. After all, you wouldn’t want to feel confined in a tight space while traveling – neither does your kid!

Height matters – here’s why:

The height of this car seat is advantageous over other lower-sitting car seats since it allows your baby to see out the window which definitely minimizes crying and makes driving more pleasant. (You wouldn’t want to be stuck looking at a door and only seeing the sky out of the window, would you?!)

No more “head-flapping-like-a-dead-puppet”!

britax boulevard safety ratingsParents who used the Britax in the rear-facing position reported that this is the only seat where the baby’s head did not roll forward while she was sleeping – the Britax keeps your baby’s head secure against the seat. One other nice feature is the pads on the shoulder straps – many inferior car seats cause red marks on babies necks due to the friction with the rough straps. (I disliked that dead-puppet-flapping when my children’s heads rolled forward in other seats, although the kids do seem to have survived!.)

Real customer reviews from real parents regarding their Britax Marathon:

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britax marathon pros and cons

Testimonial from a dad of three: “Buy the Britax rather than trying to save money and buying another brand. Skip a dinner out if necessary; you won’t regret it! I gave all of our other car seats to Goodwill after buying the Britax.”

Over and over again, I came across blogs and forums where parents said that they wished they would have started out with the Britax Marathon rather than attempting to save money and buy an inferior brand. It is pricey, but it will last for years, so if you do the math, you are probably paying an extra $15 or $20 per year of use – which is less than one cent per day of superior comfort, ease of use, and safety!

Washing the seat cover:

britax boulevard review

Although the directions say to hand wash the car seat cover, many parents reported to having washed all parts of the car seat cover in the machine on the gentle cycle, and then having it look as good as new after multiple washings. Inferior brands tend to pill and get worn out after washing, which necessitates ordering a new car seat cover for about $50 every time your child throws up or has a leaky diaper, or just spills a yogurt all over the seat!

A few parents mentioned that it was a bit tricky to remove the seat cover for washing, but once you figured it out, you got used to the system of unhooking little tabs. Although Britax recommends washing the cover by hand and air drying, many parents reported that they did machine-dry the cover and it looked as good as new. (Definitely try the machine-drying at your own risk, and use the lowest possible setting on your dryer!)

Any complaints?

One complaint some parents had was that as their children grew taller, they tended to outgrow the Marathon due to their height before the 65 lb weight limit – it depends on your child’s height and weight proportion. If you want to be sure that your child will use this car seat for many years and do not have a younger child to pass it on to, you can check out the Britax Boulevard, which has a roomier seating area for older children.

Another con was that the darker fabrics on this seat do tend to heat up in the summer heat. Customers from Arizona reported that the denim fabric stayed the coolest when the car was parked in a sunny spot. (The popular Onyx fabric is a velour, so it definitely heats up in the summertime!)

britax boulevard safety ratingsThe other disappointment some parents expressed was that the size of the Marathon did not allow for a third passenger to sit in the passenger row when two Marathons were buckled into that row. It seems that this is the case with all large car seats — if you intend to fit a third passenger between two car seats, you definitely want to search for smaller car seat. (One parent reported being able to fit two Marathons plus a thin grade-school child in the passenger row of a Honda Odyssey.) On the other hand, the bulk of the seat provides additional safety and would spread impact in case of a crash.

Keep in mind that there were just a few complaints among the 400+ Amazon reviews for the Britax Marathon; 94% of people rated this seat with 4 or 5 stars!

Customer Review: “Before purchasing this seat, we bought several cheaper seats (Graco, Evenflo etc.) All of them went back to the store within 3 days. They were difficult to get a super tight installation, the harness straps easily got twisted and sometimes didn’t tighten evenly, and my son just didn’t look as comfortable in these seats. Finally, due to the great reviews we splurged on a Marathon. We should’ve just started there in the first place. We are a young family on a budget, but I would buy this again in a heartbeat for safety and ease of use. It is well worth the extra money for a fantastic, easy to use, and safe product that you will use DAILY for several YEARS! We recently purchased a second Britax for our new baby, can’t wait to use it!”

Where can I get the best price for the Britax Marathon?

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britax boulevard review beat local stores and other websites by $20 – $80 on a regular basis. However, because they are generally the cheapest, it often sells out, so if you see it in stock on Amazon grab it while it’s still available!

Note: Sometimes, when you check out this car seat on Amazon, you will not see a price, rather, Amazon will say, “Check price in cart”. So you add the item to your cart, and then you are shown the price. While this may be inconvenient, it saves you a lot of money: The manufacturer does not allow the product to be sold for less than a certain amount of money publicly. Since Amazon sells this car seat for less than the manufacturer’s allowed price, they cannot display the price until you have added the item to your shopping cart. So, that extra click of your mouse will save you a nice amount of dollars over buying the car seat in a local store or at any other website.
britax marathon 65 picture

Click here to check out daily 20%-60% discounts on Amazon for these car seats for today:

Sales are subject to change daily!


