Register Now
 Register Now

Now available from EcoModder: ScanGauge II fuel economy gauge.  Click for details.  

You must sign in to add / modify vehicles in the EM garage
Owner: California98Civic
Black and Green: 1998 Honda Civic DX Coupe
Displacement: 1.59 L
Fuel type: gasoline
Transmission: manual
Curb weight: 2262 lbs
Coefficient of drag: 0.32
Frontal area: 20.4 sq.ft.
Instrumentation: UltraGauge
Description: I have three goals with this car. First, average 60+ mpg while averaging the posted speed limits. I get there sometimes. Second, make the car cheap to own. I'm currently about $1800 ahead in ecomodding costs/savings since Feb 2011 (see bottom of this page for accounting in blue print). Third, save on depreciation and interest payments and divert savings into investments. I currently put $200/month aside.

OEM data sheets:
Transmission swap: 1993 Civic CX (see below for details of the mod) with 93K miles on it (March 2013).
Odometer calibration: I am running the stock 13" VX wheels all around with Michelin Defender (175/70) on the front and Michelin Harmony (175/70) on the rear. GPS and route mapping suggest a 2.9% odometer undercount with this combination (my calibration thread for details The Michelin Harmonys do 923 revs per mile, but the Defenders are rated slightly slower at 917/mile according to
Speedometer calibration: The VX wheels (& Michelin Defenders) on the front appears to create a slight speed overcount. The 1996-1998 Honda Service Manual says the gauge reports 60mph when the VSS turns 1,025rpms and the 1992-1995 manual says 60 mph at 1026 rpms of the VSS. The speedometer gears in the two transmissions both measure 90.6mm using vernier calipers. So the differences in speed and distance calculations are due to wheel/tire size combinations.(cite)
Cd: ~0.28 (an 0.04 reduction estimated using this Hot Rod Magazine article).
Engine type: D16Y7 (106hp/103tq)
OEM tire: Firestone FR680, 185/65SR14 (23.5" diam. & 886 revs/mi.)
ECU: OBD2, Code P2E-L32
Color: Flamenco Black Pearl (Code NH-592P).
Manufacture date & place: Tuesday, 1/13/1998 at the East Liberty, Ohio factory.
Current odometer reading: 216,000 (passed 200,000 mi on 10/28/2012).
Current Mods: HYPERMILING (adjusting the driver nut is the single most effective "mod"):

I always use EOC and P&G on surface roads, and a mix of these and "GLEN" on the freeways. I also use MPG-optimized routes, trip combinations, and driving times as much as my commuter schedule allows.

AERODYNAMIC (listed according to what I think most on EM would agree is the most to least effective):

2.5" lawnedging airdam
Side skirts v2.0 (cut rain gutter, flat black paint)
Full upper grill block (v2.0) & 80% lower block (v1.2).
175mm wide tires all around (stock was 185).
Passenger mirror replaced with internal convex.
Half-moon style wheel skirts version 2.0 (see version 1).
Mudflap delete.
Passenger-side wiper delete (and RainX application).
OEM antenna moved behind windshield, which is painted black at the top with plasti-dip
Thrush Turbo muffler (smaller than OEM, better for planned belly pan's rear diffuser).

MECHANICAL/ELECTRICAL (listed according to what I think most on EM would agree is the most to least effective):

1993 Civic CX transmission with 93,000 miles on it (installed when odo read 203,000 miles). In fifth gear it provides a 20% rpm reduction over my stock DX coupe gearing, and about a 25% reduction in rpms in 4th gear. Compare ratios here. And here is how I dealt with one PITA part of the swap.

An injector kill switch
Tires inflated to 60psi.

An "Externally Powered Electrical System" (I plug the car in when I'm home). The set-up combines an alternator on/off switch, 7 LED brake & running lights and a H4/HB2/9003 HID kit for the headlights, a deep-cycle Odyssey PC1200 battery with metal jacket & XSP-586 SAE post adapters (installed @192K miles), and a 25-amp on-board battery charger. I've also pulled one of two 5w license plate bulbs. For notes on why the 25 amp charger is important see this post.

A Warm Air Intake (WAI). And CAI/WAI manual switching ability for hottest conditions.

Alignment set to "zero toe"

Advanced ignition timing to 14 degrees BTDC (currently at stock 12*).
13" wheels and 175/70s (replaced 14" 185/65s).
New Micheline Defenders (LRR) on front wheels.
Used Michelin Harmony Tires on rear wheels (once considered LRR).
NGK single-platinum spark plugs.
Radiator/grill ducting (v.1.2).
6K oil change schedule.
Fully synthetic Mobil 1 "Fuel Economy" 0W-30 (5w-30 currently).
Tried Royal Purple 5w30 oil in the manual transmission, and it worked fine in the 98 DX but I switched to 10w40 in the 93 CX transmission.

