Better economy for 8th Gen Civic Hybrid?
 

Picked up a Honda Civic Hybrid 2008 last month. $6300 after dealers fees and tax. Bought it for Uber... makes sense when you consider I can use it for 5 years and probably make $40k more than I would have without it, and I figure the mpg savings will help the car pay for a least half its costs while it's still rideshare qualifying. I would have got a Prius instead but the Prius was very uncomfortable to drive for long periods. The Civic seat is still kind of high and I find its accelerator much more difficult to reach than on my Corolla beater but it was the lesser of the evils.

So far I'm getting 40 mpg. Read all the papers about hybrid technology and the CleanMPG hypermiling doc. In practice the mpg gauge is difficult to exploit... it won't let me "feather" the pedal... maybe my foot is just too harsh, or maybe it just doesn't care when it gets a good charge and likes to go into full electric on straighaways and downhills, no matter the speed. Here in southwest Ohio most of the roads are interrupted by stop signs and traffic lights every mile or so... cars are now in a constant state of acceleration even in the space between suburbs. Costs lots of extra fuel but what can you do?

I've noticed I get 38 mpg at the low end and 42 at the high. Running the air conditioner on a couple hot days can knock 4 mpg off the tank. I run it conservatively, at 75 degrees ambient. When I got the car it was set to run at 70 and that really retarded the mileage. The a/c also kills the motor assist, making it a struggle to get up small hills and acceleration more gradual and expensive. I figure I can do with a decently powered dash fan on most days, so I'm going to buy one for the USB plug I use for my phone. Neither of the two have any power demands worth reckoning or noticing, compared to the a/c. I saw a 2-in-1 fan solution on Amazon but I'm not certain it will actually fit to the dash. Will need to use adhesive, probably, to get it to stick.

My first order of business was to get low rolling resist tires. I saw a good review on Tire Rack for Hankook Kinergy PTs, so I replaced the EP422s the car had been sold with. At the time I thought the Kinergy's, but after reading the Tire Rack testing methodology further, I'm not so sure because it seems different cars were used for both tests. I did some in-depth googling, binging and yahooing and was able to find some academic research papers on LRR tires, the most notable of which was by U of Michigan for Consumer Reports. It found that LRR tires sold in recent years actually have more rolling resistance than those sold in the 2ks, so the same cars will get less mpg today on account by at least a half mile. LRR tires in general apparently aren't that big a deal economy-wise... the same paper found that the difference between LRR tires and the worst winter tires, in terms of average fuel economy, was a sweet 1 mpg. Oh well, at the least the treadwear warranty is long.

I've heard of people getting 50 mpg from this car, and while the roads around here might not allow it, I'd like to try. Would at least like to get high 40s on the highway going 65. I do apparently sometimes, when it's straight or downhill and the car is able to go into pseudo-electric for minutes at a time. The main thing the car is good at is lowering RPMs... the thing it's not good at is keeping them down when accelerating. It also is able to shut its engine at a light (sometimes) which is something the Corolla could not do. The car tries to do all the thinking for the driver, instead of allowing the driver to choose how to use the battery most efficiently, so it will do things like waste out its charge sitting at red lights in series, and then struggle up a hill shortly thereafter resulting in a loss compared to if it had just ran the engine at the lights. Of course if you hit the break three times you can keep it running when stopped, so it's more like an "expert" car than anything. The cruise control is useless... at first I was glad to have it, but the car's tiny engine struggles so much with accel that it's a waste of money to use. I wonder if the car's efficiency is actually a matter of it having little power, so that it's able to force the driver to avoid waste. :turtle:

Considering some aero mods, then.


The wheels are more or less disc. Moon caps likely wouldn't improve their aero significantly, if at all. The back tires might benefit from wheel skirts.

Removed the spare tire kit already. The curb weight of the vehicle is 2750lbs plus the occupants. The front and back bumpers are apparently plastic. The doors are steel for obvious reasons. The unibody and fenders are steel to protect the frame. Carbon fiber paneling is likely uneconomical... likely the frame/chassis itself is the main weight culprit.

