2002 Honda Civic Coupe LX 5spd Build Thread

[mpg_numbers_guy]

Originally Posted by Christian

Wow, that's a huge increase, I am tempted to do some EOC, but I have a lot of hills and traffic on my short trips. I'm worried about the loss of brake assist more than the loss of power steering, but I will keep this in mind when on empty side streets. Recently, I have been doing much more coasting in neutral, which I believe has helped in my improved fuel economy. It's hard to confirm though, as the road conditions and outside temperature have improved so much.

Only EOC on roads you're familiar with, do it in neutral first and make sure you can coast the distance with few or no applications of the brake before doing EOC on it, just to be safe. On highway EOC doesn't make that much of a difference, but it makes a huge difference around town and idling in heavy traffic.

Originally Posted by Christian

I'm only doing 35psi, as my winter tires are recommended for 30psi, but once the weather improves and I can put my new lightweight wheels and tires on, I'll definitely be running higher pressure.

What winter tires are you using, out of curiosity? Most of the ones I've seen are rated for 44 or 51 PSI. I won't speak of the tire pressures I've run or still run.

Originally Posted by Christian

I have recently acquired 4 medium-sized coroplast signs, so the next item on my list will be making a grille block. I'm thinking I'll start with a full upper grille block and eventually a ~30% lower grille block. I need to find some vinyl wrap though, because the signs are bright yellow...

Use a Scangauge or Torque app to monitor actual coolant temps when you start blocking off the grille, don't rely solely on the dummy gauge in the gauge cluster.

[Xist]

You can wire an LED under your cowl to light up when your fan turns on. You might see improved fuel economy with 100% fan utilization, but what would your car do when it gets warmer than that?

[Christian]

Originally Posted by mpg_numbers_guy

Only EOC on roads you're familiar with, do it in neutral first and make sure you can coast the distance with few or no applications of the brake before doing EOC on it, just to be safe. On highway EOC doesn't make that much of a difference, but it makes a huge difference around town and idling in heavy traffic.

Thanks, will do. My commute to school is less than 2km (1.25mi), and almost all stop and go on a steep hill. So it really makes it difficult to find much room for coasting especially with the engine off. Lately, however, I've been taking side streets which allow me to p&g a tiny bit, but still difficult due to all the stop signs every block.

Originally Posted by mpg_numbers_guy

What winter tires are you using, out of curiosity? Most of the ones I've seen are rated for 44 or 51 PSI. I won't speak of the tire pressures I've run or still run.

BFGOODRICH Winter Slalom P185/60/R15. I just double-checked and the max pressure is 44psi. For some reason I had it in my notes that I couldn't fill over 35.

Originally Posted by mpg_numbers_guy

Use a Scangauge or Torque app to monitor actual coolant temps when you start blocking off the grille, don't rely solely on the dummy gauge in the gauge cluster.

I will, I have a SGII and just built a 60% grille block prototype. I'm going to be posting some pics within the next hour or so.

[Christian]

This is much sooner than I anticipated considering update #4 was 3 days ago, but here's an update as I had some free time today.

As mentioned in previous updates, I've been planning on doing a full upper grille block, and a partial lower grille block, but had yet to buy any coroplast. Luckily, about 2 weeks ago I saw some free coroplast signs on Facebook marketplace and obviously I had to grab them. They're bright yellow, but they were free... pros and cons I guess.

Today started off on a crummy note, I woke up to a nail in my tire AND it was snowing. When I brought my car it in to get the tire plugged, the sidewall was bulging, so it had to be replaced. The tire shop wanted $228 ($171 USD) for a new tire, which was laughable considering I spent $200 ($150 USD) on my 4 winter tires and rims. Luckily there was a cheap shop nearby, and I got a $70 ($52.59 USD) used tire.

On the bright side, I was free today, and the cold/snow this morning reminded me that my fuel economy would inevitably start decreasing. So, I decided to take measurements and build a prototype for my partial lower grille block outside in the cold like a crazy person. All went well, and I had a good cardboard prototype, so I decided to just go ahead and build my coroplast version, which went well. I haven't put it on the car yet, as it is currently drying because I had to paint it black, but I will fit it soon.

