Actually, I believe the ECO light means you are getting an instantaneous FE of 29 MPG or greater. Now, that usually happens when 3-cylinders are in use instead of six, but it can happen with all six cylinders firing.
I am quoting this out of my memory of the articles which came out when the HAH was first released, so I may not have the number exactly right. But it is an indication of instant FE more than an absolute indication of when only three cylinders are being used.
I read an article on here that said it means you're getting 25 mpg or better. But, watching my FCD, that's not true. At least, not according to the display. I've had it around 40 mpg with no Eco light.
I'd like to read the sources that say its a function of FE- were they anything definitive from Honda? Could you find one and post? There was lots of unintentional misinformation spread when the HAH (or any car for that matter) was released- journalists confusing facts or simply not soing their homework.
The Odyssey has the same system & same light on the dash.
If you are on a smooth road you can feel/sense the cylinders come on or go offline, and it is always synched with the eco light's appearance/disappearance. It's more noticeable on the Ody- larger engine.
In my car, I can feel something kicking in and out separate from the ECO light, with the ECO light still on. It feels pretty much like a transmission shift, but isn't, because the tachometer is unaffected. At cruising speed, anytime I push on the accelerator, even seemingly 1/16", I get this "shift." ECO remains lit. (If I push on the gas a little more, ECO goes out, and there's no percepible mechanical change at this point.) I strongly suspect it's the 3 cyl. mode kicking in, and it's not associated with the ECO light. More evidence is that at some speeds, like about 52 mph, there's a noticeable amount of what seems like engine vibration that appears when letting off the accelerator a little and prompting this "shift." The car is supposed to have engine mounts that help eliminate vibration, but in my car at least, I can easily feel it.
My "lifetime" mpg over 6500 miles is over 35 mpg, so I don't think my ECO/3-cyl system is defective. (Maybe the engine mounts have a problem, and/or my car is "rough" when engaging 3-cyl mode, as others report they can't feel it.)
I'd like to read the sources that say its a function of FE- were they anything definitive from Honda? Could you find one and post?
FOUND IT!! Sheesh! It took nearly an hour to scour the net to find where I saw the thing about 25 mpg and eco...
The suspect text is below, in red:
Accord hybrid the best one yet
CARLSBAD, Calif. — Each new gas-electric hybrid model leapfrogs previous ones in refinement, power, familiarity. Predictably, then, Honda's 2005 Accord hybrid is the best so far, by far.
The 2005 Honda Accord hybrid.
The Accord hybrid, not on sale until December though gas-power '05 Accords are already at dealers, can claim several firsts or bests.
It has the biggest gas engine — a 3-liter V-6 — yet mated to an electric motor to create a hybrid. It's the first hybrid more powerful than the gas-engine equivalent: 255 horsepower vs. the gas V-6's 240 hp. It's the first hybrid that shuts down half the engine's cylinders under light load to save even more gas.
And it's the first that drives so conventionally that you honestly wouldn't know if somebody didn't tell you, or you didn't spot the small "hybrid" badges.
Interior of the Honda Accord Hybrid.
One reason the Accord hybrid has such an easy familiarity is that it uses a conventional automatic transmission instead of the continuously variable transmission (CVT) that Toyota and Ford favor for hybrids. The normal feel of the Honda gearbox is a welcome respite from the rev-happy CVTs.
The Accord hybrid's only significant drawback is price, about $3,400 more than the similar gasoline model, which is more or less typical of hybrid pricing. Honda says the Accord hybrid will be about $30,000, offered only as a high-end EX model, luxed up with leather and such.
Honda's hybrid system — IMA, for integrated motor assist — always uses the gas engine, then kicks in the electric motor for more power when needed. Toyota and Ford do the opposite, relying on the electric motor as long as possible, then starting the gas engine when needed.
Honda's IMA hybrids typically get better fuel economy on the highway, as conventional gas engines do. Toyota and Ford systems are better in town.
Neither type needs to be plugged in. The batteries are recharged during braking and, if necessary, via the gas engine. Both systems shut off the gas engine at stoplights and other long pauses to save more fuel.
Slightly twitchy steering is a flaw that a sensitive driver might notice. It won't stay centered as you'd like and seems overboosted just off-center. Thus, the hybrid starts drifting one way, you turn the wheel the other, the car over-responds and you have to turn the wheel back. "I agree it feels a little weak on-center," says chief engineer Tetsurou Hamada.
Partly that's due to electric power steering, which feels different than normal power steering. Electric power steering, however, uses no engine power, so no fuel. A normal hydraulic power-steering pump is driven by the engine, creating drag and consuming fuel.
Accord hybrid also has wider tires than the gas-power model. Wider tires have more traction, which can emphasize steering-wheel movements. The hybrid is 117 pounds heavier than the gas model, and Honda thinks that dictates wider tires to avoid handling and braking compromises.
Other minor gripes:
• The gearshift lever moves too easily into "D3" instead of the regular drive gear. D3 enhances performance but uses more fuel.
• Expected features are lacking. For the price, the car ought to have auto on/off headlights. All four power windows, not just the driver's, should go up or down with a single touch. The inside rearview mirror ought to dim automatically when hit by headlights.
Does the Accord with IMA work? Surely, and well.
The system never is intrusive. Its extra power is especially noteworthy in full-throttle scoots from 30 to 50 mph, useful in suburban driving. Honda says the hybrid accelerates from standstill to 60 mph in 7.5 seconds, half a second more quickly than the V-6 gas model.
