Sunder wrote:

maby wrote:

... OK - clearly there will be one, but I was watching the numbers yesterday and I was surprised at how great it is - has implications for assessing performance...

You know, I was able to push my old 1.8 tonne car on flat ground. Surprisingly, I can't bench or dead lift more than 100kg. Gravity, hey?

You know that to overcome wind resistance and frictional resistance for most cars at 60km/h is in the single digit kilowatt range? But a decent hill climb on a 1.8 tonne car can push you over 100kw just to maintain speed.

Put into that perspective, maybe it should be surprising that hills only cost 25% more.

We are talking about 150 m over 25 miles. That is roughly a 1:250 ratio, which will add 7 kg gravitational force, or something like that? Sure you can push your car up a 1:250 ratio.

EDIT: To lift 1800 kg up 150 m you need 1800 kg * 9,81 m/s2 (at least where I live) * 150 m = 2648700 Joule. This is the equivalent of approx. 0.74 kWh. Lets say a liter of petrol contains about 9.7 kWh of energy and burns at an efficiency of 25% (which is a negative estimation), then you need about 300 cc of petrol to concur gravity. Normally, 25 miles will take about 3 liters or so? So, an additional 10% to 'get up there'?