Just switched to hi-Mile oil for my wife's car (corolla with 260K or
so) last summer.  Due for first oil change since the switch, next
week.

Why did I switch from regular "dino" to high-mileage?  Simple, just
about all the high-mile oils at my local store were CHEAPER than the
regular dinos...don't know why....maybe they weren't selling?  Maybe
they  had been on the shelf so long that the prices hadn't been
updated to reflect the recent soar in oil prices.

Anyway, that was the ONLY reason I went with it (it's one of the big
brands Quaker, Valvoline, Pennzoil, or something, don't feel like
slogging out to the barn to see).

But, you know something, the car used to eat about a quart or so of
oil between each oil change, and this time it appears to have only
consumed about a quarter of a quart (8oz or so).....Maybe just a
quirk....maybe the stuff really did help. Not sure, but if the prices
are comparable again when I go to buy next week, think I will use the
high-mileage again.

And, a bit off-topic, but if the hi-miles are significantly cheaper,
does anyone know if it will do any harm to use in my "less high-mile
engines?  It wasn't a major difference in price, 50 cents a quart or
so if I recall, but by the time I buy some 16 quarts of oil or so, it
adds up to $8 bucks or so,,,,which pays for a six-pack or two...