Britax Marathon Car Seat Expiring?

Unfortunately, I think it's true. Especially if it has actually been used for 6 years, not just sitting in your basement for 3 out of the 6. If you do decide to buy a new one, the Frontier is great and has a higher weight limit and looks more like a big kid booster. They are both the same price too, $279. It can only be forward facing and has a weight and height minimum. I don't remember what it is but we put my daughter in it a litle over two and she was big enough for it.

I am so glad you asked this question. We have the same seat and have never heard of this but I will be interested to see your responses! Sorry I could not be helpful.

I just bought the Britax Marathon about one month ago for my 9 month old daughter and am hoping to use it for our future children as well. I do think; however, that we should stop using the carseat after the manufacturer's recommended "expiration date". This is just my opinion, because of course, maybe the carseat would function just as well after the expiration date, but maybe it wouldn't. If the manufacturer can't guarantee it's safety, I wouldn't be comfortable using it. I can see how the plastic might be less effective/sturdy after 6 years in the car and being exposed to hot and freezing temperatures on and off again and again each season. I believe that I read somewhere that over time and with extreme temperature fluctuations, tiny micro-cracks can form in the plastic.

Yes, carseats do have a 6 year expiration date. The plastic is subjected to wear and tear and heat and cold....I would not use it for my children past the expiration date. If you do get a new seat (and I def would....I have a 1 year old using his brother's old Britax Marathon as well so I know what you mean) there is a FANTASTIC seat out there now called the Graco Matrix that will keep your 2 year old harnessed to 65 lbs and then also converts to a a high back booster when you think your child is ready. It is 150-179, so alot cheaper than the Britax. And although Britax does harness to 65 lbs, children are more likely to outgrow it by height prior to that date, where as the Matrix has been designed to fit taller children.

After some more responses come in I may be convinced differently but as of right now, my answer would be that I would continue to use the carseat. I just don't see the problem with it. I wouldn't have even known that carseats had an expiration date...