WaltBJ wrote:

More trivia on flight and oxygen:

snip

As for the Rocky Mountains, when we get flatlanders up here for a
visit and take them for a drive up over Trail Ridge road - peak
altitude about 12,200, they usually doze off because they won't
breathe (pant) enough.

(Almost totally OT) Ah, Trail Ridge road. When my '88 Subaru GL Turbo 4WD
Wagon was almost brand new, I took four people and all our gear for a week
over Trail Ridge (we'd driven from California, but spent a night and half
day in Great Basin Nat. Park, including sleeping at 10,000 feet). The
Subaru only had 115 hp and had a curb weight of about 3,000 lb., and
virtually everyone had a better power/weight ratio and was faster than I
was -- at sea level. So there we were, climbing up the west side on a
hot, muggy summer day (it was in the high '80s or low '90s, I forget
which, when we passed through Granby @ 8,500 feet), and all of a sudden I
found I was just about the most powerful car on the road, as I passed what
were far more powerful cars (at sea level) while driving uphill at ca.
10,000 ft. I could drive as fast as I wanted to (max. 40-50 or so) uphill
on the fairly open two-lane road, with 1-2,000 foot dropoffs on the side
and usually no guardrails on the turns. Coming back over from east to west
was the same.

I never did find out what the critical altitude on the turbo was, but
judging by its performance on Trail Ridge that day it must have been well
over 14,000 feet (allowing for density altitude). Couldn't have a more
clear illustration of a turbo's thin air performance advantage than that.
I later took the car up to 13,200 feet in the White Mountains one
September with two people and gear, and I don't remember any altitude
problems there either, at least for the car (it was graded gravel and
dirt, so I wasn't driving very fast in any case). Both of _us_ had AMS
from ascending too fast from sea level, even though we'd slept at 9,000
feet the night before.

My Subaru Forester (some SOB stole my old Subie in its fifteenth year, or
I'd still be happily driving it) doesn't have a turbo (they only came out
with the XT turbo model in June or so of last year, and I had to buy a car
that January). It's got about 165 hp and more torque, so my old turbo
would come up short up to about 8,000 feet or so, but have more power
above that. Living in the SF Bay Area at sea level and driving up to the
Sierra it hasn't been a problem so far, but I have yet to carry that much
of a load that high, that hot. The highest paved road in California goes
over Tioga Pass (9,941 ft.) in Yosemite, and it handled that fine with two
people and backpacking gear last August, so I probably don't need a turbo
here, and I'm happy not to have to worry about the turbo blowing up or
suffering other expensive problems (not that I had any, but I changed my
oil every 3,000 miles and let it idle down properly after hard driving).
But if I was living in Colorado up against the Front Range and/or
commuting across it, I'd sure want one. I've read that Subaru developed
the Turbo Forester XT precisely because the normally-aspirated model was
left gasping for breath commuting through the Eisenhower tunnel (@11,000
feet). As Homer Simpson might say, "210 hp all the way up, M'mm."

Guy