# High altitude driving

```Haudi,

"ec" mag (Aug, '97) was kind enough to post the SAE correction factors
for standardizing Hp figures.
ALTITUDE      CORRECTION         INVERSE
0             1                  1
1000          1.035              .966
2000          1.072              .932
3000          1.115              .897
4000          1.158              .864
5000          1.200              .833
6000          1.249              .801
7000          1.295              .772
8000          1.345              .743
9000          1.400              .714
10000         1.455              .687
11000         1.514              .660
12000         1.570              .637
13000 (ng)    1.628              .614
14000 (ng)    1.688              .592
14110         gasp!              ahhh!
(ng) indicates figures not given. I used a cheezy extrapolation for 13k
and 14k

If your car is dyno-ed above sea level, multiply the indicated Hp by the
CORRECTION to get SAE sea-level figures (neglecting temp and humidity
factors).

Ex. Dyno at 4000 ft. Shows 738 Hp.
738 Hp * 1.158 = 855 Hp (I have a spearco the size of my garage on the
4kq)

If you're driving in the mountains, multiply your known (ie, from
owner's man) Hp by the INVERSE to get your available Hp.

Ex. Manual shows 115 Hp. Driving at 14000 (top of PP).
115 Hp * 0.592 = 68 Hp. Can you say diesel Jetta????????

O'course none of this applies to the Audi turbos, unless they reach
overspeed.

Yet another benefit to NA Audis (ie, most non-pentosin rigs) is loss of
braking boost. Your power brake booster works using the difference in
air pressure between ambient and the canister (engine vacuum). If the
ambient pressure goes down, so does braking boost. Your brakes _should_
work as well as they do at sea level, you just have to push harder on
the pedal. But, don't forget the boiling point of the brake fluid will
decrease, too. (affects repeated stops) Also, the coolant's boiling
point will go down. Hmmm, maybe I should move to Nepal or Chile to
capitalize on these "benefits" . . .

cu
James

```