Britax Marathon 70 Convertible Car Seat, Azalea

Britax Marathon 70 Convertible Car Seat, Azalea

The BRITAX MARATHON 70 convertible car seat is designed for children rear facing from 5 to 40 pounds and forward facing from 1 year and 20 pounds up to 70 pounds. The MARATHON 70 achieves revolutionary head safety through the use of BRITAX SafeCell Technology, integrated steel bars, and Versa-Tether that work together to minimize head excursion and reduce the risk of head injury during a frontal impact. The MARATHON 70 also incorporates BRITAX Side Impact Protection, offers a no-rethread and quick-adjust five-point harness, multiple buckle and recline adjustments, and an easy access cover and access to belt paths from the front of the seat. A head and body pillow is provided for comfort.

Main features

  • Safecell technology features safecells designed to compress in a crash, significantly lowering the center of gravity and counteracting the forward rotation of the child seat which normally propels the child toward the front seat
  • Integrated steel bars strengthen the connection to the vehicle and reduce forward flexing of the child seat during a crash
  • Energy-absorbing versa-tether features a staged-release tether webbing to slow the forward movement, reducing the crash forces reaching the child, and a two-point attachment to minimize forward rotation while anchoring the top of the child seat
  • Side Impact Protection comprised of deep side walls lined with energy-absorbing EPP foam distributes crash forces, shields from vehicle intrusion, and contains the head, neck and body
  • Tangle-Free, Five-point harness distributes crash forces across the strongest parts of the body and provides a secure fit

Verified reviews


High marks for crash safety, low marks for day to day functionality

There are days when I’m sure all the design engineers working behind the scenes on this item care about is increasing how many times a car can rollover and this car seat still be structurally intact.Why? Because I commute on a curvy road. Every morning, I bundle my kid into this car seat (which is still rear-facing). When I enter a curve, she is plunged into deep shade, and when I exit the curve, the sun’s rays slap her in the face coming through the rear window. Yes, she is wearing a sunhat, but it isn’t a pioneer pokebonnet. Poor thing has a difficult time sleeping and no wonder her eyes have to adjust to all the dramatic changes in light level every 30 seconds. Does Britax make some kind of shade attachment for this car seat? Not that I have found. What they are about to release are two translucent gray sunshade panels that stick to the two rear windows. That will TOTALLY not help with the sun coming in through the rear window in backwards facing configuration. Now the recommendations are to leave them backwards-facing as long as possible, so I’m reluctant to flip her around just because she still thinks sunglasses are for chewing on.As another reviewer mentioned, there are two velcro tabs on the upholstered part of the seat that look as though they are designed to hold the shoulder straps out of the way. Do they? Nope. They are positioned far too low, and are so small that the friction of sliding a toddler past them often dislodges the strap. I have to dig the straps out from underneath her tush, which she does not appreciate. One of tabs came un-stitched and was dangling by a couple of threads. I believe they call that a choking hazard. These tabs provide the ILLUSION of helping to keep the straps out of the way while actually doing no such thing. In addition, they have that single line of cheap stitching all the way around that toddler fingers can TOTALLY do a number on.Finally, if you intend to take this puppy on an airplane, either shell out the $60 for the Britax cart that allows you to wheel this granitic behemoth of a car seat around the airport, OR have your chiropractic appointment all set up for when you get back. It does say it is FAA approved in tiny print on the label, BUT the generous cut of this car seat means that we could not fit it into her (not so generous) coach airplane seat rear-facing, and that forward-facing, she could totally kick the bejesus out of the seat in front of her. And she was under a year old, maybe 27 inches long.If you are going to make a sizable investment, consider the other premium brands. Not only did Britax recently get dinged for using a lot of rather toxic flame retardants, but the day to day inconveniences are something of a grinding irritant. If you are the kind of person who rolls your vehicle frequently, then I guess the small things don’t matter so much. Now I’m off to Etsy to find an artisan who makes pokebonnets.

Shari Everglades City, FL

Awesome carseat design, but very toxic!

