OE Tires: Load index and safety?

Discussion in 'General Motoring' started by Charles Lasitter, Apr 8, 2005.

  1. So the Michelin MXV4 S8s on my new Accord can handle up to 1400
    pounds at 44psi, and that's all great. But Honda sets the required
    pressure at 30/29 for this particular car ('05 4Cyl 5M LX), and that
    begs the question:

    At those tire pressures, how much weight can the tires carry?

    Guess what: As owners, we don't get to know.

    With every PSI that you drop in inflation pressure, the max load
    capacity drops as well. And this number is different for ever tire
    on the market.

    So I figured that since this is important safety data, tire makers
    would certainly post their load index charts on their web sites so
    that you could know the limits of the tire at different levels of
    inflation. This is, after all, important safety information.

    But no. Turns out that all this info is sent to a trade association,
    called the National Wheel & Rim Association, where it's compiled, and
    then SOLD at $70.50 per copy under the "Wheel and Rim Yearbook"
    title.

    And of course with rapid changes in the market, it is obsolete before
    it's ever printed.

    Consumers Union has already complained about this in a filing to
    NHTSA, all to no avail.

    So just in case someone has this info for the stock Honda tires, I'd
    really appreciate it if you could share it with me.

    -- CL.

    +-----------------------------------------+
    | Charles Lasitter | Mailing / Shipping |
    | 401/728-1987 | 14 Cooke St |
    | cl+at+ncdm+dot+com | Pawtucket RI 02860 |
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    Charles Lasitter, Apr 8, 2005
    #1
  2. I did get an answer to this already, but still do not know where the
    information is on line that I could reference it without fee.

    -- CL.

    +-----------------------------------------+
    | Charles Lasitter | Mailing / Shipping |
    | 401/728-1987 | 14 Cooke St |
    | cl+at+ncdm+dot+com | Pawtucket RI 02860 |
    +-----------------------------------------+
     
    Charles Lasitter, Apr 8, 2005
    #2
  3. Charles Lasitter

    SoCalMike Guest

    its like the point that a cow might make- a moo point.

    its not just the tires/wheels, but the suspension, as well. i wouldnt
    overload the car. just because you set the pressures to 44psi doesnt
    mean you can use the trunk to haul a pallet of sand.

    id follow what they say about load, but wouldnt be afraid to play with
    the pressures a bit. worst case is you get a harsher ride.

    how much weight do you *want* to carry?
     
    SoCalMike, Apr 9, 2005
    #3
  4. Charles Lasitter

    TeGGer® Guest


    That's the "Tire and Rim Yearbook", not "Wheel and Rim...".


    Yeah, but your tire was made in a certain year, and will be included in
    that year's Yearbook, which at least one of your local tire shops ought to
    have.

    Have you tried phoning around?
     
    TeGGer®, Apr 9, 2005
    #4
  5. Well, the names MAY have been changed to protect the guilty ...

    http://www.nationalwheelandrim.com/

    now the National Wheel and Rim Association (NWRA), was apparently
    once the Tire and Rim Association, and published the Tire and Rim
    Association Yearbook, not to be confused with the Tire Industry
    Association, which has it's own slew of publications it wants you to
    buy.

    And if that's not confusing enough, NWRA also sells the Wheel and Rim
    Manual, which isn't the now Wheel and Rim Yearbook(??).

    I'm too embarrased to call them back and ask for clarification of all
    this again, but anyone that wants to can call 330-666-8121, and
    they'll be more than happy to sell you something.

    They don't have an on-line subscription option, which is what they
    really need to stay current, but if you want to go electronic,
    they'll sell you the database on CDROM for just $232.
    I don't think they'd like to hear from someone that was going to be
    placing an order thru the Tire Rack, but as far as currency of
    information goes, since I'm really interested in what's up with tires
    on the market right now, it'd be a hit and miss proposition.

    http://tinyurl.com/4bxmq

    This is what every manufacturer should have on it's web site, but for
    some reason, I'm only seeing it for farm tractors and trucks.

    I'll keep looking.

    -- CL.

    +-----------------------------------------+
    | Charles Lasitter | Mailing / Shipping |
    | 401/728-1987 | 14 Cooke St |
    | cl+at+ncdm+dot+com | Pawtucket RI 02860 |
    +-----------------------------------------+
     
    Charles Lasitter, Apr 9, 2005
    #5
  6. http://www.falkentire.com/tires_512_sizes.htm
     
    Steve Bigelow, Apr 9, 2005
    #6
  7. First, here's the proper nomenclature of what I'm looking for, and
    then why:

    "load and inflation table:

    A chart in the tire manufacturer's data book listing the carrying
    capacity of a tire at each of several air pressure increments from
    the lowest range of practical usage to its maximum capacity."

    Having this info would let me safely replace the OE tires with other
    tires of a slightly different load category by minor (one PSI)
    adjustments in pressure.

    That's because my 1400 max load tire at 44 max PSI is being run at
    30/29 PSI to generate an effective max load of about 1280 or so.

    With the right table data, you can jigger the pressure so that the
    replacement tire has the same effective max load at a given PSI as
    the OE tires did.

    (BTW: Did stumble upon something like what I'm looking for:)

    http://tinyurl.com/6kv5y

    Why bother with this? Well, sometimes the tire you'd like to run
    isn't available in exactly the right size or right load index rating
    or what have you, and it's nice to have some flexibility rather than
    just putting a much heavier load rated tire (and lots more unsprung
    weight) on the car.

    So I'm really not interested in towing anything or even carring more
    than a couple hundred pounds of rock salt. Just want some
    flexibility in the process.

    -- CL.

    +-----------------------------------------+
    | Charles Lasitter | Mailing / Shipping |
    | 401/728-1987 | 14 Cooke St |
    | cl+at+ncdm+dot+com | Pawtucket RI 02860 |
    +-----------------------------------------+
     
    Charles Lasitter, Apr 9, 2005
    #7
  8. Not quite what I wanted, but falken has the closest to what I'm
    interested in:

    http://tinyurl.com/6kv5y

    Thanks.

    -- CL.

    +-----------------------------------------+
    | Charles Lasitter | Mailing / Shipping |
    | 401/728-1987 | 14 Cooke St |
    | cl+at+ncdm+dot+com | Pawtucket RI 02860 |
    +-----------------------------------------+
     
    Charles Lasitter, Apr 9, 2005
    #8
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