The Mental Acrobatics Needed to Apply LATCH Weight Limits

This article originated in the July/August 2013 issue of Safe Ride News.

As most readers have probably noticed, we are going through a particularly complex period with respect to determining LATCH weight limits.  Most CPSTs have heard about upcoming changes in FMVSS 213 regarding lower anchor weight limits.  NHTSA has ruled that, by next February or sooner, CRs must have instructions and labels limiting use of the lower attachment system to a child weight specific to each CR model.  This weight limit is to be calculated based on the formula “65 pounds minus the CR weight.”  Keeping things interesting, this final rule is under further review, and NHTSA may or may not announce a modification to it in coming weeks.  Though this ruling pertains to CRs only, many vehicle manufacturers indicate in the 2013 LATCH Manual* that they have adopted this same formula to express lower anchor limits (and tether anchor limits, too, in some cases).  So this limit now applies to about half of all vehicle brands.

As February 2014 approaches, CPSTs have many valid questions:  Do CR weight limits reflect child weight only or are they based on this formula that includes CR weight (often called combined weight)?  Does information in the LATCH Manual  supersede information in the vehicle manual? Are these new limits retroactive? Do the limits apply to use of a tether, too?  And, what if the CR and vehicle weight limits differ?  We will address each of these questions here.

Are lower anchor usage limits today based on child weight or the child-plus-CR weight?

This has been the source of much confusion lately.  Up to 2013, nearly all the weight limits given by both CR and vehicle makers reflected a maximum child weight only (Subaru being the sole exception).  However, research for the 2013 LATCH Manual* found this has changed as follows:

Vehicle manufacturers (VMs): Many (27) vehicle brands reported a new weight limit, which is a combined CR-plus-child weight of 65 pounds.  (This may be described in terms of a child-weight limit by the formula “65 pounds minus the CR weight,” as we have done in the 2013 LATCH Manual.*)  However, it is important to note that nearly half do not state this formula;  be sure to apply that limit only to vehicle brands for which it is stated.  For brands that do use this formula, the 2013 LATCH Manual* supplies weights of current/recent FF CR models in Appendix A (at the end of each CR brand entry) and a cheat sheet for subtracting from 65 pounds (at the end of Table B2, page B-5).

CR manufacturers (CRMs): The CRMs always express the weight limit for use of the lower attachments in terms of the allowable child weight.  When NHTSA’s upcoming CR requirements go into effect (so that the use of the lower attachments will be limited to a combined weight of 65 pounds for all CRs), the CR labels and instructions will nonetheless state this in terms of a child-weight limit (per the wording requirements of NHTSA’s final rule).  In other words, though the CR makers will be required to apply the formula using the CR-model weight when determining the child-weight limit, the limit that will appear in printed instructions and labels will simply be the child weight (which will vary depending on the particular CR model weight).
[Note:  Some CR manufacturers have indicated that they consider it an option to round the limit downward.  It is possible that some may do this in order to maintain a consistent limit among their various model offerings.]

If the LATCH Manual and the product instructions and/or labels differ, which should be followed?

First, be sure you are looking only at a 2013 LATCH Manual*; all other versions are now outdated and should not be used.  Also, understand that the CR and vehicle information in Appendices A and B of the 2013 LATCH Manual* was supplied and approved by the manufacturers, so it represents the most up-to-date information from the manufacturers at the time of LATCH Manual publication (December 2012).  So, like the manufacturers’ instructions/manuals, the LATCH Manual is a valid source of instructions provided by the manufacturer.

In general, rely on the printed source of manufacturer information that is the most recent.  This means looking at the print date of the document that comes with the product. If the 2013 LATCH Manual* states something different than what was printed previously in a CR instruction booklet or vehicle owner’s manual, then use the information provided in the LATCH Manual, since it represents more-current manufacturer specifications. If the product manual was printed more recently, however, go with that.  If you are not sure which is the most recent, or have any other concerns, always contact the manufacturer for additional direction.

Vehicle manufacturers: Although some VMs have made changes to anchor limit specifications over time, this actually hasn’t often resulted in a conflict between the LATCH Manual and the vehicle owner’s manual for one simple reason: most vehicle brands do not address anchor limits in their printed manuals (although more are now stating that they have begun or plan to do so). Therefore, the LATCH Manual provides an important means for vehicle makers to communicate these weight limits.  For the few brand exceptions that have printed limits over the years (Ford brands), the information in the LATCH Manual matches the owner’s manuals.

CR manufacturers: When it comes CRs, however, lower attachment use limits are  usually printed in the CR instruction booklets, especially in recent models that are not yet expired.  The LATCH Manual is generally in sync with what’s printed in the booklets for unexpired CRs.
As CR manufacturers begin to comply with NHTSA’s new rule for labeling and instructions, however, it is likely that some limits given for new CRs on labels and instructions will differ from the limit that the manufacturer stated in the 2013 LATCH Manual*.  In fact, a few new models have already come to market with a lower attachment system limit that has been stated to comply with the new rule, and this sometimes does differ from what’s stated in the LATCH Manual.  When this is the case, follow the CR instructions for the particular CR, since they provide the most current information (checking print dates once again).  (Note: Another twist is that some CR models may include the NHTSA-required weight limit information in the product instruction booklet before this information is added to labeling.)