Britax carseats are very toxic. They have some of the highest levels of fire retardants, lead, bpa, etc. I learned about this after using it for some time. If you buy one, wash the entire cover with warm water and vinegar. Also, buy a few months before use and leave in the garage to off gas. It is pretty pathetic that we have to take it upon ourselves to minimize cancer causing toxins in our children’s products. How do these companies even sleep at night and why are these horrible chemicals even legal??? So frustrating!!

Jeannette Goodson, MO

Fits fine RF in small car

I just had this car seat installed RF in my VW GTI and it fits perfectly fine with room for someone to sit in the front seat. I had looked all over the internet for this info but could not find it so I was concerned I would have to return the seat for lack of space. Pleasantly surprised I didn’t have to!. Also, I had it professionally installed but I was there as it was done and it looked like a breeze (RF with the latch system).

Trina Carbondale, PA

Excellent Carseat!

i tend to research my baby products extensively, and this carseat was hands down the most highly recommended one on the internet from multiple reliable sources. we love this carseat, it was very easy to setup and install in our 2010 nissan altima sedan. the construction is very solid, and the operation of all of the harnesses i smooth and easy to use. our 1 year old son seems to be very comfortable in it. the safety ratings on this carseat are very high, so God forbid we ever put that to the test i am very confident in this carseats safety features. the height adjustment of the shoulder straps is also a nice feature, as you do not have to remove anything or take off any buckles, just squeeze a lever and slide it to the desired height. tightening and releasing the harness is effortless. highly recommended! if we ever come across any issues with this seat i will update this review, but as of now its GREAT!

Carey Elba, AL

Love, love, love Britax!

I love the safety features that Britax offers with their seats. I ordered this seat for my daughter when she was 10 months old. It works great as rear or forward facing. Just be careful when washing the seat cover. It is hand wash ONLY! I made the mistake of putting it in the washing machine and the seams started to fall apart 🙁

Rosalinda Salvo, NC

Sits high and material is great

This is really easy to install. It sits high up so my daughter likes being in it. The material doesn’t keep her hot even in hot and humid weather of the Philippines. We have installed it in different cars and it really has not taken up a lot of space. 2 adults can still sit beside her. We are really happy with our purchase and will get another one for the next baby!

Lea Black Rock, AR


I recommend this car seat to EVERYONE!!! I’ve even talked a few friends into buying this car seat. I LOVE how long you can stay rear facing, which is VERY important. I would never buy a car seat from a different company and I will be purchasing another with future children.

Fannie Glen Arm, MD

Love this Carseat

We love this carseat so much we bought four of them (myself, my husband, my mom, and my MIL)! Love the harness straps and my son rides comfortably and I feel he is safe.

Emily Black River Falls, WI

Doesnt Move an INCH

I love this car seat. I have a britax boulavard 70 CS in my car, and we always loved it. In my husbands car, we had a eddie bauer that someone gave us. Well the eddie bauer was just awful, you cant get it tight, the straps always get twisted. What junk. Now my son is almost 9 months old and I just couldnt take it anymore… we HAD to get a better car seat for him. We got an evenflo triumph, and my son is pretty tall so the harness slots didnt fit him right, we returned it before it even made its way to the car. Anyways we decided we love the Britax in my car so much that we’d just get the same, but maybe a lower model. We ended up getting the Marathon Classic 65 at a local store ON SALE so it was only $160.00 and just like the other Britax we LOVE it. It is sooo easy to install rear facing, very comfy, and most importantly it does not move one single inch in any direction. I just cant rave enough about Britax. I will never ever get anything else… they are sooo worth the extra money. Just keep your eyes open for a sale and its not even that bad. Another problem I had with the evenflo, and the eddie bauer is that when you tighten the staps one shoulder gets tight and the other doesnt. Not with the Britax. Also, with the Eddie Bauer, we could NOT tighten the straps at all when rear facing because it was blocked by the back part of the back seat. We had to basicly pre-tighten the straps before we installed it and then just buckle him in. We both have very compact cars (mazda 3 and saturn ion) and the Britax fits in them both behind the passanger seat nicely.

Ester Hillpoint, WI

Good Car Seat

This car seat is definitely on the bigger side but I feel like it’s really good quality and reasonably easy to get my baby in and out.

