8th generation honda civic mods?
 

Howdy everyone... i'm just starting to get into the whole hypermiling thing.

I have a 2009 honda civic EX coupe, 5 spd manual transmission. I have been averaging 37-38 mpg per tank, with a best of 40.5 mpg. my commute is 45 miles each way, with about 60% on the interstate.

Has anyone done any modifications to an 8th generation civic? i haven't been able to find any posts on here. What have people used for a grill block?

THanks,
Brandon

Welcome to the site Brandon.

I don't have a civic, but I'd recommend the grill block and pumping up the tire pressure as your first two mods. Good luck, you already seem to be doing pretty good.

Thanks Daox. Yea, i'm running 48 psi cold pressure in my tires and do basic hypermiling techniques... 62 on the interstate, short shifting below 2500 rpms, coasting, some engine shutting off on long coasts, minimize AC use etc. I have spend time over at cleanmpg.com but am looking for some possible changes i could do to the car to further aid me.

Thanks again,
Brandon

Hi Brandon - fellow Civic driver. I have a 2007 EX sedan. I saw potential in blocking the gap between the hood and the grille. I blocked that and the upper grille with styrofoam wrapped in duct tape. (I have a silver one - so that blended in quite nicely.) That improved my warm up time and on the freeway I say some improvement. Now that I drive in the city mostly I decided to go without either to maximize cooling.

I'm assuming you're still running on the OEM tires: Goodyear RS-A or Bridgestone EL400? I had the RS-A - which wore out very quickly - 17,000 miles and they were down to 4-6/32nds or so. Replaced them with Michelin MXV Primacy tires. They are quieter and much more comfortable. Mileage improved slightly. Now I run Bridgestone Turanzas. Excellent wet grip, but a little noisier than the Michelins. I also had Michelin Hydroedge tires on our previous car which were awesome in the rain and still very good in the dry. Not so good in slushy snow.

So what I'm saying is tires make a big difference on my car - maybe yours too.

I do not floor the gas pedal all the way and ease off the throttle as the rpms rise. That way I get better initial acceleration without forcing the ECU to shift away from the economy camshafts. Try shifting at around 2200 rpm so the rpms in the next gear start at 1500-1600.

Oh, and use engine braking am much as you can. I try to make the most of the free revving engine and "free miles" I get from the DFCO (see glossary). I usually downshift to 3rd gear from 60-70, and then 2nd at around 40-44 mph. I try to match the revs by blipping the throttle to minimize wear on the clutch and drivetrain.

My best mileage using the above techniques is 50. 45 mpg (best) when driving 55 and under on highway.

If you feel mod-happy consider turning the license plate bracket in the front around 180 degrees. It requires some cutting of the bracket, but it gives you more blocking of the grille (sorta) and cleans up the look in the front of your car. Thought about doing it when replacing the fog lights (that had chipped the lenses for the THIRD time... :( ), but I chickened out.

Oh, and consider modifying your route to reduce the number of stoplights. Sometimes driving further but not stopping can actually save you more gas. It avoids wasting the energy it took to get you up to speed in the first place.

Roland

For mods, try to make your car more like the Civic Hybrid. Those underbody panels, trunk lip spoiler, smooth (and light!) rims, etc.

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I disagree on using DFCO. I avoid it at all costs. You'll get better mileage by coasting in neutral. Even though the engine is using fuel at idle rate, the much extended rolling distance more than makes up for it.

I try to drive without ever using the brakes, and that includes DFCO which is engine braking. If you're braking, you are bleeding off excess speed. You burned gas earlier to generate that speed, and now you're wasting it. It's not completely possible to avoid the brakes, but if you're careful about it, you can avoid braking except at forced stops like stop signs. You can usually anticipate and time lights, to hit the green.

you are on the right track with upping the tire pressure.

i did a little test by blocking the upper grille and the SGII said i gained about 1MPG on at flat road going 60mph. but i took it off because it didnt look all that great...especially on a new car.

http://ecomodder.com/forum/showthrea...-log-6905.html

you could also lower your car if you are into that which will help mileage some.

i just bought the Civic hybrid engine belly pan, hope it helps some :)

Where did you get it, and how much was it?

Never thought about the interchangability of parts from HCH to regular Civic. Although the HCH wheels are more aerodynamic, lighter and skinnier. If you can find them cheap that may be a way to go too.

Maybe I should go to the dealer and take some photos of the underside of a HCH... :)

In defense of DFCO - I use it instead of braking. Makes me feel safer keeping all the power assists in rush hour traffic. It also keeps drivers behind me alert when I slow down without the brake lights going on. Tailgaters always seem to give me more room that way...

Except when coming to a stop. Then it is better to DFCO

Seen this?

I don't know if you guys know this but the 8th gen civic has a sweet spot for highway speeds. My mom has an automatic but when she drives 65mph the scanguage will show high 50's/low 60's MPG. Also if you're driving around 40mph and just depress the gas a little bit the car will go into 5th and stay there, howering at around 1300rpm.

For the manual civic I would use a scanguage and find out it's sweet spot for freeway cruising.