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Old 08-11-2011, 11:47 AM   #51 (permalink)
Vekke
Mechanical engineer
 
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Join Date: Jan 2009
Location: Kitee (Finland)
Posts: 1,272

Siitin - '98 Seat Cordoba Vario
90 day: 58.56 mpg (US)

VW Lupo 3L --> 2L - '00 VolksWagen Lupo 3L
Diesel
90 day: 104.94 mpg (US)

A8 luxury fuel sipper - '97 Audi A8 1.2 TDI 6 speed manual
90 day: 64.64 mpg (US)

Audi A4B6 Avant Niistäjä - '02 Audi A4b6 1.9tdi 96kW 3L
90 day: 54.57 mpg (US)

Tourekki - '04 VW Touareg 2.5TDI R5 6 speed manual
90 day: 32.98 mpg (US)

A2 1.4TDI - '03 Audi A2 1.4 TDI
90 day: 45.68 mpg (US)

A2 1.4 LPG - '02 Audi A2 1.4 (75hp)
90 day: 24.67 mpg (US)
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there is engine brake possible on fifth gear also. Also next tank done once again I chickened out and made the fill too early. Anyway cars own fuel gauge is accurate. Gauge showed 3.0 l/100 km and calculated result was 3.066 l/100km. 80% of that tank I drove 100 km/h speed so there is only one liter which needs to disappear . Too sad that in pecentages that is 33%.

Starting point calculation:
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

My current estimations/calculation of my mods savings:
Aero 15% cd from 0.29 to 0.24
Tyres and Taller gears 10% RR 0.008 to 0.005 (calculator is not able to estimate taller gear effect so I put smaller value than it will propably be...
Engine effiecieny (tuning and ecodriving) 12% engine eff 0.36 to 0.41
weight loss of the car + driver=total mass (150kg) 3% 1000kg to 850 kg
100W less electrical load (led lights +xenons) 2%

http://ecomodder.com/forum/tool-aero...ToStep=40-65-1

What this means I need to use P&G when doing 100 km/h to get the engine effiency figure where I put it. Also the CD value is only 0.24 so its a great possibility that I dont even have to build a huge boattail etc. However if those calculations arent valid I can easily drop the CD to 0.2 which drops the calculation from 2.0 l/100km to 1.72 l/100km which should be still in my reach. Frontal area is only a estimation and that will get little bit smaller with mirrors and lowering and if need roof chopping. The roof is at least 80 mm too high for my 193cm body...

All comments welcome.

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Vesa Tiainen innovation engineer and automotive enthusiast

Last edited by Vekke; 08-11-2011 at 11:54 AM..
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