Lois Beemer, NE

My Second One!

This is the second car seat that I bought from Britax, same model, just a different color. Now I have one for each car. I like how sturdy it is and how you can adjust as the child grows.

Josephine Preston, KY

Perfect for Transitioning from Infant Car Seat

I bought 3 different car-seats for my daughter & family, one for use in each of our cars. (They are the Britax Marathon, Britax Frontier, & the Recaro Prosport). All seem equally heavy & bulky, though the Marathon is geared more toward a younger & smaller child. All seem equally comfortable but the Marathon is probably best in transitioning out of the infant carrier (we previously had the Graco Key Fit 30 & loved it!). We got the Marathon at about 12 mo. Then we got the Frontier & the Recaro when my Grandson was about 18 mo, and he loves all of of them equally. They are very similar in style & I can’t say one is really better than the other. They are all bulky & rather difficult to manage & transition out of the cars, so we just leave them in place in the perspective cars & travel with him primarily in those 3 cars where the Marathon, Frontier, & Recaro are placed. We have never had any of the 3 carseats rear-facing, so I can’t comment on that. Of course our little guy remained rear facing in the Graco Key Fit until he outgrew it. He is 27 months now, & still fits in the Marathon but he especially likes the Frontier & Recaro because he can sit more upright & see out better. He has no problems napping in any of the 3 carseats.

Cherie Davy, WV

love the latch system

We kept our little guy in his Chicco until the last possible moment. It was just so easy to install and change from one car to the next with the latch system. Our next carseat not only had a latch system that was difficult to use, but in the backward-facing position it leaned so far back that the front seat had to be pushed all the way against the dashboard. Not very safe, to say the least.We decided to get the britax marathon after reading reviews that it fit well in the Honda Accord, which we have. I also made sure it had an easy latch system, since he’ll be sitting backward-facing at least another year, and we have two cars that we are constantly moving his car seat in and out of.The britax works great. It was so easy to install right out of the box. My only two complaints are that it creates a narrow space between the door jam and the back of the carseat to get him into the seat, so the first time I used it I accidentally bumped his head on the door. Also, the silicon-like things encasing the chest band are a little unwieldy when you fasten them.Besides those two gripes, I love this carseat. It feels very secure and snug, and it still leaves lots of room in the front passenger’s seat.

Camilla Capistrano Beach, CA

Great for a second seat

I have the Britax Advocate in my car and bought this as a second seat for my husbands car. So far I love it! You can tell it is a lot cheaper made than my advocate. The buckle is smaller, the rubber parts are thinner, and the sides are more flimsy as well. All overall for the money I would do it again as a second seat. If you are looking for the seat that your child is going to be in the most I would spend the extra money and get the Advocate. The gray material is a velour and the pink print is more of a cotton blend that could snag easier than the zebra print on my advocate. btw-this is in a 2002 Toyota highlander rear facing, all the way reclined and still has plenty of room for the driver’s seat to be comfortable to drive and then some.

Myrtle Hermitage, TN

Seems sketchy for a newborn

We decided when I was still pregnant to get just a convertible seat and not an infant car seat. This seat is rated down to 5 lbs, so we figured it would be just as good as (if not better than) a separate infant car seat/ carrier. This review is applicable to that decision- and may well reflect on all Convertible vs Infant seat decisions, rather that being a comparison between this and other convertible seats.When we were ready to leave the hospital, the staff told us to bring up our seat to show them that we had one and to carry the little one down in. We told them we couldn’t- we had it installed correctly and didn’t want to undo that. They were ok with our response and never checked to make sure we had a seat.When we put our newborn (born at 7lbs 5.5oz- and proportionally tall in the torso, short in the legs) in the seat, the plastic chest guards stuck up so high, they poked her under the chin- it looked like she was being choked.And the shoulder straps, which are encased in a velvet-type material, didn’t sit over her shoulders at all. This really made (and still makes) me nervous- it’s clearly a safety issue, and I don’t know how the seat managed to pass testing for down to 5 lb babies.In the first few weeks, she was very unhappy every time she was placed in her car seat- crying extensively starting when we clicked the lower latches in place. From this, I assume it was uncomfortable for her.We purchased and installed the infant positioner from Britax, expecting this to fix the issue, but it didn’t help, and it made it hard to click and unclick the lower latch (especially when she was in cloth diapers, but also when she was in disposables).She is now three months old, and still the shoulder straps don’t quite sit over her shoulders, but slip off horizontally, even though we keep the chest latch positioned where the manufacturer recommends it.We stopped using the infant positioner several weeks ago, since she outgrew it, and that did make clicking the lower latches somewhat easier.Last week, we flew to another state so the grandparents could meet their new granddaughter. This seat is extremely bulky and heavy, not to mention difficult to install. We purchased the Britax travel bag to put this in. It is convenient, since it rolls, but the seat does not fit in the security x-ray machines, so the TSA had to check the carseat by hand- in one of the two airport securities, they made us take it out of the bag. When you are already dealing with the normal security rigamarol, plus carrying your infant through the scanner, that is one annoying, and not so easy while caring for an infant in one arm, extra step. Then getting it installed correctly in the rental car on the other end was also complex- not to be done one handed- it would be very difficult for one adult travel with this and an infant alone! You’d have to find a safe place to lay the infant down while you installed it.Overall, I expect this seat to be a good one as she grows bigger, and it is not as unattractive as most I have seen, but I have serious concerns on the safety for smaller infants. I suspect it was a mistake believing the rating down to 5 lbs, and if I had it to do over again, I’d spend the extra $$$ on an infant car seat for the first few months.

Ella Regina, KY

What a Value!

This is a $299.00 car seat for $199.00!!!!!!!!!!!!! And worth every penny!!! Easy to install, cute, comfortable, and one of the safest on the market! And it grows with your baby! All these reviews about the toxic chemicals from fire proofing need to do more research. Yes, the CHEST AND CROTCH CLIP are highly coated in fire proof chemicals. To affect your child in any way your kid would need to physically eat both clips AND the fact they ate an object would be more damaging then anything. Do you know why it is coated in these chemicals? So if your car sets on fire THE CLIPS DON’T MELT AND MALFUNCTION LEAVING YOUR CHILD TRAPPED IN A CAR SEAT IN A BURNING CAR!!!!!!!!!!!!!!!I HATE the fact people are writing reviews scaring people from buying this seat! It is one of the safest seats! Do your homework when researching don’t just Google everything!

Beatrice Slatyfork, WV

Easy to use, great features

I have been using the Britax Marathon 70 since my son was born nearly two years ago. We skipped the infant seat and went straight to a convertible (with the help of the Britax foam infant insert). This seat is installed in my 2002 Honda Accord with LATCH rear-facing, tethered to the front passenger seat. It is a rock-solid install, and very easy thanks to the premium LATCH connectors (so much better than the hooks used by other seats). The no rethread harness is nice for on the fly adjustments – nothing worse than putting your kid in the car and realizing the harness isn’t at the right height. The harness straps are nice and thick and I’ve never had issues with them twisting. The velcro tabs on the side of the seat keep the straps out of the way when getting the child in and out of the seat. I wish the crotch buckle had a similar feature because otherwise it does get buried, but I have figured a way to keep it accessible.My one complaint with Britax seats is that they have shorter shells compared to other seats on the market. If you are like me and interested in rear-facing beyond the age of two, Britax seats are a gamble. My son appears to be below average height, so at almost two he still has a bit of room before he’ll outgrow it rear-facing. The seats are so easy to install and adjust, very comfortable, and very expensive – it would be nice if parents could buy them and have confidence that they could be used as long as say, the Chicco Nextfit or the Graco Size4Me70/My Size 70/Headwise70 (et al.).

