2006 Honda Insight MT Build Thread

[mpg_numbers_guy]

A few numbers from a shorter highway trip today (25.7 miles each way).

I was running too short on time to 55-mph-highway-hypermile my way to an interview this afternoon. Temps were in the 80s and it was sunny out. No wind.

• Cold engine, >90% load acceleration, 3K RPM upshifts, 5th gear cruising, target speed 55 MPH for 5.4 miles to the highway: 71.1 MPG indicated
• Engine now warm, highway cruising, target speed 70 MPH (65-74 MPH, DWL) for 19.9 miles: 85.3 MPG indicated at the exit ramp. 3.5K RPM upshifts, 5th gear cruising.
  • 5.4 miles / 71.1 MPG = 0.0760 gallons
  • ( 5.4 miles + 19.9 miles ) / 85.3 MPG = 0.2966 gallons.
  • 0.2966 - 0.0760 = 0.2206 gallons
  • 19.9 miles / 0.2206 gallons = 90.21 MPG
  This correlates to what I was seeing on the gauge - 85 MPG at 66-73 MPH, and 90-100 MPG at 66-73 MPH drafting behind trucks, 3-5 car lengths away. The car would kick out of lean burn at 73 MPH. 72 MPH was the max speed I could go where lean burn would immediately re-engage after a NOX purge. Going 73+ MPH would bring the MPG down to around 70-ish, although I never spent enough time there to verify; it could be closer to 65 or 75 MPG. From 72 to 73 MPH = 15 MPG loss due to no lean burn.
• Warm engine, 0.4 miles downtown to my destination, just before the rush so little traffic and things were times right. Trip finished at 84.8 MPG over 25.8 miles.
  • ( 5.4 miles + 19.9 miles ) / 85.3 MPG = 0.2966 gallons.
  • ( 5.4 miles + 19.9 miles + 0.4 miles ) / 84.8 MPG = 0.3031 gallons.
  • 0.3042 - 0.2978 = 0.0065 gallons
  • 0.4 miles / 0.0065 gallons = 61.54 MPG.

On my way home I had time to hypermile the same route. Unfortunately traffic was heavy until I got onto the highway, where overall slower speeds allowed me to drive slower despite the traffic and get better economy without being an a****** driver.

• Mostly cold engine, 0.4 miles from parking garage to highway, 44.1 MPG indicated.
  ^^ this is where a hybrid battery would help. This was pretty much just 1st gear to 6-8 MPH, then EOC for 20 feet until stopped again, rinse and repeat.
• Engine warm, highway cruising, target speed 55 MPH (50-59 MPH, DWL) for 19.9 miles, no drafting behind semis: 99.8 MPG indicated at the exit ramp. <2.5K RPM upshifts, 5th gear cruising.
  • 0.4 miles / 44.1 MPG = 0.0091 gallons
  • ( 0.4 miles + 19.9 miles ) / 99.8 MPG = 0.2034 gallons
  • 0.2034 - 0.0091 = 0.1943 gallons
  • 19.9 / 0.1943 gallons = 102.42 MPG
  This correlates to what I was seeing - 100-115 MPG cruising at 50-59 MPH on level ground, 120-135 MPG on slight downgrades, with 90-95 MPG up slight inclines. No major hills.
• Warm engine, 5.4 miles back home, one of my memorized roads for hypermiling, target speed 35 MPH (31-37 MPH), 5.4 miles from the highway back home. Final display on the FCD: 104.3 MPG. <2K RPM upshifts, 5th gear cruising.
  • ( 0.4 miles + 19.9 miles ) / 99.8 MPG = 0.2034 gallons
  • ( 0.4 miles + 19.9 miles + 5.4 miles ) / 104.3 MPG = 0.2464 gallons
  • 0.2464 - 0.2034 = 0.0430 gallons
  • 5.4 miles / 0.0430 gallons = 125.58 MPG.
  Those last 5.4 miles are pretty much what most of my non-delivery driving is on my drive to work and back, although the MPG is usually a little lower (100-120) due to starting off on a cold engine.

Warm engine - coolant temp between 202 and 207 F, and intake temp between 98 and 119 F.

Ambient temperature outside was in the 80s, no wind, pretty darn good day for fuel economy. I'm sure adverse weather would knock these numbers down, especially the numbers for my first run at higher speeds.

Looking forward to seeing how the Insight performs on my trip down to Virginia for college in a couple weeks, especially with the mountains on the last half (I-64, anyone? )

Over half the carpet is done in the rear of the car; I have a bunch of pictures but yawns it's late enough as it is and I have a busy day tomorrow, er, today. I'll post an update soon, possible Sunday evening. Maybe the carpet will be done by then.

[19bonestock88]

What day you gotta drive through WV?

[mpg_numbers_guy]

Originally Posted by 19bonestock88

What day you gotta drive through WV?

Current schedule is sometime late morning / early afternoon on the 18th through WV.

