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Owner: mpg_numbers_guy
Silver Aero (Personal Driving): 2004 Honda Civic EX Sedan Automatic
Displacement: 1.7 L
Fuel type: gasoline
Transmission: automatic
Curb weight: 2668 lbs
Coefficient of drag: 0.32
Frontal area: 22.5 sq.ft.
Instrumentation: Torque app
Description: 2004 Honda Civic EX Sedan in silver, nicknamed Silver Aero, purchased with 152.7K miles.

A lot of my driving is pizza delivery, which is logged on here on a separate fuel log. Been averaging ~38 MPG during pizza delivery, with almost zero hypermiling.

Winter reduces fuel economy by approximately 10%.

Stock drag: .32
Estimated ecomodded drag: .29

-26 city
-35 highway,
-30 combined
Current w/ no hypermiling
-36 city
-42 highway
-39 combined
Current w/ mild hypermiling:
-53 city
-47 highway
-50 combined
Current w/ max hypermiling
-65 city
-56 highway
-61 combined

Daytime driving speed: 25-50 MPH, depending on traffic. More traffic requires more 50-55 MPH driving.

Nighttime driving speed, no traffic: 15-40 MPH. With traffic my speed is the same as during daytime.

Estimated current weight from weight reduction: 2535lbs
Build Thread: Ecomodding an automatic '04 Civic Sedan
Current Mods: Current ecomods:
  • Hypermiling
  • No AC and limited radio use
  • Lawn edging air dam
  • HX rims
    • From 18lbs to 11.5 lbs per wheel, 27 lbs saved total
    • From 16.5 lbs to 16 lbs per tire, 2 lbs saved total
    • 29 lbs saved total (approx. 91.1 lbs of rotational mass removed)
  • Narrower 185/70R14 all-season tires (stock tires were all-season 195/60R15)
  • Tires inflated to 68 PSI*
  • Fog light covers
  • Adjustable foam insulation grille block, upper and lower.
  • Rear smooth wheel covers
  • Partial rear wheel skirts
  • Weight reduction
    • Full rear seat delete (-29 lbs)
    • Passenger seat delete (-37lbs)
    • AC blower fan delete (-7 lbs)
    • 3 of 4 headrests deleted (-3 lbs)
    • Glove box compartment (-4lbs)
    • Board and mat covering spare tire area (-14lbs)
    • 3 of 4 floor mats deleted (-10lbs)
    • Total weight deleted: 104lbs

Previous Ecomods:
  • Tail Extension (removed due to inconsistency in MPG improvement)
  • Mirror Boattailing (removed due to instability above 45 MPH)
  • Front smooth wheel covers (caused brake heating during longer periods of driving. Unnoticeable unless coasting or monitoring fuel economy, but can cut MPG by 50% until cooled off. Negligible FE loss from removal)

Next Ecomod:
  • Coroplast rear wheel spats

* = My personal recommendation is to not go over 60 PSI in 44 PSI rated tires.

Planned Mods: Other planned ecomods:
  • LED brake lights ($19)
  • LED interior lights ($7)
  • LED reverse lights ($16)
  • LED headlights ($37)
  • Attempt at homemade VGs to keep airflow attached down the rear.
  • Aero/low profile windshield wipers (if/when current ones need replacing) -$18

Ecomods under consideration:
  • Rebuild tail extension out of coroplast
  • Coroplast front wheel partial skirts
  • Redo mirror boattails
  • Windshield wiper deflector
  • Weather stripping to seal gaps around front hood and rear trunk
  • Further weight reduction (theoretically +1 mpg per 100 lbs deleted)
    • Full AC delete (-40 lbs)
    • Radio delete (-20 lbs)
    • Speaker delete (-8lbs)
    • Total: -68lbs, theoretically +0.68 MPG.
  • Engine pay underbody paneling from same gen Civic Hybrid or a belly pan
  • Power steering delete
Official Fuel Economy Ratings
EPA city 26 mpg(US)
EPA highway 35 mpg(US)
EPA combined 30 mpg(US)

Actual Fuel Economy Performance
Lifetime 45.84 mpg(US)
Last 3 tanks 50.98 mpg(US)
90 days No data entered
View Fuel Log
Last updated: Aug 20, 2018

(Created: 2018-02-14 22:45:32 / Modified: 2018-11-23 15:31:35)

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