Kaitlyn Harman, WV

Great car seat, worth the price

Upgraded to this car seat from a Graco infant carrier. (Graco Snugride 35 Infant Car Seat, Rittenhouse ). Our 1 year old (31″, 24 lbs.) is sitting rear facing in a Nissan Sentra. Car seat is secured using the LATCH system, and the teather strap is connected to the frame of the driver’s seat in the car. Setup and install was a breeze. Be sure to take advantage of the videos on the Britax website for install help – great resource. The owners manual does a good job of telling you all you need to know, but if you’re a visual person (I am!) the videos are great.We were hesitant about spending this kind of money on a car seat, but the safety features are outstanding and we know we’ll get at least 2 years out of this seat. When you add it all up the price is well worth what you receive.

Elma Sasser, GA

Love This Car Seat!

After lots of talks with friends & doing research online, I decided this car seat would be best for our 7 month old daughter. She seems to be very comfortable in the seat & the integrated steel bars make it seem like a really safe/durable seat. We opted to not get a car seat with the extra side protection cushion for a few reasons. First, it has not been proven that it actually does any extra good in crashes. Secondly, we live in Phoenix, Arizona and it gets really hot here. Our daughter gets overly heated easily as it is & having this extra stuff around her head would just make her hotter. And thirdly, our daughter really enjoys looking around, especially out the side back windows. These additional cushions block the peripheral view pretty much entirely. So a rear facing child who is unable to look out the side windows sounds like a recipe for boredom & lots of crying in the car to me. I know I would be bored out of my mind if all I could look at was the back of a seat & nothing else. I really like the Azalea design as well. It’s feminine, pretty, & doesn’t absorb a lot of heat like darker colors do. I also like that the straps rarely get twisted. I loved our Graco Snugride 35 seat, but I battled those straps on a regular basis! I highly recommend this car seat.

Fern Mars Hill, ME

Worth the money!

Easy to install even in the middle seat of our four-door truck. Sturdy, easy to adjust. Only complaints are in regards to the placement of the velcro to hold the straps open and gray protective straps are bulky.

Natasha Needham Heights, MA

Britax are the best!

Britax has outdone themselves with the Marathon 70.We’ve owned 4 of the original Marathons (now called ‘Classic’ model). One of them was over 3 years old and started having trouble with the crotch strap latch not latching properly, thus making the car seat unusable. Even though the original warranty is only a year, Britax swapped out our Marathon Classic with a Marathon 70 – shipped to us 2nd Day Air, at no cost to us, whatsoever. They even let us pick the fabric style. Needless to say, I’m impressed with their customer service and response.I love the Marathon 70. My favorite new feature is that ability to adjust the shoulder harness height without having to remove the seat from the car.These car seats are top of the line, ultra padded, and safe as can be.Yes, they are expensive, but if you ever are in an accident, you will never regret the money you spent. What’s an extra $100 to have your child walk away unharmed from a big accident?

Antoinette Muskego, WI

Best car seat out there!

I love this car seat so much I have one for my 24 month old and another for my 12 month old. I love that you can extend rear face (five times safer than forward facing) which we plan to do for as long as possible with both kids. The seat fits perfectly in my Prius, though I did have to use a rolled up towel under the base to get the angle just right.

Felecia Donnelly, ID

Great seat, but not my favorite

We have two convertible seats, this one and a Diono R120. They are both great seats but this one has a couple of drawbacks compared to the R120.Both seats have rear facing top tether which was important to us and both seem like high quality seats.My husband installed both seats and he found the installation of this one very annoying. I was surprised by this because I had heard so much about how easy Britax seats are to install. We both have a hard time getting the baby buckled in properly and the straps tightened properly. It’s just a lot easier to position him and get everything adjusted in the R120.Also this seat is quite wide. It essentially renders the entire backseat useless for passengers (we have it in the middle.)This is a great seat but for me personally I won’t but it again if I have a car that can handle the height of the Diono.

Ashleigh Kelso, WA

What you’d expect from Britax

This is a quality and safe carseat. We’ve used it for two years and it shows very little wear. After washing it once, the cover still looks great! We would buy it again… in fact, we did for our second child!

Ginger Noble, OK

No more tears in the car!

My 10 month old outgrew her infant car seat and we did some research- everyone recommended a Britax, as did consumer reports. We’ve endured 10 months of crying and screaming in the car and figured she was car sick or something. Well, we’ve had the Britax for a month (in the super cute cowmooflage!) and my little girl hasn’t cried or fussed once! On the contrary, she seems quite content and has even fallen asleep in it (something that she would never do without lots of crying first). It’s a snug fit in our tiny Honda Fit, but it works. I am so happy my little one seems so comfortable in it, and of course, that it is so highly rated for safety.