WEIGHT REDUCTION (probably most effective in city/P&G driving):

251lbs removed (to approx 2011lbs* curb weight):
9.7lbs VX wheels (replaced 18lbs alloys), 9lb thrush muffler (replacing 18lb OEM), AC, rear seats, power steering, and numerous other things small and large.

* = Includes 33lbs for front passenger seat delete (often reinstalled).

ECOLOGICAL FOOTPRINT: Some hypermiling techniques might raise certain emissions when engine is running. But radically cutting overall fuel consumption reduces the average emissions per mile. Cutting fuel consumption in half also halves my contribution to demand for fuel, which produces pollution in production and very high emissions in distribution via super tankers (3, 4, 5).


Sites for parts, besides my local Autozone and O'Reilly: a, b, c, d, e, f, and g.

Tires & wheels (besides ebay & CR): a and b.

Calculators: standard deviation, Ohms Law, & drag HP losses


Fiberglass or carbon fiber panels (if replacements ever needed)
Lighter rear brake drums from 1st Gen Insight (if replacement needed one day): Insight drums weigh about 4.6 lbs ea and the Civic OEM drums are a little over 6lbs *


Would consider a Boomslang harness (BF08003 for the 1996-1998 Civic) and an APEXI SAFC2 in order to produce my own version of "lean burn," but it would require converting to a wide-band O2 sensor and an EGT sensor. That would not be easily reversible for California emissions tests.

Lighter flywheel (perhaps from a VX or HX) when the clutch finally fails. The stock DX flywheel is about 20lbs and the stock VX is about just under 16lbs.

Lightweight crank pulley, single belt conversion with harmonic balancer, maybe when I do the timing belt.

Possible wheel swaps for gearing/weight advantages:
13" Civic VX 8 spoke (higher RPMs but only 9.7 lbs.)
14" Civic HX 8 spoke (approx 11 lbs)
14" Civic Hybrid 2003-2005 (approx 14 lbs)
15" Mini Cooper R81 Imola 7-hole (12.1 lbs)
15" Mini Cooper R86 star-spoke (15 lbs)
15" Mini Cooper R96 7-spoke (13.8 lbs)
15" Enkei Classic J-speed (14.1 lbs)
15" Enkei RP-F1 (9.5 lb)*
15" Kosei K4R (10.7 lb)*
15" Konig Helium (11.2 lb) 40mm offset, hub bore 73.1mm*
15" Acura Integra GSR (94-95, 16lbs)
Other size specs to double-check for any possible swap: Offset 35-45; bolt pattern 4X100; lug size 12mmX1.5; hub center bore 56.1mm minimum (larger needs spacer rings). For more info see 1, 2, and 3 (for general wheel size data across models).

Brake drag reduction mod: drums and discs.

LRR tires, when I wear out these baldies: Nokian eLine should be available USA 2014


Rear wheel skirts (brackets)
Rear box cavity
Small flat rear trunk lid spoiler
Partial bellypan

GENERAL REPAIRS in PLANNING STAGES (in order of priority):

Timing belt (& add lightweight crank pulley w/ balancer)

Investigate themostat/hoses for cooling system periodic leak cause.

Chase-down oil leak (probably oil pan gasket)

Bleed brakes and inspect pistons (possible brake dragging).

Replace driver's outside door handle (already acquired junkyard replacement, sanded, and painted it).

Fix rapid/slow directional signal problem (ground? relay?).

Cabin fan noise (is a leaf stuck? replace filter?)

Clean the CAT with citric acid before 2014 smog test. Also see this thread.

Rebuild DX trans using VX final drive gear and a rebuild kit from Synchrotech or another company.


Considering just the costs of modding against my savings in gas, I'm currently about $1800 ahead since Feb 2011.

But keeping the car is also an "ecomod" that saves plastics and metals and money: I avoid car payments, costlier insurance, and newer vehicle depreciation. My insurance is $500/yr less than my wife's 2010 Subaru. And as for depreciation, if I had purchased a new Civic in October 2011 when the first serious mechanical failure occurred to this one, the new Civic would have depreciated $2200-$4000 per year. A three year old one would have depreciated $1300-$2400 per year. And the opportunity cost would be about $18,000 minimum over 10 years ownership, assuming 5% growth in other investments.

