Priority Mail is has 2-3 day delivery (almost always 2 days) for $4.95. The Post Office provides a small box (8-5/8" x 5-3/8" x 1-5/8") that you can use. You can take extra boxes home with you for the next shipment (or to practice assembling the box without any tape if you are box challenged).
Make sure there is plenty of stuffing (newspaper, etc) so the contents don't rattle inside the box. If the postal worker asks you what it is, say motor oil. If they ask you if it is new or used, say new.
You can print the label online, and get a tracking number (they only track delivery) included in the price.
.......... If the postal worker asks you what it is, say motor oil. If they ask you if it is new or used, say new..............
I was asked "new or used" for the first time a few weeks ago. Must be a new USPS policy. USPS says shipping used motor oil via 1st class (i.e. via air transport) is a no-no, but Blackstone claims it is OK.
I put the sample in the clean bottle that Blacksone provides. I then put the glass bottle in the zip-lock plastic bag with the information and slip the sample into the cardboard tube and cap. I take it to my P.O. and mail the cheapest way and I have my results on my computer within two weeks.
I have never shipped to Blackstone, and maybe the Post Office is wise to what they do, but I have shipped many Priority Mail small boxes for stuff I sold on Ebay and no one at the Post Office ever asked me what was in it. But make sure it doesn't rattle.
I just mail the black plastic bottle first class. Never had any trouble (except for the one time the P.O. confused the FROM and TO addresses and delivered it back to me the next day).
Results usually come back anywhere from 9 days to two weeks. I was told (here on the forum) it all depends on how busy the lab is.
I packaged mine per the Blackstone instructions, but then placed it in a small shipping box after hermetically sealing the sample bottle in a food-saver vacuum bag (didn't pull a full vacuum, though). Sent it US mail, first class ($2.50). I dropped it at the PO on a Friday afternoon, and had my results emailed the following Tuesday - a total of 5 days. I was stunned.
My post office has no issues mailing any oil. I walked in, told her what it was (they mail this sort of stuff quite frequently apparently), and since I kind of know her too (my mother used to work there), she got me a box and some of those air pads for the box since just mailing the round, black bottle "wouldn't be such a good idea." Anyways, mailed it Prioirty Friday afternoon, and I had my results from Blackstone in my e-mail inbox Monday morning. Not too bad for $4.95 IMO.
I mailed it yesterday in an envelope that cost
$1.39 and the postage was $2.36 and they said it should arrive within 2 or 3 days and I also asked to know when it is delivered and got a little paper with which I can go online and get info the total was $4.50. Never done one before and this was the 4th oil change on a new car so while I can!t compare it to anything it will let me see how the oil is working and I asked for a tbn also. They did ask if it was liquid and I said yes and he asked me what and I said used motor oil. I showed him the letter and he said ok. He did write liquid on the outside but not what type.