The shift between six cylinders and three is usually undetectable. A dashboard light illuminates when the engine's getting more than 25 mpg, and that's usually when it's on three cylinders.
Accord hybrid is rated 30 mpg in town, 37 on the highway. The V-6 gas Accord is 21/30. A four-cylinder gas-power Civic is rated 31/38.
The trip computer in the hybrid test car, driven with no thought of maximizing fuel economy, showed a best of 33 mpg. That was a 25-mile stretch on back roads near here. Slow, winding two-lane roads registered 31.9 mpg. Hilly interstate, with the cruise control at 70 mph, registered 26 mpg.
A V-6 gas Accord, tested under typical but different circumstances, preventing apples-apples comparison, registered 18.2 mpg in suburban driving, 30 mpg during a short highway run at 65 mph.
The best you can say from all that is that the hybrid uses less fuel, but — typical of hybrids — not enough less to financially justify the purchase. In fact, it would take you more than a decade to save enough on fuel to repay that $3,400 price premium vs. a gas Accord, assuming today's gas prices, 12,000 miles a year and fuel economy as good as the ratings.
Honda agrees it's a no-win viewed strictly that way, which is why the Accord hybrid also will be sold as the highest-power, top-of-the-line Accord, and marketed as the one to drive if you really care.
The only factory option available on the Accord hybrid is a $2,000 navigation system, same as on the gas-power cars. It's wretched.
But that's a detour. The main route is the hybrid powertrain. It's as close to terrific as anybody's yet come, and it's embedded in a well-executed, nice-driving sedan that's already very popular. Honda seems silly planning just 20,000 Accord hybrids a year.
2005 Honda Accord hybrid
•What is it? Gas-electric hybrid version of the midsize Accord four-door, front-wheel-drive sedan. The hybrid is manufactured at Sayama, Japan, instead of in Ohio, where most Accords are built.
•How soon? On sale Dec. 3.
•How much? About $30,000, about $3,400 more than a gasoline model; about $32,000 with navigation system.
•How thirsty? Rated 30 miles per gallon in town, 37 on the highway, vs. 21/30 for V-6 gasoline Accord. Test car's trip computer showed mid-20s to mid-30s in a variety of driving.
•Who'll buy? Slightly younger, richer, better-educated than typical Accord V-6 buyers; hybrid target is college-educated married man, 50, with $100,000-plus annual household income.
•What's the drivetrain? 3-liter V-6 with variable cylinder management that shuts off three cylinders in light duty; mated to an electric motor, five-speed automatic transmission and traction control. Honda rates the hybrid system 255 horsepower at 6,000 rpm, 232 pounds-feet at 5,000 rpm (vs. 240 hp, 212 lbs.-ft. for 3-liter gas V-6).
•What's the safety gear? The expected bags and belts, plus anti-lock brakes; front-seat, side-impact air bags; side-curtain air bags.
•What's the rest? Available as an EX model, the hybrid comes with leather upholstery; heated front seats; power steering, brakes, windows, locks, mirrors, driver's seat; dual-zone climate control; AM/FM/six-CD stereo with XM Satellite Radio receiver; cruise control; remote-control locks; tilting, telescoping steering column; P215/60R-16 tires on alloy wheels; flat-tire repair kit; no spare tire.
•How big? Identical outside to a conventional Accord but 5% more interior space because there's no headroom-slicing sunroof, and 3% less trunk space because the batteries are back there. Accord hybrid is 189.5 inches long, 71.5 inches wide, 57.1 inches tall on a 107.9-inch wheelbase.
Weight is listed as 3,501 pounds.
Passenger space is listed as 102.7 cubic feet; trunk is 11.2 cubic feet.
•Overall: Nicest execution of a hybrid yet, but, as with other hybrids, high price is an issue.
"The Accord Hybrid's instrument panel incorporates an exclusive meter display that shows key operating indicators of the IMA system, including the state of the IMA battery charge, the level of IMA motor assist or charge, and a light to indicate Idle Stop mode. There is also an "ECO" light to indicate that the vehicle is achieving a high level of fuel economy and the VCM is operating in 3-cylinder mode. "
Just one other comment, on what appears to be a misunderstanding of the difference between Average FE and Instantaneous FE. The HAH only displays Average FE. It doesn't give you any reading of what your fuel efficiency is right now - at least not without Navi. I can't speak for what additional features Navi may have. So, instead, Honda has given us the ECO light to represent Instantaneous FE.
The HCH and Insight have displays of both Average and Instant. FE; I guess us Accord owners just aren't interested in what mileage we're getting at any particular time...
Thanks for the info. Bar, I recall reading that too- I think that one is not correct. Any V6 engine can get well over 25 instantaneous even normally- dunno why Honda would set the 'eco' bar so low.
Then notice that the Honda statement Drourke dug up (thanks) is an "and" condition. Both need to be met for eco to come on. Press releases are worded very specifically for legal reasons; its unlikely they conveyed inaccurate information.
Dale- You may be feeling the torque converter locking up (around 48) and VTEC changing timing, generating extra power that you feel as an impluse? And there is a little latency between the light and the 3cyl nudge I feel, especially when I'm on-off-on-off.
Of course, you could all also be correct and I am simply wrong. What we need here is a real Honda guy to weigh in. At any rate, I feel its still pretty safe to say that for most intents and purposes, "eco" = 3 cylinders, especially when explaining to others. There, I caveated myself.
On second thought, after writing my ethanol post and commenting on the unwillingness of eco to come on, maybe there is a minimum MPG 'interlock' that has to be met...