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Old 09-01-2014, 04:09 AM   #9 (permalink)
EcoModding Lurker
Join Date: Aug 2014
Location: Toulouse, France
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News with the Smart :

According to Scangauge I'm currently on a 4.5L/100km tank ! (52 US mpg)
First tanks were around 5.8L/100km (40mpg), last one was 5.0L (47mpg)
Changes between those tanks :
- warmer weather (but not much, this summer is really bad in France ; maybe 10°C more today than in April when I bought the car)
- new oil & oil filter (5W30);
- new air filter (old one was really dirty !);
- tire pressure from 2bars to 2.2 then 2.4bars (29 to 32 and 35 psi);
- smoother driving, slower acceleration, lower rpm gearchange ;
and probably the most important:
- "summer traffic", MUCH less traffic during July and August compared to rest of the year.

I didn't measure every improvement separately ; I will see in September if I go back to 5.8L/100 with traffic jams...

The really smooth accelerations and low-rpm gearchange do not seem to make that much difference, according to Scangauge : last week I had one commute when I was in a hurry, and had something to hold in hand (I know, it's bad ), so I push a little harder and used the "auto" gearbox mode, which shifts around 3500rpm. Still did 4.2L/100km (56mpg) on that commute !

The new oil & filters did not change my highway fuel economy either : 5.9L/100 (40mpg) on 80% highway tanks, both before and after the oil and filter changes.
The car has short gears (its half sports car/half city car, definitely not a highway car) and quite bad aerodynamics, despite very small front area. Plus, I'm driving at 130km/h (81mph) (I know, this is bad also )...

I have the "roadster" version (blue one on the picture below) ; the "roadster coupé" (grey one) has a better shape, basically it has a factory kammback added. .
According to Wikipedia, Cd value is 0.41 for the Roadster, and 0.38 for the Roadster Coupé !

EDIT: I found the CdA also !
6.41 sq ft = 0.596 m2 for the Roadster Coupé;
6.94 sq ft = 0.645 m2 for the Roadster.

Last edited by Kara; 09-01-2014 at 04:23 AM..
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