Part specifications serve an important aspect in choosing the correct part. The SparkPlugs.com Family of sites has multiple tools to assist you in deciphering part numbers and features.
Part Number Charts:
From any page on the site, click on the "Learning Center" link in the footer.
Click on "Charts & Tools".
Use the Heat Range Conversion Chart to compare the heat ranges between spark plug brands.
Use the Autolite Numbering System to decipher Autolite's part number system.
Part Specification Listings:
All available part specifications have been included in the part details page.
Use the site search box to find the part number you wish to see the specs for. Click on the "Product Specifications" tab. Available specs may include dimensions, features, materials, longevity and warranted life.
Use the "Compare" button to select up to 4 parts within the same product type and compare their specs. Available specs may include dimensions, features, materials, longevity and warranted life.
Click the "Compare" button on all parts you'd like to compare the specs on.
Click the "Compare Now" button when you're finished selecting parts.
Click the red "X" next to a product to remove it from the comparison, or click "Clear list" to remove all items.
Examples of how to use these tools...
#1 - What is the difference between Autolite 104, AP104, APP104 and XP104?
Using the Autolite Numbering System, we see that the prefix letters designate a spark plug series. 104, without a prefix, would be a standard spark plug, AP104 is a platinum spark plug, APP104 is a double platinum spark plug, and XP104 is an Xtreme Performance spark plug, Autolite's iridium/platinum series.
We can confirm by comparing the specs for these plugs, which confirm that 104 is a standard nickel plug, AP104 is a single platinum plug, APP104 is a double platinum plug, and XP104 is an iridium/platinum plug.
#2 - When searching for 104, there are 3 different versions. What is the difference between Autolite 104, 104BP and 104DP2?
Differences in spark plug specs can be found in the specs tab, however, the bullet points can be helpful in explaining any packaging differences.
#3 - What is the difference between Autolite 103, 104, and 106?
Again using our Autolite numbering system, we find that the last number designates the relative heat range within a spark plug family. Within the 10x family of plugs, 103 is colder than 104 and 106 is hotter than 104.