Sleek WILL break 40mpg!

[westb87]

I just filled up this morning and I've gone from my first tank average of 33mpg to my new highest average of 38.5mpg! I've been suspecting my SGII was off and that's why I was seeing my feedback on the unit so low...for example, it was telling me that I was averaging 32-35mpg cruising at 45mph...lol. The SGII (this is the second fillup) was off by over 50%! It thought I had munched through 20.99 gallons of gas in my little Civic that has a 12.3 gallon gas tank.

I'm going to break that 40 mark guys, I promise. I still haven't removed the mudflaps or done any grille blocking. I've got a family vacation to San Antonio coming up in the next few weeks, so it may be a while before I get around to throwing my eco-mods on the car. My plan though, is to remove side mirrors (keeping the interior rear view is legal in Alabama), remove mudflaps, block upper grille, block 50% of lower grille, lawn edging air dam, and an aluminum sheeting underbelly pan. As I progress, I'll keep everyone up to date!

[mpg_numbers_guy]

Way to go! I see 40+ coming here in the near future!!

[elhigh]

That's a big improvement.

Any mods you make before you set out will provide a quieter, smoother ride. Not joking: air turbulence is noise and buffeting. Do some testing before committing to a long trip with grille blocks of course.

[westb87]

Originally Posted by elhigh

That's a big improvement.

Any mods you make before you set out will provide a quieter, smoother ride. Not joking: air turbulence is noise and buffeting. Do some testing before committing to a long trip with grille blocks of course.

Thanks!

The Civic is really just the "in-town commute" car. I wish it could fit our family during a road trip though, it'd be awesome.
We are taking "Broomstick", our VW Atlas, instead since we have to bring our dogs. I'm going to try some blocking on it and will monitor the oil temps during the trip. I plan to have blocking that's removable in sections so, if needed, I can remove pieces to allow the car to cool more. It's a big, burly SUV that could probably benefit from some aero-mods. I'm going to try to fold the mirrors in as well to see if it helps with the MPGs. We are excited!

[mpg_numbers_guy]

Originally Posted by elhigh

Any mods you make before you set out will provide a quieter, smoother ride. Not joking: air turbulence is noise and buffeting.

Except for inflating your tires to sidewall max.

[westb87]

Ok ok ok, so I know I said that any mods to the Civic may take time, but I geeked out a bit yesterday and mocked up some grille blocking. I'll preface the rest of this post with the fact that I got an extra 2.6mpg out of my morning commute today than I did yesterday's morning commute. An improvement from 41mpg to 43.6mpg AND I got hung up at 4 more red lights than I normally do.

I didn't take any pictures yet because most of the work is just in cardboard mockup. However, for the upper grille I got a bit creative. At first, I was just going to duct tape the upper grille and then paint the duct tape black. Then I had a creative idea! I'm a big fan of spray foam and polyiso insulation and for spray foam, I use one of the "pro-guns" that the larger cans of spray foam screw to. They give you much better control than the standard straw. So I removed my upper grille, duct taped the face of it as flat and even as I could, flipped it over and filled each of the little honeycomb shapes in with spray foam. Once the foam cures, I'll remove the duct tape, shave the foam flat at the face and spray paint it black. That way, the upper grille will still look as stock as possible while also acting as a grille block. I'll take some pics when it's back on and purdy.

For the lower grille, I've mocked up some cardboard and secured it with zip ties. The opening was maybe 6" across. This morning was about 65 degrees and the car hit 204 (my car's fan trigger temp) about halfway through my commute, would drop to about 197 and rise again, but wouldn't go above 207 as long as I was cruising. This is warmer than I care for...considering these Civics are prone to warping heads in high heat. I couldn't hear it, but I assume that those temperature swings were the result of the fans cycling. When I got to work, I opened about 4" more of opening each way (for a total of about 8" more total opening) because it's going to be damn near 90 degrees on the way home. Once I determine an opening that will survive an Alabama summer, I'll build some permanent polyiso insulation blocks, paint them, and secure them in with a "staged" block system that will allow me to add and remove sections of the "safe" opening to keep pace with the weather...most likely with industrial grade Velcro so I'm not screwing with zip ties all the time.

I'm going to run this grille block setup for this tank so I can see how much of an effect it has across an entire tank. After I determine it's effect over this tank, my next mod to "test" is the lawn edging air dam. It'll get run down through a whole tank as well. Thanks for reading!

[westb87]

I took the mudflaps off yesterday because the two front ones were dangling enough to look unsightly and I figured they weren't helping my mileage.

On my way in to work this morning I got an average of 47mpg! That's a jump from 43.6mpg earned during yesterday's commute. Could those mudflaps really have been parachuting the car THAT much?! My instant MPG readout at 50mph hovered around 60-65mpg and my readout at 60mph was around 42-50mpg. The car's temp was hovering around 204-207 degrees, which is still warmer than I'd like. When it hit 207, I'd hit the A/C button (I was just running the fan on the lowest setting otherwise) and let it cycle down to about 195 before I'd cut it off again. I assume that running the AC (and it's obligate running of the e-fans) yesterday afternoon is what kept the car cooler during my commute home.

