170 Starting and driving

Economical motoring

How to read the graph above:

 

 

If fuel consumption with the engine at

Factors affecting fuel

normal temperature is 28 mpg

consumption

(10l/100 km), the actual fuel consumption 3

miles (5 km) after the engine has started

Fuel consumption is greatly affected by the

from cold will be:

general driving conditions, the way in which

23.5 mpg (12l/100 km) at outside temp.

the car is driven and at what speeds, the

 

of 68°F (20°C) (increase of 20 %).

weather, the state of the road, the condition

 

17.7 mpg (16l/100 km) at outside temp.

of the car, etc.

of 32°F (0°C) (increase of 60 %).

Breaking-in

Fuel consumption may be somewhat higher during the break-in period (the first 3,000– 4,000 miles (5,000–7,000 km) than stated.

Weather conditions

Fuel consumption can be as much as 10 % lower in summer than in winter. The higher consumption in cold weather is explained by the longer time it takes for the engine to reach normal operating temperature, and for the transmission and wheel bearings to warm up. Fuel economy is also affected by the distance driven: short journeys of 3–5 miles (5–8 km) do not give the engine enough time to reach normal temperature. Strong winds can also affect fuel con- sumption.

14 mpg (20l/100 km)) at outside temp. of –4°F (–20°C) (increase of 100 %).

As can be seen, both the distance travelled by the car and the outside temperature have a major impact on fuel consumption after the engine has started from cold. Thus, if the car is mainly used for short journeys of 3–5 miles (5–8 km), the fuel consumption will be 60–80 % higher than normal.

IB311

Percentage increase in fuel consumption of engine starting from cold compared to engine at normal temperature

Page 170
Image 170
Saab 2007 owner manual Economical motoring, Factors affecting fuel, Consumption, Breaking-in, Weather conditions