13 Responses to “Britax Marathon 65 Convertible Car Seat Reviews”
  1. Jane says:

    Great and well researched article. It really helped me a lot in choosing a car seat for my baby boy. I would definitely suggest you site to my friends. Your article has a lot of pictures that are really helpful. Thanks for this great read!!

  2. You’re welcome, Jane! Feel free to post any questions that come to mind, and I’ll do my best to help:)

  3. Holly says:

    One other money saving tip – we picked up an extra Marathon for our second care for $155 at Babies R’ Us because they were switching out the display model for a new one. It was only manufactured six months before we bought it and we saved well over $100!

    • Great idea, Holly! I’d suggest calling ahead to find out if there are any floor samples or discontinued models on sale before you bother driving out to the store. Employees at baby stores are generally very helpful and friendly.

      Quick warning about baby stores: do not assume that just because someone works at a baby store, he/she has any special knowledge about car seats. If you have technical questions about installing or using a car seat, find a certified car seat technician here:

      Also, be aware that seats do expire in 6 or 8 years (each has its own expiration date), and if you are buying a seat that is already a year old, you will be losing out on a year of usage.

      • Emma says:

        Hi Ellen,

        I’m looking for a child seat fron an eight year old that has wings, head support etc as my child is growing out of his. We have a Britax which he loves, and although it will go taller for him, the width of the wings are now starting to cause him to round his shoulders to sit all the way back into the seat, and this can’t be good for his posture.

        Can you recommend a brand that are wider at teh shoulders but still have the side supports for extra safety?

        • Hi Emma,
          At 8 years old, I would start transitioning your child to a highback booster if he no longer fits comfortably in his convertible car seat. At this age, there are no studies to show that it’s safer to be harnessed in a forward facing car seat than to be sitting properly in a belt positioning booster. He likely will outgrow any other car seat soon — for example, the True Fit, while having a slightly wider shell by the shoulders doesn’t last as long for height — and he should be mature enough to sit in a highback booster.
          If you’re comfortable with this recommendation, I’d suggest looking at this Sunshine Kids Monterey Booster. The Sunshine Monterey Booster has an incredible adjusting feature: Expandable width-seat back adjusts to fit shoulders up to 20″ and adjustable height-11 position headrest, adjusts up to 6.5″ with one hand. It still has Side Impact Protection (SIP), and overall is an EXCELLENT booster for your growing boy. has it available with free return shipping, so you aren’t risking much by trying it and returning it if it doesn’t work for you.
          Alternatively, the Chicco Keyfit Strada is a booster that has SIP also allows for adjusting the shoulder wings, but it only allows for a child up to 57″ instead of the 63″ the Monterey provides for.
          If you’re willing to splurge on another seat that will allow your son to remain harnessed for longer and then switch to highback booster mode, Britax makes the Frontier 85 SICT which will allow him to be harnessed till 85 lbs. The wings appear to be wide from what I see, but I have never seen specs on the actual dimensions…but again, with free returns allowed by Amazon, you can definitely try this option and see if it works for your son.
          If there are any other questions you have, I’d be happy to answer. :)

  4. Noah's Mom says:

    My son is almost 5 yrs old, 40 lbs and about to grow out of our Britax Marathon height wise. I really hesitate to leave it because it saved his life when he was 2 yrs old. We were hit in the passenger side by an 18 wheel tractor trailer going 30 miles an hour. If not for this car seat, it would have been much worse than the 3 surgeries he endured. Can not say enough good about Britax. Parents, don’t be too quick to jump to a backless booster for “convenience” because you never know when your child will need more. You’ll be glad you did.

    • Hi Noah’s Mom,

      So glad that he was okay in the end. Life can be so scary.

      Are you going to get a Britax Frontier when he is too tall for the Marathon? The other one I’d recommend is the Sunshine Kids Radian- it has a very tall shell.

  5. Allie says:

    Hello, I have had a Britax Marathon 65 (Classic) for a year, and have loved it. I just bought the Marathon 70 (next generation) for my husband’s car, and am unimpressed by how flimsy the seat seams compared to my older model. Has anyone else noticed this? Does this seem to be a major safety concern? Any comments, suggestions are welcome. Thanks!

  6. Holly says:

    I have been researching for week’s now and kept wondering if the britax was worth the money. Of course you cant put a price on your child’s safety but I didn’t know exactly what the difference’s were that made it so much safer. This sum’s up all the difference’s for me. I will be purchasing a britax. Thanks so much!

  7. Eva says:

    Target has the Marathon 65 classic on sale and the lowest price difference between this old model to the newer Marathon 70 is about $70. I notice the Marathon 70 has a head cushion while the classic does not. What’s the difference between these 2? Any safety difference?

    • Ellen says:

      In terms of safety, the Marathon 70 has the new safe cell technology which they say does make the seat safer. It’s very safe without it though, as well.
      The 70 is more economic on space: it has a shorter shell, takes up less space from front to back (it installs more upright), and sits lower in the car.
      The main advantage of the 70 is the harness adjuster — it’s quite improved from the one on the classic Marathon 65. There is no rethreading, and you have more options as to where the harness should be situated.
      Is it worth the $70 difference? Only you can make that call.

      I hope that helps!

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