[19bonestock88]

Nice work! Looking forward to seeing your grille blocking take shape! Hadn’t thought of using foam... I use strapping tape because I get it for free and have a huge surplus lol

[westb87]

Originally Posted by 19bonestock88

Nice work! Looking forward to seeing your grille blocking take shape! Hadn’t thought of using foam... I use strapping tape because I get it for free and have a huge surplus lol

Hey man, I'm all about saving money and using what you've got on hand! Foam just happened to be my "surplus" supply and I wanted to see if I could get crafty with it. I've used "window & door" foam on the inside of the body around the rear wheel well cavity (coupe) as sound dampener. Nearly my entire cavity in front of and above each wheel well is filled with foam. Having done that, now the only road noise I hear is from the front wheel well areas. I'm a fan of "light and effective"

[mpg_numbers_guy]

Originally Posted by westb87

Ok ok ok, so I know I said that any mods to the Civic may take time, but I geeked out a bit yesterday...

Now you sound like me lol

Originally Posted by westb87

...and mocked up some grille blocking. I'll preface the rest of this post with the fact that I got an extra 2.6mpg out of my morning commute today than I did yesterday's morning commute. An improvement from 41mpg to 43.6mpg AND I got hung up at 4 more red lights than I normally do.

How long is your commute? My grille blocking (upper and lower) was good for a tested 1 mpg improvement.

Originally Posted by westb87

I didn't take any pictures yet because most of the work is just in cardboard mockup. However, for the upper grille I got a bit creative. At first, I was just going to duct tape the upper grille and then paint the duct tape black. Then I had a creative idea! I'm a big fan of spray foam and polyiso insulation and for spray foam, I use one of the "pro-guns" that the larger cans of spray foam screw to. They give you much better control than the standard straw. So I removed my upper grille, duct taped the face of it as flat and even as I could, flipped it over and filled each of the little honeycomb shapes in with spray foam. Once the foam cures, I'll remove the duct tape, shave the foam flat at the face and spray paint it black. That way, the upper grille will still look as stock as possible while also acting as a grille block. I'll take some pics when it's back on and purdy.

Good idea with the foam! The 7th gen Civic's upper grille is somewhat tricky to fab up a grille block onto since the backing isn't flat and flush like most others are.

I want pics!

Originally Posted by westb87

For the lower grille, I've mocked up some cardboard and secured it with zip ties. The opening was maybe 6" across. This morning was about 65 degrees and the car hit 204 (my car's fan trigger temp) about halfway through my commute, would drop to about 197 and rise again, but wouldn't go above 207 as long as I was cruising. This is warmer than I care for...considering these Civics are prone to warping heads in high heat. I couldn't hear it, but I assume that those temperature swings were the result of the fans cycling. When I got to work, I opened about 4" more of opening each way (for a total of about 8" more total opening) because it's going to be damn near 90 degrees on the way home. Once I determine an opening that will survive an Alabama summer, I'll build some permanent polyiso insulation blocks, paint them, and secure them in with a "staged" block system that will allow me to add and remove sections of the "safe" opening to keep pace with the weather...most likely with industrial grade Velcro so I'm not screwing with zip ties all the time.

Did you cover the fog light opening areas with the lower grille block at all?

Originally Posted by westb87

I'm going to run this grille block setup for this tank so I can see how much of an effect it has across an entire tank. After I determine it's effect over this tank, my next mod to "test" is the lawn edging air dam. It'll get run down through a whole tank as well. Thanks for reading!

Lawn edging air dam - single best mod outside of a boattail. Worth the entire $5 for the lawn edging!

Originally Posted by westb87

I took the mudflaps off yesterday because the two front ones were dangling enough to look unsightly and I figured they weren't helping my mileage.

You...had...mudflaps...on...your...car? Terrible!

Originally Posted by westb87

On my way in to work this morning I got an average of 47mpg! That's a jump from 43.6mpg earned during yesterday's commute. Could those mudflaps really have been parachuting the car THAT much?! My instant MPG readout at 50mph hovered around 60-65mpg and my readout at 60mph was around 42-50mpg. The car's temp was hovering around 204-207 degrees, which is still warmer than I'd like. When it hit 207, I'd hit the A/C button (I was just running the fan on the lowest setting otherwise) and let it cycle down to about 195 before I'd cut it off again. I assume that running the AC (and it's obligate running of the e-fans) yesterday afternoon is what kept the car cooler during my commute home.

Looking good! But what's AC?

Trips can vary by quite a bit, so one can't say for sure exactly how much of an improvement is there unless you do ABA testing. But is a generally accepted thing that mudflaps add drag and reduce FE, albeit on a smaller scale.

You might find that if you can properly install wheel spats and boattail behind the mudflaps that they might provide a good mounting surface for wheel skirts, and actually increase your FE.

Originally Posted by westb87

...I've used "window & door" foam on the inside of the body around the rear wheel well cavity (coupe) as sound dampener. Nearly my entire cavity in front of and above each wheel well is filled with foam. Having done that, now the only road noise I hear is from the front wheel well areas. I'm a fan of "light and effective"

Pics??