60+ MPG Civic Coupe (2001)

[TaylorL]

Hey all! First of all I'd like to say thank you to every one of you that makes this forum so great, I've been reading for a month or two and i love the friendly and helpful community you've all built for yourselves here.

So a little background on me, I've been a gearhead from a young age, starting with dirt bikes and quads then moving into cars, boats and airplanes. I bought my first mustang at 13 and started modding it into an autocross car right away. Since then i climbed the ladder, (grew up a little bit) and moved into the far superior corvette platform! I had four corvettes, raced and modded all of them, the most recent one being a Silver 2006 Z06. Efficiency was the last thing on my mind, it was all about speed and horsepower. The 600 Hp in the Z06 did just fine! Well about three or so years ago I started flying a lot more. The race cars weren't doing it for me so I sold my Z06, bought an airplane and never looked back. Best decision I've ever made. I'm now a professional pilot and work as a flight instructor here in Central California.

As I grew up even more my attention began to shift towards my future and my investments. I was driving 25,000 or so miles per year in my lifted LS swapped K10 getting 14 MPG! As much as I loved the truck I ran the numbers and by simply switching to a more efficient vehicle with MPG in the high 30's I was looking at a savings of $6000 per year!! That's fuel alone, not including the lower maintenance costs of a 4 cylinder engine and smaller brakes, tires, you name it. So I shifted my attention to the old beat down civic sitting in the corner of my moms yard.

We had bought the car when I was in high school for my sister and I to more efficiently make our 40 mile commute. After high school my sister took the car and i drove my trucks/corvettes. After driving it for a couple years with around 280k on the odometer my sister ran whatever life it had left out. Broken timing belt, blown head gasket, bad catalytic converter, bad oil consumption, leaks and failing smog. Most of this wasn't her fault of course, just typical of an old car. The good news is I was clever enough when buying the car to pass on anything four door and more importantly anything automatic. So what i had was a good enough civic coupe with a solid standard transmission and a surprisingly tight drivetrain that still tracked straight and drove well down the road. I pulled the car into the shop, did a full engine overhaul and now here we are, 315k miles and going like heck. Thus the "Savy Civic" was born.

I've been practicing hypermiling for the past couple years that I've been driving the car. I was averaging 42.7 MPG without* any EOC, pulse and glide, or DWL. I didn't even so much as shut the car off at red lights and all my deceleration was in gear using engine braking. Since I've gotten more serious in the last month my new average is now 47 with a high of 47.5 by using all of the above techniques and nothing more than a wiper delete. Although since adjusting driving habits my last three tanks have improved with every fill. 47.5 being the most recent. Even without mods I expect it to improve a bit more as that 47.5 number was set in unusually cold (california cold) temps, on winter fuel, with some rain and an ocassional spurt of traffic. I think the wipers were even installed for part of that, not to mention all the headlight usage this time of year.

Thus bringing us here. Having been inspired by AndrewJ, MetroMPG and basjoos I believe it's time to take my hypermiling to the next step. While I firmly believe the best "EcoMod" you can make is a driving style adjustment, some aerodynamic improvements can only help take me another step farther. I'm hopeful to get the Savy Civic into the mid 50 MPG range with a little aerodynamic help, although I suspect I could bust into the 60's with enough effort. I'm willing to get pretty carried away with mods with certain limitations. First they have to financially make sense. Any mod that doesn't net enough gain to pay for itself obviously isn't prudent. Even if it is fun. I also don't plan get so extreme as to dramatically alter the look or function of the car. This means no alternator delete, no boat tail and no fifth wheel. I also currently do not have a scangauge. Which means I am unable to do any proper testing to prove a mods effectiveness. This is something I'll consider in the future.

As the civic sits now I've done a power steering delete, wiper delete, and i'm finishing up the EOC kill switch today. Going forward I'm planning, mirror delete, partial grille block, full underbody aero, rear wheel skirts, smooth wheel covers and I may experiment with VG's if I'm feeling adventurous. I suspect any VG gains would be minimal on my coupe.

I'll throw up some pictures of my bland old coupe whenever the rain lets up here. All that said I'm looking forward to chatting with some of you and happy to be here!

[mpg_numbers_guy]

Welcome to Ecomodder!

I think you can hit 50+ mpg easily, and 60 MPG if you're careful. My last car, an 04 civic sedan, was able to average 45.8 MPG during the time I owned it, with many trips in the 50s and one highway trip just barely hitting 60.0 MPG with a tailwind (verified at the pump). Mine was an automatic, which is about a 10% FE handicap compared to a manual, so you have an advantage there.

Here's the link to my build thread to see what I did with mine: http://ecomodder.com/forum/showthread.php?t=36160

Note that the "70 mpg" trips claimed on some posts turned out to be false when verified at the pump - the Torque app overestimated around town fuel economy by about 20%, and underestimated highway fuel economy by about 20%.

Pump up those tires, but don't run over 60 PSI. 68 PSI made my Civic a little squirmy on concrete highway in strong winds. An inconspicuous air dam was worth a couple mpg. Lighter rims + narrower tires was another mpg or two.