Ecomodding is also how and why I began learning DIY auto repair, which is the only way to save on mechanics. Since January 2011, I have completed a tune-up and five oil changes, and three tire rotations. I have replaced the MT fluid, distributor, cap and rotor, sparkplugs, coolant, tires, muffler, front brake pads, O2 sensors, both drive axles and CV joints, the clutch release "slave" cylinder, both front driver side balljoints, the front driver side hub bearing unit, and the transmission (so I can rebuild the original tranny without losing my daily driver). In terms of bodywork, I have repainted items that often chip off paint after many years (wipers and window framing) and the plastic trim parts that become dull after years of sun exposure. And I sanded and polished-off heavy headlight oxidation.

Gasoline $2686
By extending oil change schedule: $25 per 6K mi. x 6 = 150
Royal Purple instead of Honda MT fluid (in former trans): $8
By extending previous muffler life: $2/mo. x 11 = $22
By extending use of former tires 28K miles: $100
Savings ~ $2966 Feb 2011 through March. 2014

Costs of ecomods:
Ultra Gauge 69
VX 3.25 final drive and countershaft 58 (for the rebuild of my old DX trans, not yet installed)
Thrush muffler & weld (cost over OEM): 30
Coroplast 30
PVC Plumbing pipe 10
ABS pipe and caps 25
Dryer hose 5
Convex mirrors 13
Lawn edging 10
Freon draining 50
Tape 35
Velcro 10
Zip ties 10
Goo Gone 5
Great Stuff 7
OEM AT selector knob (new) 39
Inline ATO fuseholder 3
12, 14, 16, 18 gauge wire 15
Terminals and splicers 2
Switch for injector kill-switch 8
Switch for alt cut-off 4
Misc hardware 48
Gasoline for testing 35
7 LEDs (brake, run, other) 114
First deep-cycl batt (-Interstate batt price) 28
Odyssey PC1200 deep cycle battery $222
25 amp battery charger 160
6 amp on-board charger 70
1.5amp on-board maintainer 30
On-board digital volt meter 29
HID headlight adapter kit 70
Reybestos brake clips (now given away) 10
Subtotal 1243

Costs of comforts and fun
Ecomodder and other stickers 17
Top grade, metalized tint 200
Sheepskin seat covers 116
Dashtex dash cover 30
MP3 aux line equip 49
Accessory charger (iPod & phone) 10
Plasti-dip 12
OEM color spray paint (Code NH-592P) 25
Subtotal 459

Costs of tools & repair parts (not "mods"):
Actron scan tool 130
Kobalt jack & stands (on sale) 130
MityVac vacuum pump 32
Torque wrench 70
Voltage meter 8
Wrenches & sockets 78
Timing light 39
Tin snips 15
Hacksaw 8
Oil filter wrench 5
Breaker bar 18
Replacement ratchet 12
Pin punches 15
Pry bar 10
Distributor 200
Left drive axle 50
Right drive axle 50
2 O2 sensors
Transmission (needed replacement) 300
Throw-out bearing 100
Clutch slave cylinder 45
2 trans seals 30
VX wheels (for tires w/ wheel bonus) 300
Drivers front hub bearing unit 54
Use of press: 40
Lft-frnt lowr balljoint 57
Use of press: 20
Lft-frnt uppr balljoint & cntrl arm 40
2 13" Michelin Defender tires 190
Mounting/balance 2 tires 50
Wheel alignment 59
Subtotal 2155
Total hardware/parts/tools costs since Feb 2011 = $3521[/i]

$2966 (saving) - $1244 (ecomod cost) = +$1722
(+$1263 if including comfort stuff and -$892 if including ecomods, tools, repairs and repair parts, and comfort stuff.)

Secondary savings guestimated rule of thumb: about $209/month. I get that number by estimating $2000/yr average in vehicle depreciation (starting Oct 2011) plus $500/year auto insurance (starting 5/2012) = $3458 as of April 2013. I add this amount to my retirement account through autodeduct from my paychecks.

Official Fuel Economy Ratings
EPA city 27 mpg(US)
EPA highway 34 mpg(US)
EPA combined 30 mpg(US)

Actual Fuel Economy Performance
Lifetime 61.37 mpg(US)
Last 3 tanks 62.94 mpg(US)
90 days 62.46 mpg(US)
View Fuel Log
Last updated: Mar 30, 2014

Trip Log
AV 64.7378 mpg (US)

(Created: 2011-03-06 10:29:32 / Modified: 2014-04-08 08:58:18)

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright