Ill give you that, the 25k miles is pretty ridiculous. I will still advertise 15k though because thats relistic to what ive read. And they do have cheaper oil that comes out to the same price as in store.
No, they're not the same price. Especially not when you apply $15 shipping and still have to wait for it to be delivered. Shit by the time, you throw their sales tax and shipping cost on there, you could order some damn good Joe Gibbs Driven oil from Summit for cheaper with no sales tax (depending on what state you live in) and free shipping over $100.
From what I've seen through my own testing and others is that Amsoil OE is pretty much dead nuts comparable with base synthetic Mobil 1.
Mobil 1: $6.97/qt ($25.47 for 5qt jug) at Walmart, there and back home in 15 minutes. Just bought this yesterday for my wife's Nissan and reading right off the receipt.
Amsoil OE: $7.45/qt + $8.50 S/H for 5qts and not able to buy it in a 5qt jug. Forced to buy by the quart or buy a damn drum or tote. Total is over $45 and you have to wait a couple days at least for it to be delivered to you.
I also paid $2.81 less for the WIX filter I picked up than it would've cost me through Amsoil and again, grabbed it right off the shelf. Looking it up online right now, Autozone, Advance, O'Reilly's, and Pepboys all carry the same WIX filter between $1.95 and $2.92 cheaper than Amsoil's website.
Now this is not including a "preferred customer" discount. You pay $20 for the damn membership which means you have to spend near $100 just to break even on the membership fee. Unless you're spending $100+ a year on oil (which I'd say 95% of Americans aren't), it's a wash. In fact, better make that $150+/yr if you want to get back your shipping cost which means you're still getting fucked.
Also throw in that Castrol GTX and Valvoline are right there with Mobil 1 in quality and are $8 and $3 cheaper respectively per 5qt jug than Mobil 1. All full syn.
I really do like Amsoil. Their oil has performed well in my cars and the lab analysis shows that. However, I can't justify the price when off the shelf oil is 97-98% as good. The only vehicle in my yard that still gets Amsoil is the 66 Coupe. It gets Z-Rod 10w30 for it's old worn out flat tappet 289. My wife's Nissan and my MX5 both use Mobil 1. The Mustang won't be staying on Z-Rod however. Once the new engine is ready, it'll be getting replaced by Joe Gibbs Driven because, once again, I can go pick it up off the shelf for cheaper and have it same day.
I went 11,400 miles in my MX5 on Amsoil SS 5w20, and it needed to be changed. I don't drive that car hard. It's just a commuter. The Amsoil Dominator oil and Z-Rod are about the only one's I'd say are somewhat worth it but that's a very niche market. You also need to have an active racing program to justify purchasing a drum or tote to make it somewhat justifiable over running Valvoline VR1, Joe Gibbs, or Brad Penn.