A smart enthusiast from St-Jean-Port-Joli, Quebec has posted a record tank in his 2006 smart cdi, which has the 799 cc 3-cylinder turbo-diesel currently unavailable in the United States.

Over the course of five days, his car used just 23.8 litres to go 1063 kms. That’s an astounding 660 miles on 6.3 US gallons.

Fuel economy summary:
2.238 L/100 km
126 mpg imperial
105 mpg US

Incidently, this essentially matches the fuel economy I achieved almost exactly a year ago!

Serge wrote at clubsmartcar:

These are the intermediate results written down from the scangauge every day numbers, but adjusted by a percentage with the final pen & paper results. They are not fully accurate but fairly enough for comparaison purposes.

Description of the 5½ legs :

Leg 1 : Cacouna NE : wind NE 10 knots, june 7, early morning 5°C up to 12°C later, all highway except 20 km RR.
Leg 2 : L’Isle-Verte NE : wind SO light, june 8 am 12°C , all highway except 41.3 km RR.
Leg 3 : Beaumont SW : wind south light, june 9 am, 19°C, all highway except 16 km RR.
Leg 4 : Montmagny SW : windless, june 9 pm, 23°C, all RR (rural roads).
Leg 5 : Cacouna NE : wind NE 10 knots, june 10 am, 13°C , going highway and return main 2 way road.
Leg 5½ : Final laps : many loops RR and up last hill home, to empty tank to 0.0 liters display.

Intermediates results :

Leg 1 : 231.1 km on 5.3 liters and 2.295 li/100.
Leg 2 : 252.4 km on 5.75 liters and 2.278 li/100.
Leg 3 : 162.3 km on 3.3 liters and 2.036 li/100.
Leg 4 : 87.9 km on 1.95 liters and 2.217 li/100.
Leg 5 : 237.2 km on 5,3 liters and 2.186 li/100.
Leg 5½ : 92.5 km on 2.2 liters and 2.378 li/100.

Serge’s car is pretty much stock, except for an improvised throttle control he fabricated and installed. He also uses a Scangauge to monitor live fuel consumption, turbo boost and engine load. He had discussions with other owners including myself at gassavers.org and clubsmartcar.ca while embarking on the hyper-economy challenge.

Throttle control

I will try to take picture of my trottle control. In words it is a fake pedal over the original one, having the same hinge at the base but being 5 cm away at the top. it protude over the original and is linked by a nylon string to a small pulley behind the pedal. The pulley diminishes the amplitude by half. It is kind of ugly for the first try ( make the picture shy to be publish on the forum), but so efficient that I might make a permanent alu one.

It serves two purposes :
1) Better trottle control by moving with more amplitude than the original, and

2) half the pressure necessary on the pedal, pressure I complained about here last summer.

The hand lever is even more accurate moving 10 cm for a 1 cm movement of the pedal. (Editor’s note: In other words, engine load can be maintained very constant when a Scangauge is used in conjunction.)