There is a rubber scrape guard which isn't much of an air dam. Might be able to use trimming or something to make a dam here.

The below door paneling is exposed to salt. This is where rust normally happens here. Would like to get this area covered. Side skirts possible?

The undercarriage of the car is pretty flat, very well paneled. I doubt anything done here would significantly reduce drag.

I saw that one guy made air separating fins for his back bumper. I can't find those to buy anywhere... would have to make them. How successful were they, I wonder...

The car is a little high but that's a safety measure in my view.

I use the trunk frequently so a kammback is out of the question.

Blocking the grill may be a possibility. I saw some pool noodles at the dollar store for $1... I wonder if those would be feasible?

[post in progress... pics coming]

Years ago, I drove taxis in the NYC metro area. Uber and Lyft is similar when it comes to tipping: the car appearance will matter for some passengers in ways that will be reflected in the tip. You want a simple car--civic is great--and you want it to be comfortable, clean, and "presentable." For the last, keep the mods stealthy and low-key. You might be delivering someone to a date or a special event and they might feel awkward if they think the car looks "weird." You might see their displeasure in tips or reviews.

No kamm back (unless your fabrication skills are really good).

Side skirts are good (but again, make sure it looks clean and OEM as possible).

Grill block for the LOWER grill on that car. Black plumbing pipe insulation might be better. Very stealthy and easily reversed.

Pump your tires to maximum sidewall to reduce RR. It will modestly affect road noise but nothing serious.

Your best bet for improvements with this car, for this purpose (Uber) will be hypermiling. So you need a better MPG gauge like you need a good navigation app. UltraGauge, ScanGauge, torque app with OBD2 dongle... take your pick. They will pay for themselves sooner, rather than later.

Love the car, BTW. Eigth Gen civics were among the best looking in my book.

Lots of good advice. I'll second the basics: air up your tires, keep your speed down on the highway, consider a partial grille block when the weather is cold, and practice driving techniques. Most other mods will either have much smaller returns, or will severely impact usability or aesthetics of the car.

I'd like to caution you, the 2nd gen Civic hybrids were notorious for very early battery failure, moreso than any other hybrid I've heard of. I want to say I read somewhere that Honda was seeing rates as high as 30% by just 4 years old.

They are also notorious for getting worse gas mileage when the hybrid battery is significantly degraded.

Yours may be on its last legs.

This car has 127k miles. Battery never been replaced. I was thinking about replacing it since I expected high 50s fuel economy... however the more I learn about this car it seems that it's economy mostly depends on where you drive. The docs I've seen on CleanMPG seem to suggest 40mpg during acceleration, and in that context the mpgs I've seen make sense because there are stops every half mile here it seems and lots of rolling hills so the car is in a constant state of acceleration and deceleration. I suspect 45 mpg is likely the best I can manage, although I do wonder about the acceleration problems... the accel is about half what it is for my Corolla 2002. What could that be about?

Regarding ODBII, I tried to read codes with an Android reader that works on the Corolla, but the vehicle wouldn't power it. Do Honda and Toyota use different ODBII standards?

I haven't sat behind the wheel of a 2nd gen Civic Hybrid, but the first gen and Insight both have insanely tall gearing, and for the CVTs, try to keep the revs down. Honda's secret sauce to great fuel economy is to use the smallest motor they could get away with, with the tallest gearing that didn't make the car undrivable.

The 1st gen and Insight have lean burn. This model doesn't due to political pressure. Also the reason the battery has problems... the battery has 30% less capacity than the Prius but is expected to push the same load. I suspect Honda had lean burn in the spec but then got hit with bad press/advocacy and panicked, cut lean burn and stuck with the battery they'd already ordered. A knee-jerk design, in other words.

In terms of revs, the car won't rev past 3200rpms at all, and it's impossible to accelerate without it hitting at least 2300. I keep the pressure steady because it does no good to floor it (revs out and accels slower), and sports mode is a no-go.

That doesn't sound right. Redline for that engine is 6300rpm, and it should continue to build power until around 6k.

Maybe the battery is dead and was bypassed.