quote Hey Moe. The way I see it, the value of your head cannot be expressed in monetary terms. This is my newest helmet. I got it for $49.99 from JCWhitney, with free shipping. It is a ZIR, which is DOT approved only. I have a total of 6 helmets, 4 of which are both DOT and Snell approved. I did some research on helmet ratings, after someone on here made a post about it, including a link to a rather lengthy motorcycle magazine article about it, including a conversation with Dr. Harry Hurt himself. According to professor Hurt, DOT helmets are actually safer in the type of accidents most riders have, than Snell rated helmets. Considering his reputation, I’ll take his advice over anyone elses anytime. Not only that, but DOT only helmets are a lot cheaper than Snell helmets. And this particular model did better in their tests than some $300+ helmets. As for those Chinese things, I won’t even go there. Peace. Jerry. /quote
Keep in mind DOT helmet standards are hardly policed and rely on the manufacturers themselves to adhere to the standards. Snell is an independent third party certification and helmets are tested more frequently. Snell has a lower G force threshold for peak forces and has requirements for multiple im[acts, but does not address duration of forces.
A lot of people claim a Snell helmet is more expensive because of the certification, but I believe a lot of the companies that use Snell tend to push the envelope more on making their helmet lighter, more ventilated, or easier to use and rely on the Snell sticker to add peace of mind to the customer.
This doesn't mean a DOT helmet is not as good, they in fact can be better or worse, but there is no reliable way of knowing unless a third party tests the helmets. DOT does not test very many, and there is now easy way to find out which ones were tested.
Bottom line: without any other data, a Snell helmet has more "proof" of safety than one that is not Snell approved.