HCH1 Ecomodding

[Ecky]

Hey all! You might have seen my other thread regarding my Insight. It looks like it'll be a little time before I get it back on the road, and we needed a vehicle for getting to and from work, so I picked up a fairly clean (for a northern car) 2004 HCH1. We were going to need a second vehicle soon anyway, and I thought it unwise to have two vehicles without backseats, despite how tempting it would be to get a second G1 Insight.








The first time I took it down our dirt (or rather, mud) road it quit sparkling in the sun. It has clearly been well maintained, but 12 years of salt has left its marks. There's a fair amount of surface rust on engine components, and the catalyst head shield is practically crumbling. The rear quarter panels are just starting to show signs of rust damage, but everything seems mechanically sound, the hybrid battery is healthy, and it has low (124k) miles.

On the way home I averaged around 40mpg on the highway (65mph), and ~50mpg on the 50mph 25-mile stretch to my house in ~10f/-10c weather through slush and snow. 50mpg in a vehicle this size was already pleasing to me, but after arriving home I found that the tires were seriously low on air - the fronts were both at 22, one rear was at 30, and the other, at 10psi. After bringing them up to 44 where they should be:




Close to 60mpg at 50mph, with nothing but air in the tires! And, around 50mpg at 65mph, with the outside air temperature hovering around 0f.


I put my first mod on today, as it seems to struggle to maintain temperature when I have the heat running and it's significantly below freezing:




When I have some time, I'd like to get some side skirts for the rear wheels, and a proper belly pan installed. I'd also like to treat some of the rust spots, get a grid charging harness built for the hybrid battery.

I'm excited to see where it'll be once things warm up and I get a proper set of LRR all-season tires on it.

[Ecky]

My impressions:

Driving the HCH1 feels like driving a barge when compared with the Insight. It weighs almost 50% more (2732lbs vs 1878lbs), and the inferior power steering implementation does NOT help. The steering feels fine at low speeds, but once above ~20mph the amount of assist delivered is reduced, resulting in very heavy steering. Power output is 93HP @ 5700RPM and 87ftlbs @ 1500RPM, compared with 73HP @ 5700RPM and 91ftlbs @ 2000RPM in the Insight. It doesn't feel slow, however, and whatever the difference in torque curve is on the two cars results in the Civic needing far less downshifting to climb hills, despite having an inferior power to weight ratio. It's very easy to keep the car below 2000RPM even when climbing fairly steep hills.

I think I like the transmission better in the HCH1 though. Shifting is smoother, and the gearbox feels more "solid", less "tinny". Both have similar RPM in 5th gear - something like 2000RPM at 65mph, which is very attractive. The Insight's gearbox has a lot of space between gears 1, 2 and 3, and 3, 4 and 5 are much closer together; They're nearly linear in the HCH1.

Sound insulation is much better, and the low Cd (0.28 stock) contributes to very quiet highway cruising. The Insight is not loud by any means, but the aluminum chassis seems to transmit more sound.

The HCH1 coasts extremely well, a result of its low drag and relatively high weight, and has a neat trick when coasting in neutral - when rolling in neutral, the hybrid battery begins charging with 4 bars of regen after a few seconds. My reading suggests that when coasting in gear, it closes the valves in the engine, and the IMA can soak up more power, overall resulting in it being easier to keep the hybrid battery up.

My initial impression of the seats is more positive than of the Insight's, though they're still not great.

I can't decide if I prefer the digital readout and buttons in the Insight, or the traditional dials and knobs in the HCH1. Both are attractive to me.

The HCH1 has cruise control from the factory, and it works better than the Rostra system I installed in my Insight.

The factory speakers are not nearly as awful as the Insight's, though I've significantly upgraded the sound in my G1, resulting in the Civic having an inferior sound system.

Overall, I'm quite happy with the car. I'm willing to bet I can hit 70mpg or more when cruising at 50mph once the weather warms up and I get LRR tires on it.

[vskid3]

I was wondering when you were going to say that the tires were low. I knew it should get better mileage; my '97 Civic DX would get about the same as you got with the low PSI.

Looks like a nice car. I wish the Civic Hybrid had come in a 4-door hatch or wagon, then I could have a manual tranny hybrid and cargo capacity instead of my Prius.

[Ecky]

I'd prefer a wagon or hatch too, but there weren't any comparable Prii anywhere near the price and condition of this car and I don't know offhand of any hatches or wagons, other than a Prius, with comparable potential.

Forgot to mention, I'm inclined to believe I'm not getting lean burn. Over on IC they've said the transition to LB is more subtle than in the Insight, but I'm fairly certain I'd be able to recognize it on the FCD. I might replace the EGR valve and clean the passages to see if it helps, but time and weather are not permitting right now.

[Baltothewolf]

HCH1's LB doesn't suck as much power for some reason, maybe it doesn't lean out as much? Idk. I just remember driving a HCH1 at one point and it was very difficult to tell that I was in LB at all. MPG's don't jump up as much, nor does the power dropoff feel the same.

50mpg @ 70mph should be achievable in an HCH1 with LRR tires and proper foot control.

[Ecky]

Originally Posted by Baltothewolf

HCH1's LB doesn't suck as much power for some reason, maybe it doesn't lean out as much? Idk. I just remember driving a HCH1 at one point and it was very difficult to tell that I was in LB at all. MPG's don't jump up as much, nor does the power dropoff feel the same.

50mpg @ 70mph should be achievable in an HCH1 with LRR tires and proper foot control.

There aren't any 70mph roads anywhere near here.

50mph followed by ~60mph are probably more two most common speeds.

EDIT: Looking at LRR summer (all season) tires:

TireRack has Michelin Defenders available for the factory size of 185/70r14 for ~$100 each

Walmart has Goodyear Integrity tires in 185/70r14 for ~$70

A brief google search reveals that the Defenders are all-around better tires, but I'm primarily concerned with rolling resistance, and they will not be used in winter weather. Anyone have experience with either of these, or know of any other better tires in a similar size?

[Daox]

The Integrity is the 2nd gen Prius OEM tire. Its not known for grip, but its RR is decent. For the $30 discount per tire I'd probably go with them.

[cowmeat]

I don't know how much difference there is between Michelin Defenders and Michelin Energy Savers - but for what it's worth I absolutely loved the Energy Savers that are on my first Insight. They look no different now than when I bought the car, and neither my son or I have any complaints as far as drive-ability. The car has at least 15,000 more miles on it now and I can't tell any difference in the tires.

I pull the same mpg driving Turtle as I do in Ron Burgundy, which has the Potenzas on it, so there's not really an mpg hit with the Michelins.

[Baltothewolf]

Michelin defenders are the go to tire when energy savers/potenzas are not an option. My bro gained like 3mpg in his crown Victoria back when he had it, and went from Falken tires to defenders. He said it also was much quieter and smoother of a ride.

[Ecky]

Anybody know what the correct thermostat for this car is? I have every indication that the thermostat is functioning correctly, but it warms up to ~86c (187f?), whereas my Insight warms up to 90c/195f. Is this correct?

Also, I've noticed that the radiator fan frequently stays on for 30-60 seconds after I park the car and turn off the engine, despite coolant temperatures being ~86c when I park it. Before I checked temps with my bluetooth dongle, I was thinking the lower grille block might've been too much.