Specs: 17in x 4in - Partial block of exactly 60.714% of the lower grille.

Attached are some images of the rough prototype grille block. Will post photos of the painted coroplast version once it is dry and I've fitted it.
(Full disclosure: the final version is 1in longer than the prototype pictured, this was done to add a third mounting/zip tie spot.)

[Ecky]

For reference, this is the grille block I ran in Florida during summer:

[Christian]

Originally Posted by Ecky

For reference, this is the grille block I ran in Florida during summer

I likely could run a full lower grille block, but don't want to deal with the hassle of removing it if I'm doing long drives in the summer. I will keep an eye on the water temperature and adjust accordingly though.

Your pipe insulation lower block looks great, I was planning on doing the same since it allows for easy removability, but I prefer the flush look of coroplast.

Your taste in cars is great, I have been in the market for a clean miata for years, and I really like insights, and you've owned both!

[EcoCivic]

-I haven't had any luck with EOC for my driving style despite trying it several times. About the best it *might* have done for me over letting the engine idle while coasting was increase my tank average from 47 MPG to 48 MPG, but due to variances in weather, that 1 MPG gain isn't even directly attributable to EOC. For me, the possible tiny gain isn't worth the hassle, safety risks, extra wear on the engine and entire drivetrain from constant bump starting, etc, but YMMV.

I'd personally bock the grill as much as I can get away with plus a decent safety margin in the winter and not block it at all in the summer if you are using AC regardless of engine temps. I would think the decreased AC efficiency and longer compressor cycles from the condenser not cooling as efficiently has a good chance of negating any aerodynamic benefits and will cause unnecessary stress on the AC system. But if you won't be using AC, this part isn't a concern.

You don't want the fans running excessively from the grill block either, this will cut into your savings since the engine to fan motor efficiency will be ridiculously low due to the ~50% alternator efficiency and ~75% efficiency of the fan motors. Both fans together draw around 16 amps, which is ~224 watts. When factoring in alternator efficiency, running the fans is about an extra 2/3 HP of load on the engine.

The fans on these cars are no fun to change either, so I wouldn't take the extra wear on the fan motors too lightly.

[Christian]

Originally Posted by EcoCivic

-I haven't had any luck with EOC for my driving style despite trying it several times. About the best it *might* have done for me over letting the engine idle while coasting was increase my tank average from 47 MPG to 48 MPG, but due to variances in weather, that 1 MPG gain isn't even directly attributable to EOC. For me, the possible tiny gain isn't worth the hassle, safety risks, extra wear on the engine and entire drivetrain from constant bump starting, etc, but YMMV.

I'd personally bock the grill as much as I can get away with plus a decent safety margin in the winter and not block it at all in the summer if you are using AC regardless of engine temps. I would think the decreased AC efficiency and longer compressor cycles from the condenser not cooling as efficiently has a good chance of negating any aerodynamic benefits and will cause unnecessary stress on the AC system. But if you won't be using AC, this part isn't a concern.

You don't want the fans running excessively from the grill block either, this will cut into your savings since the engine to fan motor efficiency will be ridiculously low due to the ~50% alternator efficiency and ~75% efficiency of the fan motors. Both fans together draw around 16 amps, which is ~224 watts. When factoring in alternator efficiency, running the fans is about an extra 2/3 HP of load on the engine.

The fans on these cars are no fun to change either, so I wouldn't take the extra wear on the fan motors too lightly.

Thanks for the heads up, 47-48mpg would be amazing for me, but since I'm almost exclusively short city drives, I feel that EOC would be a great method to squeeze extra efficiency out of my civic. I really want to wire a killswitch to the injectors, because I would love to have my SGII stay on while the car is off, and I hate fiddling with the key and having my radio shut off.

My civic sits right around 193-197 degrees Fahrenheit when warmed up and driving around. I will definitely need to figure out at which temperature my fans turn on, in order to ensure my fuel economy & fan efficiency don't counteract. Hopefully, I won't need to worry too much, as our weather isn't great most of the year, and I rarely run A/C.

Originally Posted by Xist

You can wire an LED under your cowl to light up when your fan turns on. You might see improved fuel economy with 100% fan utilization, but what would your car do when it gets warmer than that?

