David, your source is outdated as NOVA production was discontinued a few
years ago. The lowest grade is Magna Sin. I have used it for 10 years in
Baja and it performed fine in all of the Vanagons I have taken there. I
have never bought the Premium grade. I have at least 40,000 miles of
Vanagon driving experience in Baja with no fuel quality trouble.

I have not used much gasoline on the Mexican mainland so I can't say
what the situation is there. I have bought a bit of diesel fuel there
with no problems.

Mark

David Beierl wrote:
>
> That would fit with these remarks from
> http://www.rversonline.org/ArtMexFuels.html -- according to him (her?) even
> the mid-grade is less than 87 "American" (R+M) octane.
>
> >NOVA
> >
> >Novas, is the lowest grade of gasoline and also the most common. It is
> >sold out of Blue dispensing pumps, and is popular with
> >Mexican drivers because of it's price .......
> >

> >MAGNA SIN
> >
> >This mid-grade fuel is sold from a bright green pump, and is Mexico's most
> >popular unleaded gasoline. It's octane level is
> >somewhere around 86, and is superior to the silver pump "Extra" which it
> >replaced in 1990. Most vehicles will run acceptably on
> >"Magna" (as it's popularly called in Mexico)........

> >PREMIUM
> >
> >Mexico's newest gasoline, is also it's best effort to date. Unfortunately
> >Premium gasoline is found only in larger towns and
> >cities, and will slowly migrate outwards to medium size towns.............