Sequentialtaillights.com presents a bulb survey comparison below
Brake/Turn Signal Bulb Survey using existing published specifications
3496 Krypton is basically 25% more energy efficient and 34.3% more CP (candlepower) output over the 2057 stock bulb The degree of "efficacy" is also notable here (ratio of light from lamp lumens to watt consumed). In effect, the lower the number the better the bulb.
Candlepower Output in a Modified 3 Lamp rear lens array
3 bulb output (2057 @ 12.8 VDC) = 96 CP using 80.64 watts.
3 bulb output (3496 @ 12.0 VDC) = 129 CP using 81.00 watts (at .8 VDC less!)
Using this bulb is like getting 1/3rd more "light" output at no extra cost in basic energy usage.
Not a bad deal in any manner. The rated life of these bulbs is shorter than the 2057, so you can expect to replace them at somewhat shorter invervals if you do a lot of night and city driving.
This particular bulb is OEM for many parts vendors like Honda, Sylvania, G.E. Lighting and are easily found at almost all automotive parts stores (PepBoys, Advance Auto, NAPA, AutoZone, etc.).
They will be in the package labeled #3496. It may be in a GE or Sylvania blister package but the bulb(s) on the inside the package will be stamped "STANLEY" and will have a SILVER base. These are made by Stanley Electric Co., LTD., a subsidary of Yokahoma Electric Corp. of Japan.
UPDATE: In recent years; GE and Sylvania blister pkg's have contained bulbs now mfg'd in TAIWAN and are silver base. They do not have the manufacturer name of Stanley stamped on the bulb, nor is the wattage or CP indicated there either. Only the #3496 number. I was informed by a Sylvania sales representative that it is indeed a true identical bulb, simply made in Taiwan and not Japan. My comment to him was, if this is indeed an identical bulb, why did Sylvania neglect to publish CP and WATTAGE spec's for this bulb on the package, like they do on all their other bayonet based automotive replacement lamp products. He had no answer to this question.
Now, K-Mart sells a Phillips #3496 but this does not have the same light output spec's and I have yet been unable to obtain a white paper on this bulb from Phillips. Since there is no CP info on the product package, I surmise its just a standard 32 CP bulb or 1157 replacement. I would not waste my money on these.
This bulb is available through Honda parts as well. The Honda part number is 34906-SL0-A01 and retail for about $5.00. You can even find these bulbs at your local WALMART store under the GE or Sylvania labels in the automotive lighting parts area.
Look at using these bulbs and the LBM-II bucket mod for Impala/Caprice to drastically increase the light power output of your rear lighting system without overloading the wiring or control switches (brake, stalkswitch, etc.). Up to 300% increase in power can be obtained on some aspects of the rear lighting.