Originally posted by RogerB:
OK, so rather than just guessing, I ran the whole exercise again.

Comparing the two oils, yes, Amsoil beats Mobil 1 on VI, Flashpoint, and pour point, but both oils are superior to anything else I found data for. (Remember we're also trying to stay close to the same price point.) Enough said about that.

According to the Amsoil website, their 5W-30 is $5.85/quart. Take that times 6 (if you don't know why, search) and add shipping and it comes to $41.80 per oil change. The 5-quart Mobil 1 jug, plus an extra quart, plus tax, comes to about $26, locally.

Now, the argument is that because Amsoil can be changed less frequently, it's actually cheaper. That's true for some. Is it true for me?

Amsoil's recommended change interval is 25,000 miles, or once a year. As I said earlier, my yearly average is only 8,000 miles. That translates to a Mobil 1 oil change about every 7 or 8 months. If I start with an oil change in January of 2004, and run the intervals and costs out on both oils as far as the year 2027, the Mobil 1 is still cheaper by about $40 dollars. (By then I'll be 60, and my Contour will have about 250,000 miles.)

Now, $40 may not seem like much, and you could argue that it's worth more than $40 just to do fewer oil changes. But in the here and now, time and sweat are cheap, and money is tight.

Of course, all of this is based on current prices and car usage. If anything changes, I'll have to reexamine. And in 24 years, a lot can change.



First off, Rog, apologies for the format-confusion. I didn't mean to imply that your oil preference is driven by "quasi-religious" brand devotion.

By using the "quote" reply mode, I was trying to maintain the overall context of the exchange ... And signal that all further CEG'er "contributions" amounting to little more than a "my-oil's-better-than-your-oil" pissing contest will be ignored.

Your reasons for preferring M1 seem quite sound to me. And, frankly, even if I thought otherwise, I wouldn't question your judgement.

Like I've said right along, I'm not on a mission. My comments about Amsoil are based on my personal experience over a long period of time and largely under extreme (XR4Ti turbo car + 12 Texas summers), "acid-test" conditions. Nothing more, nothing less.