Altitude vs air density vs power

[Petrus]

Perhaps not so much of a subject in the UK but in many parts of the Continent it is. For mé it is a daily thing. More even than temperature.
Just going down to the coast means an altitude difference of 1100 metres.
A longer fun trip can see 2000 meter easily.
A rule of thumb is 1% per 100 meters.




Remember the temperature one?





Go figure if the engine would heat up the intake flogging the car up into the mountain passes on a hot day with low barometric pressure 

[1979scotte]

@Petrus
#firstworldproblems

[Petrus]

@Petrus
#firstworldproblems

The whole forum no?!

[Ardent]

Somewhat different to your home land, that can be below sea level.

Things life can throw up. Eh!

[Zxrob]

So haw would this effect your drive, if you are not, on, or close to the limits constantly

Rob

[Petrus]

Somewhat different to your home land, that can be below sea level.

Things life can throw up. Eh!

When faffing with 2strokes on the track the same issue applied to atmospheric pressure, temperature and humidity resulting in an relative air density value for the correct jetting.
Also, going to Belgian or a German track added enough meters altitude to make a difference.

[Petrus]

So haw would this effect your drive, if you are not, on, or close to the limits constantly

Rob

Dunno :-)

I suppose it would affect your fuel efficiency, autonomy.

Seriously; it is most notable when overtaking, especially uphill overtaking. 25% power loss adds 25% more meters (a bit more actually but that is nit picking) and that is a nice to know.

The Stelvio pass, in the UK made so famous by the TG clowns, is 2700 meters or so high and going up from Bormio an n.a. car will be sériously slowed down.

As I wrote, not thát marked within the UK but on the continent it can be, for me it is; I live at 780 meters p.e.
Say 20 hp power difference on the same day, same outing,  is quite normal, is noticeable ;-)

[shnazzle]

It's hilarious to read about the Pikes Peak cars an show much HP they lose as they go up