You are correct - the Amsoil XL-7500 oil has been changed to Group III, which Amsoil announced to the world and declared in full at the time of the reformulation. They did it to keep up with other oil companies who were selling Group III oils as "full synthetic" and pricing Amsoil out of the building. Here is the full info:
Action News: AMSOIL will be using a different formula for its XL-7500 Motor Oils. Why did AMSOIL change the formula?
Amatuzio: Our XL-7500 oils are the oils of choice in the retail oil change market, and primarily because of warranty concerns the customers in this market require API-certified. In order to obtain API SL/ILSAC GF-3 certification and still remain cost-competitve with the other oils sold at retail oil change outlets, we had to change to Group III basestocks. To obtain API certification with our top tier basestocks would have priced our Dealers out of the market.
Action News: Are Group III basestocks synthetic?
Amatuzio: Yes, they are synthetic. Group III base oils are highly processed oils and were classified as synthetic in 1999. That year, the National Advertising Division (NAD) of the Council of Better Business Bureaus ruled in a complaint by Mobil Oil Corp. against Castrol North America Inc. Castrol claimed its product, Synthec, was a synthetic oil even though it had used Group III base oils since 1997.
Action News: How did that change impact the lubricant industry?
Amatuzio: Initially, the decision by NAD shocked the lubrcant industry. However, many studies show that Synthetic Group III base oils have been completely changed and converted and are significantly different from traditional Group I mineral oils. They have come to be recognized in the industry and by consumers as synthetic.
Action News: Are all Group III oils equal?
Amatuzio: No, as a matter of fact, they are not. One of the big problems with Group III base oils is the lack of consistency from one manufacturer to another. While the physical properties may meet performance parameters, the performance characteristics can vary widely. That's because of differences in the crude oil and the different processes used to refine the crude into Group III basestocks. It's quite different from PAO production where the properties and performance are fairly consistent between manufacturers. (See Table 1.)
Action News: How did AMSOIL resolve these differences in performance characteristics in the Group III basestocks?
Amatuzio: AMSOIL has selected the best quality Group III base oils and spiked them with oxidation inhibitors and TBN. They have more gusto than other Group III oils and are fully formulated for 7,500-mile drain intervals. (See Chart 1.)
Action News: What prompted the new GF-3 designation?
Amatuzio: The new designation was driven by three key performance requirements:
improved fuel economy, improved protection of emissions control systems and the need for more robust engine oils that offer extended drain intervals.
Action News: What does the new formulation mean for AMSOIL Dealers?
Amatuzio: The new formulation allows Dealers and customers to save money. Effective July 1, the XL-7500 5W-20, 5W-30 and 10W-30 motor oils cost 20 cents per quart less for all programs. Retail on-the-shelf cash commissions change form 15 to 20, consistent with all other AMSOIL products, and commission credits in the MLM program remain unchanged.
Action News: Are the other AMSOIL motor oils impacted in any way?
Amatuzio: Our other motor oils remain unchanged. They are the very best quality synthetic motor oils, formulated for 25,000 mile, or one-year drain intervals. Our main line motor oils are the premier, top quality oils on the market and that is where they will stay. Unlike the competition that considers Synthetic Group III a major step up in performance, our PAO-based motor oils are still the best.
Action News: How are basestocks defined and classified?
Amatuzio: The American Petroleum Institute classes basestocks in five Groups, defined by sulfur content, saturates and viscosity index. Groups I and II are petroleum-based oils. Group III, as mentioned before, have been most recently designated synthetic, Group IV synthetic basestocks are PAO chemistry. Group V represents all stocks not included in Groups I-IV, such as esters, silicones and polyglycols.
Action News: Why did AMSOIL choose to use Group III basestocks in these particular oils?
Amatuzio: The AMSOIL XL-7500 oils are particularly appropriate for Group III basestocks because they are stable and resist oxidation and volatility. They are recommended for only 7,500-mile, or six-month, drain intervals. Primarily sold to the installed retail market, they give the retailer and customers what they want and need for their vehicles.

So Amsoil did what the market forced it to do to stay competetive, but it still makes the Group III base stock as "high quality" as it can with additives to keep it's products superior technologically.

Laters......

:) As of Thursday afternoon of the first week on Amsoil 0W-30 oil, mpg per the car computer is still sitting firmly at 37.8, thus still showing an increase of 1.1 mpg with the new oil. No dropoff yet, after about 170 miles this week of about 90% city stop-and-go with the A/C blasting, average high temp in Phoenix this week 106 F......

Will post final mpg for this tank on Monday morning, since I will be filling up over the weekend......

LSS

I think these small variations may have nothing to do with the oil change.
I drive the exact same route to work 17.2 miles.
I drive exactly the same way.

My MPG varies from 60 to 65.
May be wind direction.

Yes, I certainly understand basic variations of the HCH mileage computer. But what I have seen is different in that I never was getting more than 36.7, then immediately on the first trip after chaning the oil I got 37.8, and it has remained steady at 37.8 for more than 5 days in a row - that's pretty consistent, no?

I have seen this before in a 1997 Suburban I had. I took it back and forth from Texas to Phoenix and never got more than 17 mpg on the trips. Then I changed to Amsoil and on the first Texas trip about a week later, I got 19.3. So I have prior evidence of how reduced friction of Amsoil can impact mileage.

There are also countless other examples of Amsoil users who have seen increases in a wide variety of cars. It's not incredible or amazing, but any little thing that helps can't be bad, right?

Laters......

Re: Do you change your own oil?
 

I change my own oil in both my 03 Civic hybrid and my 03 VW TDI wagon.
Both of these vehicles, as previously mentioned, have that aerodynamic skidpan under the engine block. The local JiffyLube charges $9 EXTRA just
to remove and replace this cover during their oil change.

I bought ramps and an 07400 Fluid Evacuator from MityVac. Now I just vacuum out the old oil from the dipstick access.

The Civic still has the oil filter that is best accessed from below. The VW diesel's filter is on top.

Also, if you break or loose any of the plastic do-dads that hold the Honda's skid plate on you can buy new ones from you Honda service department. I bought enough spares to replace all for about $7. A previous owner had used zip-ties to fix a couple of missing fasteners.

Hope that helps...