Are weight limit changes retroactive?

Although it is always important to read instructions for exceptions, the general answer is:

  • Vehicle anchor limits stated in the 2013 LATCH Manual* are retroactive to all
    vehicle model years, according to the VMs (unless otherwise specified).
  • CR weight limits for using the lower attachments are not retroactive.  They
    are specific to the CR unit being used.

Here are some details about these general rules:

Vehicle manufacturers: The weight limit information found in Appendix B of the 2013 LATCH Manual* with respect to vehicle anchors now applies to all vehicle years of each brand, retroactively.  LATCH weight limits can be found among the bullets at the beginning of each brand entry. (The weight-limit-specific bullets are always at the top of the left-hand column.)  The weights for all brands are also summarized in Table B2 (pages B-4 and B-5), which includes a note clarifying that the information is retroactive unless otherwise stated.

There are two main vehicle exceptions:

  • Ford brands (which do print limits in their manuals) will switch to the limit of “65 pounds
    minus the CR weight” in model year 2014, when they can insert this change into the
    manual-printing pipeline.  This change will not be retroactive, however, as Ford
    has indicated that it has opted instead to maintain the weight limit that matches what is
    printed in each vehicle’s owner’s manual.
  • Chrysler makes certain exceptions by model and year, only for tether anchor
    limits (see the tether section below).

CR manufacturers: Guidance for CR models is not expected to be retroactive. NHTSA has not required that the new limit be applied to older units of the same CR model.  Therefore, information provided in the 2013 LATCH Manual* should align with the requirements printed in most current manuals, and this direction will continue to be appropriate for models from this time period.  However, when the new CR instructions/labels required by NHTSA begin to appear, it will be important to follow the limit given for the specific CR unit.  The label on the CR will be a key indicator.

What limits apply to tether use?

To answer this question, a distinction often needs to be made regarding whether the tether is being used with lower anchors or with a seat belt and whether the anchor is factory installed or retrofitted.

Vehicle manufacturers: In Appendix B of the 2013 LATCH Manual*, there are three types of vehicle tether anchor weight limits listed for each vehicle brand (in the brand bullets and summarized in Table B2 on pages B-4 and B-5).  They are:

  • Complete LATCH system: one weight limit that applies to all the anchors of a LATCH system when used together (LAs and TAs) or LAs used alone for RF CRs.
  • Seat belt installation instead of lower anchor use: the tether anchor limit may be the same as the limit for the complete LATCH system, but often is higher.
  • Retrofit TA limit (for pre-LATCH vehicles): may be lower than the factory-installed TA limits.

Several vehicle brands, including all General Motors and VW/Audi/Porsche brands, extend the lower anchor child-weight limit formula of “65 pounds minus CR weight” to tether anchors, too.  Many other brands, however, provide a higher weight limit for TAs if the seat belt is used for installation, rather than the lower attachment system. In fact, 23 brands state to follow CR manufacturer’s instructions regarding tethering limits when used with a seat belt (which essentially means to tether at all allowed forward-facing harness weights).  Chrysler allows this on many specific models/years (see the Notes section for individual Chrysler, Dodge, Ram, or Jeep/Eagle models).

CR manufacturers: When it comes to tethering, CR manufacturers nearly always recommend use at all harness weights.  Check the language in the manufacturer’s Appendix A entry of the LATCH Manual to see which also defer to the vehicle limits for TA use, if lower.

I’ve figured out the correct CR and vehicle limits, but what if these differ?

As always, it’s important to know both the vehicle and CR manufacturer limits.  If you find that these differ, most manufacturers say to follow the lower of the two.  Switch to installation with a seat belt when in doubt.

Vehicle manufacturers: Thirteen vehicle brands defer to whatever limit the CR manufacturer states for lower anchors, and even more—23—do so for tether anchor limits when used with a seat belt; this is noted in the LATCH Manual as “Follow CR instructions.”  Unlike in the past, this provides clear guidance for today’s products, since all CR manufacturers now state a limit for their current CR models (which may be the same limit as the maximum harness-use weight).  So when the VM states to “follow CR instructions,” go with whatever limit the CR manufacturer specifies.  For all other vehicle brands that specify a limit, there is no leeway provided to defer to the CR manufacturer.  Four brands (Isuzu, Tesla, Suzuki, and Mazda) do not provide a stated limit, in which case the current CPS curriculum (10/2010) indicates that a limit of 40 pounds should be assumed.  (The forthcoming curriculum update may or may not change this.)

CR manufacturers: Although all CR manufacturers state a limit for installation with the lower attachments (which may be “all harness weights”), nearly all also defer to the vehicle manufacturer’s limits.  (However, check the language in the product instructions and/or the manufacturer’s Appendix A entry to see whether they defer to vehicle anchor weight limits that are lower or higher than their own.)  Instructions for Diono’s Radian CRs with SuperLATCH advise lower attachment use at all harness weights, regardless of the vehicle manufacturer’s stated limit, if the vehicle was made after September 1, 2005. (Note, however, that at this time, vehicle manufacturers that state anchor limits have not approved this usage exception.)