[mpg_numbers_guy]

Turns out that my kill switch for the Meanwell PSU malfunctioned, and was turning 10%-30% of the wattage into heat. Melted a little bit of foam, weakened my ground bolt so that it broke, and dropped my Meanwell charging voltage to <13v, if it was even charging. Also got a burn on my fingers due to touching the bolts before realizing how hot they were....after only a 6.5 mile trip into work.

The switch claimed to be rated for 12v 500a, and I don't even come close to a tenth of that. Ground connections were good, so my guess is that the switch malfunctioned inside, which messed up the connection of the input/output wires on the ground line, which caused it to overheat.

Flipped the kill switch off for my drive back home this afternoon so it wouldn't overheat again, and got 128.5 MPG over the 6.5 miles with the meanwell off, a new record trip. Having the meanwell off definitely does improve economy, but I see no way of driving without it for longer periods of time other than by spending $$$ on batteries....and I removed the IMA battery to avoid that.

Got rid of the kill switch, drilled a new ground hole, and everything's working alright again. Don't want to add a relay to 12V since that seems overly complicated, as well as a reduction in efficiency by around 8W wasted on the relay.

I read on IC that the Meanwell unit has a 100mA parasitic drain, so as long as the car isn't parked for a while I should be fine. I drive the car about 5 days a week during the summer, and when it sits at college I'll just pull the battery cable.

[mpg_numbers_guy]

All I have left to do on the carpet is
- Spare tire box lid
- Lid for meanwell storage spot
- Back board behind driver's seat

I really haven't had time to post an update with pics, so I'll probably end up posting one huge post with details when it's done. I promise I've been taking pictures though!

Got a LED flasher relay and LED turn signals installed in the rear; will install front ones when I rotate my tires. Going from 21W to 3W per bulb should eliminate the meanwell fan pulsing as well as the meanwell shutting off at low RPM when I turn the signals on due to an additional 2x21/12 = 3.5 amp draw, that will now be reduced to about half an amp.

[19bonestock88]

Nice work! That reminds me that at some point I need to consider some LED bulbs other than my DRLs

[California98Civic]

Originally Posted by mpg_numbers_guy

... Got a LED flasher relay and LED turn signals installed in the rear; will install front ones when I rotate my tires. Going from 21W to 3W per bulb should eliminate the meanwell fan pulsing as well as the meanwell shutting off at low RPM when I turn the signals on due to an additional 2x21/12 = 3.5 amp draw, that will now be reduced to about half an amp.

This is interesting. I have read that the relay and such can make replacing flasher bulbs with LEDs not worth it... that the power benefits are reduced because of the relay. But this is a significant savings. What relay did you buy?

[mpg_numbers_guy]

You may be confusing a LED flasher relay with resistors.

An "easy" fix to installing LED turn signals without hyperflashing is to install resistors in the turn signal wiring to increase the current draw, which makes the stock thermal flasher think that regular bulbs are in place and flashes normally. The downside there is that the resistor heats up VERY fast, and depending on where you have it mounted could damage exterior paint from the heat and/or be a fire hazard. After all, in order to pull 0.3 amps up to 2 amps means that 1.7 amps are being wasted as resistive heat whenever the turn signals are on.

If I remember correctly, the electronic flasher relay uses some sort of timer for the turn signals. Both LEDs and halogens blink at the same rate.

I opted to go with the flasher relay so I would actually benefit from the reduced electrical draw and not have to deal with all that wasted heat. I'm sure the relay wastes some energy as heat, but then again, so did the stock thermal flasher relay, and turn signals don't work without a relay.

Turn signals really aren't on all that much, so there really isn't any benefit unless you do a lot of driving without an alternator, but due to how the Meanwell pseudo-alternator works on the Insight, I can be driving along at, say, 1000 RPM with the battery charging and supporting base load + headlights just fine, but then have the turn signals on to make a turn and just have enough of a current draw to barely shut off the Meanwell at those low RPMs, and then have to be at 1200 or so RPM for ~5 seconds for it to turn back on again. Or if it does stay on, then the fan pulses in sync with the turn signals. The first sentence of that paragraph is too long, but I am too tired to fix it tonight lol.

With just the rears installed this seems to be mostly fixed; hopefully I see it work even better when I have the fronts installed.

I just went with a $8 C13/EP34 flasher relay from Amazon. Not sure if all Honda's have the same kind of relay; I would double check first before buying one. LEDs were $19 for 4. Not expecting any ROI other than the Meanwell staying on at ultra-low RPM when turn signals/hazards are on.

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I think I have a bad habit of using too many words just to answer one question.

[Ecky]

I considered doing the very same thing. My Mean Well was nearly silent with my dual 90mm fan setup but it was interesting to me that the turn signals alone could rev the fans up more than just about anything else in the car. Really puts in perspective how much energy they use.

Ultimately I didn't, because they're on for such little time.

[19bonestock88]

Lucky you, I’ve no way to correct my hyperflash from doing LED front signal bulbs, but the bulbs when used as the DRL would melt the bulb sockets when I had standard bulbs... the LEDs haven’t given me any trouble whatsoever since their installation (hyperflash aside)