Those 7th gen Civic are sweet cars.

[TaylorL]

Originally Posted by mpg_numbers_guy

the Torque app overestimated around town fuel economy by about 20%, and underestimated highway fuel economy by about 20%.

Thanks for the welcome! I've been looking at the torque app as a cheaper alternative to a scangauge for testing and monitoring purposes. Do you have any input on that? I do a lot of engine off coasting, one of my concerns is that the app may disconnect briefly when the engine is killed? I'm also curious if the torque app has a way of manually adjusting the MPG readout for accuracy?

Originally Posted by mpg_numbers_guy

Pump up those tires, but don't run over 60 PSI. 68 PSI made my Civic a little squirmy on concrete highway in strong winds. An inconspicuous air dam was worth a couple mpg. Lighter rims + narrower tires was another mpg or two.

Those 7th gen Civic are sweet cars.

I'm currently running 53 PSI, they were around 47 when i did that 47.5 MPG tank. I read a write up MetroMPG did about rolling resistance with higher tire pressures. I haven't yet done any testing of my own but it seemed like pressures beyond the max sidewall of 44 offered very minimal returns. As of right now I likely wont exceed 53, I feel that's a good safe number with reduced rolling resistance.

[mpg_numbers_guy]

Originally Posted by TaylorL

Thanks for the welcome! I've been looking at the torque app as a cheaper alternative to a scangauge for testing and monitoring purposes. Do you have any input on that? I do a lot of engine off coasting, one of my concerns is that the app may disconnect briefly when the engine is killed? I'm also curious if the torque app has a way of manually adjusting the MPG readout for accuracy?

Not really. Torque is good mostly only for instantaneous fuel economy - which isn't even accurate. All it's good for is seeing higher numbers is better and lower numbers is worse. Accuracy is garbage.

EDIT: One of the required settings for FE instrumentation with Torque is to input your car's engine size. Not sure what effect that has on changing the FE value; I never messed with it when I was using Torque.

For example, if your MPG is > 99.9, it will display up to 256 MPG, but it won't count any time above 99.9 MPG as part of your fuel economy trip log. Therefore any downhill driving on the highway wasn't always counted, hence why the highway FE was grossly understimated.

Torque also seems to underestimate how much fuel is used to accelerate. I could get the reading above 65 MPG by doing Pulse-&-Glide (which turned out to be 50-55 mpg max). The readings were artificially high because it didn't seem to account for how much gas was being used.

Maybe they've updated it since, but the only times I was able to get an accurate reading was when my split of highway/city driving was even enough where the +20% error and -20% error mostly canceled out. Or if when I drove on the highway I kept on the gas even on the downhill to keep the MPG just below that 99 mpg threshold, but that just resulted in a little lower MPG overall.

A Scangauge works best because you can calibrate it over a full tank. Is Torque better than nothing? Sure, any slightly accurate fuel ecnonomy instrumentation better than no instrumentation, but if you're looking for accuracy, don't look for a bluetooth dongle + smartphone app.

Originally Posted by TaylorL

I'm currently running 53 PSI, they were around 47 when i did that 47.5 MPG tank. I read a write up MetroMPG did about rolling resistance with higher tire pressures. I haven't yet done any testing of my own but it seemed like pressures beyond the max sidewall of 44 offered very minimal returns. As of right now I likely wont exceed 53, I feel that's a good safe number with reduced rolling resistance.

Yes, beyond 44 PSI and the gains are smaller; beyond 60 PSI and the gains are smaller yet. They're still there, but they're a lot harder to measured.

[TaylorL]

Originally Posted by mpg_numbers_guy

A Scangauge works best because you can calibrate it over a full tank. Is Torque better than nothing? Sure, any slightly accurate fuel ecnonomy instrumentation better than no instrumentation, but if you're looking for accuracy, don't look for a bluetooth dongle + smartphone app.

Yeah that's basically what I assumed. I wasn't exactly banking on the torque idea. There's no free rides right? One of these days I'll have to bite the bullet and get a scangauge. Until then I'll just have to track changes over averages from tank to tank.

[Vman455]

https://ecomodder.com/forum/showthre...upe-21526.html

[TaylorL]

Vman, your coupe looks awesome! What did you make your smooth wheel covers out of? I'm currently trying to find some pizza pans or something along those lines in just the right size to fit my 14" wheels.

[Vman455]

Thanks! Those were commercial covers; I think you can find similar if you google "moon disk covers" or similar.

[TaylorL]

Originally Posted by Vman455

Thanks! Those were commercial covers; I think you can find similar if you google "moon disk covers" or similar.

Ah roger that, thanks!

[COcyclist]

Welcome Taylor, I think you are on the right track with your planned mods. I own both Scangauge II and Ultragauge. I prefer the Scangauge for ease of use and small size, easy mounting. It is worth the money in my opinion. I recalibrate it every fill up in just few seconds. FWIW I tuft tested the windshield and A pillar area on my car and was surprised to find the tufts at the base of the windshield flowing forward and into the fresh air intake even on "recirc". There may be little to no benefit from the wiper delete.

Sealing the grill opening to the radiator with some foam may help slightly too.