Does Gravitational Variation Affect Fuel Consumption on Identical Roads?

[y33t]

Hi all,

Problem ; Why a car consumes different amounts of fuel on two different roads with same characteristics only with different locations ?

Assumptions;

-Amounts of fuel consumed, lengths and slopes of two roads are measured precisely.
-Two roads are built from the identical material thus friction force is same in both.
-Car has the same load including driver in both two measurements.
-Identical fuels are used in both two measurements.
-Car was driven with identical characteristics in two measurements.

Surely there might be other parameters that needs to be considered for performing such a comparison but these are the ones that comes to my mind mainly.

My potential explanations ;

1- Gravitational distribution on Earth or object due to space is not homogeneous ?

2- Different altitudes have different pressure values that can directly/indirectly effect the operation of the internal combustion engine

 

[voko]

Wind. Temperature (of air, tyres, road). Humidity.

 

[y33t]

Wind. Temperature (of air, tyres, road). Humidity.

Temperature is the same as well.

Wind and humidity ; up to what percentage can these parameters be effective ?

Let's say 10lt/100km for no wind and humidity is at reference cell.

What would the average wind and average humidity correspond to in liters/kilometers ?

 

[voko]

For wind, much depends on the shape of the car and the direction and the strength of wind. It is not entirely implausible to speculate that it is possible for a car arrive at its destination by wind alone.

I am less sure about the temperature and humidity, this will require a careful analysis.