I found this on the Snell web page
"The Snell Memorial Foundation, Inc. has finalized its SA2015 Standard for Protective Headgear which applies to auto racing helmets. However, although there are several changes in test requirements and procedures from the current SA2010 Standard, Snell certified auto racing helmets are expected to stay very much the same as they are now.
Changes include:
* SA2015 helmets must be ready for the addition of frontal restraint tether hardware such
as used in HANS® and other systems.
* SA2015 includes provisions for “Low Velocity” impact testing.
* SA2015 includes “Low Lateral” impacts in case of strikes against side window frames and
similar structures.
The projected timeline for SA2015 is as follows:
* SA2015 Certification testing has already begun.
* SA2015 Certified helmets will not be available for sale until October 1, 2015, when the
standard takes effect.
Our advice to Safety Inspectors and Racing Authorities is that they continue to accept helmets in good condition and certified either to the current or immediately previous Snell standard. At this time, SA2010 is the current Snell standard and SA2005 is the immediately previous.
Snell urges everyone to replace their Snell certified helmets routinely no later than five years after the helmet is first worn. However, even by this conservative advice, many current SA2010 certified helmets still have years of service in them. Unless a helmet has been damaged, or has five or more years of use, or is no longer accepted by safety inspectors or track authorities, there may be no need to replace it.
Please direct any questions, comments and requests for copies of the SA2015 Standard to
info@smf.org or call 916-331-5073"
So there are some small changes in the testing and certification so If you buy the SA2010 you can save some money and have a good usable helmet (till 2022)