Tameka Fort Irwin, CA

Great, great, great!

Pricey, yes. Heavy, yes. But this is seriously the best you can get. Comfy, reclining, front and rear facing, straps never get tangled, wide range of height and weight, cute fabrics, and high quality. The rubber base really sticks to leather or fabric cars without damage, but without slippage either. The ONLY reason I gave this 4 stars is that I wish it was cheaper so that I could buy 2 for both my cars and it doesn’t have a cupholder. Switching back and forth is a pain, but worth it in my opinion, especially since the installation of this car seat is easier than most. The most important thing is that it is safe. And that is why you buy a car seat, for safety.

Dorothy Corinne, WV

Safe and comfortable

This car seat is clearly safe, which is the most important thing. It appeared to be comfortable for my child. What i like most about this car seat is the latches in the front are very easy for an adult to snap and not so easy for a child to unsnap. My child has used two other car seats (both Gracos) and at a young age (less than 1 yrs old) she was able to unlatch the top part of the harness (as it did not take much pressure to unlactch it).It is also easy to install so if you have to move the car seat into another car you will not spend much time adjusting and tightening.The reason I am givign this 4 stars is because after removing the cover to wash it I noticed how cheap the cushionng material is (although it was clearly comfortable for my child). Also, once the cover was removed I was never able to get the cover to fit back on the car seat the same. It constantly came loose or came off. When the car seat cover becomes loose the frame of the car seat became exposed and there is a hole between the back of the carseat frame and the side of the careseat. My child was able to stick her arm in that little hole and got her arm stuck. I had to pull the car over and remove her little arm from the hole.

Kerry Semora, NC

If you can, spend the money

Bought the Graco Alano "flip it" travel system which came with the Graco Snug Fit Classic Car Seat. That was one of the worst purchases I’ve made while prepping for the first baby. The second worst would be a diaper wipe warmer. What a waste of money.My daughter would cry her heart out while riding in the classic snug fit. I purchased the Marathon 70 and the nightmare drives ended. Upon inspection I realized the material used on the Marathon 70 is of better quality and breathable. The Graco is lined with this cheap non-breathable polyester fabric material. So many times would I find her sweaty after a nap even if the weather was pleasant. On the Marathon 70, the car seat is lined with two different dense foam where her little tush sits. One hard foam for the structure of the car seat the other reminds me of foam used for a couch resulting in a comfy ride. The Graco, has none just hard plastic. Hm, maybe that’s why the whining would start after sitting there for 30 mins.It’s been a year since I’ve purchased the Marathon 70 and my daughter loves her car seat. She happy climbs in. I bought the cup holder as well about a couple months after. I got tired of my daughter dropping her sippy cup while on the road. I’ve used the cup holder for her drinks, snacks, even to hold her pacifier or her favorite little toy.The fabric is easy to remove and clean in the wash. I usually spray the rest of the car seat with a hose to remove all the gold fish and spilled juice stains. This seat has also been awesome on family road trips. Best purchase I’ve made. I’m gonna to have to buy another when the second one pops out in a month.

Britney New Cambria, MO

Cute and easy to install

We used the latch system on our maxi-Cosi mico infant car seat so we were familiar with the installation mechanism in the rear facing position. The straps adjust easily and the seat reclines for a younger babies comfort and safety. We did go to the local police to have it installed the first time just to be safe. I will do the same when I have to switch to forward facing. so far, very happy with this purchase.

Delores Vesta, VA

Love this carseat!

Perfect carseats! Easy to install, a dream to use, and my daughter seems very comfy in it. We’re using it rear facing for now and it seems to recline just enough… There’s also a position for the seat to sit more upright in the forward facing position for the future. Straps never tangle, belly padding makes for extra comfortable naps, cute pattern… Need I go on? A+++ carseat. You won’t be disappointed!

Jeannie Westhoff, TX