This is not surprisingly the most common question by parents. We all want the best for our precious little kids. There is no good answer to this question and buying a seat which has placed “best in test” might not give any additional safety. Lets start by saying rear facing is the absolute safest. Regardless of seat, don’t turn your child forward facing until you have reached the limits of your seat by height or weight.
Truth is that most well known rear facing car seats offer equal safety. It’s rear facing which is the huge advantage, not car seat model. Testing done by car seat manufacturers are never shown in public. All tests are also different. A different sled might be used, different speeds, different install, etc. The Swedish seats which we carry in our online store all offer equal rear facing safety.
Safety in a collision might vary depending on install and type of vehicle. Those are factors which are always going to be there but knowing this might perhaps encourage parents to read the manual a little extra.