This is a great idea, I saw mention of this in another thread, and it definitely would be helpful to be able to watch my fans so precisely. Who knows if I end up doing it though, as mentioned, I hate messing with wires.

[EcoCivic]

Originally Posted by Christian

Thanks for the heads up, 47-48mpg would be amazing for me, but since I'm almost exclusively short city drives, I feel that EOC would be a great method to squeeze extra efficiency out of my civic. I really want to wire a killswitch to the injectors, because I hate fiddling with the key and having my radio shut off.

My civic sits right around 193-197 degrees Fahrenheit when warmed up and driving around. I will definitely need to figure out at which temperature my fans turn on, in order to ensure my fuel economy & fan efficiency don't counteract. Hopefully, I won't need to worry too much, as our weather isn't great most of the year, and I rarely run A/C.



This is a great idea, I saw mention of this in another thread, and it definitely would be helpful to be able to watch my fans so precisely. Who knows if I end up doing it though, as mentioned, I hate messing with wires.

A killswitch would be a good idea if you plan on killing the engine regularly, it's much easier and safer than messing with the key and would save substantial wear on the ignition switch in the long run. But first, I would do some testing to see if killing the engine rather than letting it idle is significantly beneficial for your driving style. For what it's worth, when I tried EOC, I saw a slight drop in my average MPG if I killed the engine when it was still cold, presumably because doing so significantly delayed warmup. By a narrow margin, I seemed to get the best results with EOC by killing the engine only after the coolant was fully warm, but we're talking about +/- about 1-2 MPG, so easily within testing variance.

193-197 degrees coolant temp is about 10 degrees hotter than I see with an OEM thermostat, but still perfectly fine. Perhaps someone installed a hotter thermostat. The OEM fan switch is supposed to activate at 93 degrees C (~199 degrees F) according to the service manual, but since the fan switch is on the thermostat housing and sees cooled return coolant while the temp sensor sees hot supply coolant, that seems to translate to the fans activating at about 204 degrees F indicated coolant temp on my car. So as long as you aren't seeing 200+ degrees, the fans shouldn't be on.

[Christian]

Originally Posted by EcoCivic

A killswitch would be a good idea if you plan on killing the engine regularly, it's much easier and safer than messing with the key and would save substantial wear on the ignition switch in the long run. But first, I would do some testing to see if killing the engine rather than letting it idle is significantly beneficial for your driving style. For what it's worth, when I tried EOC, I saw a slight drop in my average MPG if I killed the engine when it was still cold, presumably because doing so significantly delayed warmup. By a narrow margin, I seemed to get the best results with EOC by killing the engine only after the coolant was fully warm, but we're talking about +/- about 1-2 MPG, so easily within testing variance.

193-197 degrees coolant temp is about 10 degrees hotter than I see with an OEM thermostat, but still perfectly fine. Perhaps someone installed a hotter thermostat. The OEM fan switch is supposed to activate at 93 degrees C (~199 degrees F) according to the service manual, but since the fan switch is on the thermostat housing and sees cooled return coolant while the temp sensor sees hot supply coolant, that seems to translate to the fans activating at about 204 degrees F indicated coolant temp on my car. So as long as you aren't seeing 200+ degrees, the fans shouldn't be on.

I sincerely appreciate all this info! That's great to hear that the fan doesn't turn on until ~200+ degrees, I don't think I've even seen the car go past 200 more than a handful of times due to how short my trips are.

I believe an EOC kill switch would definitely be an improvement for me, as my average coasting speed in neutral is at max 30-40kph (19-25mph). Neutral coasting typically results in an indicated 5-8L/100km (47-29mpg) on my SGII. My engine usually doesn't even get fully warmed up on my short trips, so I don't think it will negatively impact that aspect of my efficiency.

IF I end up doing a kill switch, I also worry about the degradation of the wires/electronics over time, potentially causing issues starting or issues with the immobilizer.

It's frustrating because there is only so much efficiency I can squeeze out of this car while doing such short inefficient trips. It would be nice to get 7.8L/100km (30mpg) in the city, hopefully, I can achieve that once the weather improves.