Thursday, December 19, 2013

Drivin' in the rain

Rain has an adverse effect of mileage.
Here's a trip at 3 degrees with clear weather: 20.43 km/l (4.89 l/100km)

And the same trip with 2 degrees and light rain: 19.01 km/l (5.26 l/100km)

Wednesday, December 18, 2013

Increasing engine temperature for fun and gain

Following my previous investigation about temperature effect on mileage, I tried covering the front grid to help the engine gain and maintain temperature.
The first tests on my daily commute trip seems encouraging:

Trip with no radiator cover: 18.46 km/l (5.42 l/100km)

Trip with radiator cover: 20.43 km/l (4.89 l/100km)
Net gain: 0,53 l/100km
Given that with a full tank of gasoline I drive for 700 km, that leads to rougly 3.7 litres of gasoline saved, or 6 Euros at the actual fuel price.
The radiator cover cost me 5 Euros, so I''ll begin saving money at the first refuel.

Sunday, December 15, 2013

Ambient Temperature effect on Mileage

Temperature are falling quickly these days.
We've fallen from 9 degrees to 2 degrees recently.
Here is a mileage chart of my daily trip at 9 degrees:
Mileage was 21.29 km/l (4.7 l/100km).
Here is the same trip but with 2 degrees ambient temperature:
 Mileage was 18.46 km/l (5.4 l/100km).

Lower temperature affects engine temperature: lower values lead to lower efficency and higher consumption.
The HV battery can provide less current, so EV mode can't be used as much as in summer.
Even low speed starts cause the engine to turn on.
Car heating worsens the situation even more, causing the engine to run just to produce hot air.
This can be seen in the ICE statistics:
At 9 degrees, ICE is off 40.1% of the time
At 2 degrees, ICE is off only 36.9% of the time.

By comparison, here is the same trip with hotter weather in November (I wasn't tracking temperature at the time):

Mileage was off the scale at 25.4 km/l (3.9 l/100km), but I've scored even better values in the summer.
ICE was off 60% of the time.