•Harness straps don't twist.
•Built-in lock-offs for seat belt installations.
•Push-button LATCh connectors.
•Rear-facing and forward-facing tether.
Cons
•Price. Expect to pay $200-$250 for this car seat.
•This car seat is heavy!
•Not a good fit for most newborns.
Description
•Britax Marathon is a convertible car seat with 5-point harness for babies 5 to 65 pounds.
•May be installed rear-facing to 35 pounds and forward facing to 65 pounds and 49 inches tall.
•Versa-Tether allows top car seat tether to be used rear-facing and forward-facing.
•Removable seat cover is stain-resistant and available in many colors and patterns.
Guide Review - Britax Marathon Convertible Car Seat Review
I didn't know it was possible to fall in love with a car seat! I had heard other parents rave about their Britax seats for years before I splurged and got one for my daughter. She immediately took to the new seat, as well, even wanting to sleep inside the Marathon the first night we had it.
One of the nicest features of the Britax Marathon car seat is the built-in lock-off clips that keep the car seat installed tightly when using traditional seat belt routing. Just slide the seat belt through the lock-off, tighten, and close the lock-off. If you're installing the Marathon car seat with LATCh, the trickest part is figuring out whether the LATCh belts are set for rear-facing or forward-facing. They come set up for rear-facing, and you'll have to slide them around on their metal bar to switch positions. Aside from that, LATCh installation is incredibly easy in every vehicle I've ever installed a Marathon in. The push-button LATCh connectors are very nice.
Britax has also made it very easy to secure babies in the Marathon. The harness straps adjust quickly and effortlessly, though some parents complain that their child can figure out easily how to loosen the harness. The harness height is simple to change, but you must uninstall the car seat to adjust harness height in the forward-facing position. The thick harness straps on the Marathon car seat do not twist like those on cheaper car seats.
The shell of the Britax Marathon car seat is quite tall, and the top harness slots are at about 17 inches. Most children will outgrow this car seat by height before they reach the 65 lb weight limit. My own daughter was able to ride in the Marathon until she was about 6 years old, when her shoulders finally went over the top harness slots. On the other end of the scale, the Marathon is generally not a good choice for newborns. It doesn't come with a newborn pad, and the bottom harness slots, at around 10 inches, are not as low as those of most infant car seats. Most newborns won't fit well in a Marathon unless they're very big at birth.
Marathon is a large car seat, and some small car owners may have trouble with proper installations, particularly rear-facing, so check the fit before purchasing. It appears that Britax has redesigned the Marathon car seat base to better accommodate small cars, though. The base makes for easy recline adjustments when rear-facing, too, by simply pulling a handle. Plush covers and thick padding provides a comfy ride for baby, and the covers are available in many patterns to suit any taste.