Although Honda's concept cars will grab most of the headlines after its 2011 Tokyo Auto Show press conference today, the new drivetrains we sampled yesterday at the automaker's Twin Ring Motegi are just as big a deal.
First up is a all-new family of four-cylinder gasoline engines, and yes, they are direct-injected (finally). Eventually, you'll see displacements of 1.5, 1.8 and 2.4 liters, but the 2.4-liter will show up first, almost certainly in the redesigned, U.S.-spec 2013 Honda Accord, which should show up in the spring of 2012. (Yes, just ignore the fact that the prototypes we drove were current-gen, European-spec Accords.)
Honda's estimated ratings for the new 2.4-liter engine are very conservative thus far -- "over 181 hp" and "over 177 lb-ft" of torque -- and barely more than you get with the current port-injected 2.4-liter. Engineers tell us this is just a starting point, though, and that the production engine will likely fare better. Note that these rating are for 87 octane; for a 91 octane version, Honda could swap out the pistons (thereby raising compression) and get more power.
The most interesting thing about this engine is what's going on with the i-VTEC camshaft profiles.
You still have two camshaft profiles to vary the amount of intake valve lift, but on these engines, there's no hard switchover point to the hot cams. Instead, you have the normal camshaft profile and a new efficiency-oriented Atkinson cycle camshaft profile (that keeps the intake valves open into the compression stroke).
Coming off idle, the engine is using the normal (higher-lift) profile, but unless you're on a dragstrip, it's going to switch to the Atkinson profile as soon as possible -- by 2,000 rpm. If you gradually increase speed with a steady throttle input, the engine might stick with the fuel-miser cams. "Even at max rpm, the Atkinson could in theory be active," an engineer tells us.
More likely, though, you will have floored the throttle by that point, and whenever that point is, the engine will switch back to the normal, higher-lift cams. But on these new engines, that transition could happen at any rpm. "At the end of the day, it all depends on how much torque is needed for the given driving conditions," the engineer tells us. And no surprise, the Atkinson profile results in a shallower (less potent) torque curve.
Hang On, This CVT Doesn't Suck
Other details on these new engines, like the cylinder bore diameter, stroke, etc., will have to wait, but we're told to expect a 5 percent increase in fuel efficiency. The new continuously variable transmission (CVT) we tried with the new 2.4-liter in our Euro Accord/TSX mules would be good for an additional 10-percent improvement in consumption.
We've wasted no love on mediocre CVTs, but this new one is threatening to give this ordinarily infuriating species of transmission a good name.
"Usually, with CVTs, you step on the gas, there's a bit of a lag, and then the engine starts screaming," says our engineer. "It feels very unnatural."
With the new CVT, Honda is using a new control module that better coordinates the transmission's hydraulic controls with the gear mapping and the ECU. "You get a smaller transmission kickdown than before [hence, less screaming], and at the same time, the engine is called upon more quickly to increase torque. There's a shorter lag, and there's a steeper acceleration curve."
During our very short test drive, this CVT proved a lot more likable than most CVTs we driven, and its responsiveness reminded us a bit of Mazda's new six-speed automatic transmissions -- a total apples-oranges comparison, but what are you going to do about it? Although we expect the CVT to show up in the next-gen Accord, Honda engineers told us it might not replace the five-speed automatic in some markets.
New 1.6-liter Diesel Is TBD for USA
Honda still isn't making any promises about bringing a diesel engine to the U.S., which irks us more than ever, because the new 1.6-liter turbodiesel four-cylinder we tried in another Euro Accord mule is rather impressive. It's not as amazingly rev-happy as Mazda's new Skyactiv-D 2.2-liter, but this all-aluminum engine is still pretty free-revving, smooth in its delivery and ample in the low-end grunt department.
Our tester had a six-speed manual gearbox, and was rated at a modest 118 hp at 4,000 rpm and 221 lb-ft of torque at 2,000 rpm, but the engineers say they're working on a higher-performance application that would deliver something on the order of 158 hp and 258 lb-ft. In Europe, this i-DTEC 1.6-liter will replace the current 2.2 diesel.
moparbad says:
06:09 PM, 11/29/11
Signs of a competitive pulse from Honda, perhaps Honda will shake off it's funk of mediocrity.
coolb944 says:
12:37 AM, 11/30/11
Finally! Some signs that Honda still has real engineers working in R&D and not just some robots programmed to spit out the same old same old.
blackdynamite1 says:
07:07 AM, 11/30/11
May not matter if their redesigns continue to look like ass
BD
ed124c says:
07:37 AM, 11/30/11
I was hoping the new engine's torque curve might have a nice plateau, but the graph says otherwise. Oh well, 15 or more extra ft lbs and only 181 hp is probably better than 162 ft lbs with 190 hp at 7,000 rpm.
rayzor says:
07:59 AM, 11/30/11
Lots of catching up to do, still; we'll see how things pan out in the next year for Honda
cr_driver says:
08:17 AM, 11/30/11
Keep working to catch up!
transpower says:
08:59 AM, 11/30/11
I like Atkinson engines and CVT's, but I wish that the auto makers would construct real Atkinson engines--meaning that the expansion/compression ratio is physically greater than one. Currently, the auto makers use valve timing to achieve somewhat the same effect, but it's not the real thing.
duck87 says:
09:01 AM, 11/30/11
The problem with Direct Injection is intake valve deposits; something that you will fully understand if you've ever owned a Vee-dub group product that offers this technology and your car loses a ton of power after 5-6 years. Since the information coming from Honda seems to indicate that they extensively redesigned and developed the EGR system (this probably reduces the fouled intake problem), they probably only felt that now is a "safe" time to introduce the technology for long term reliability.
I'll be honest, I still don't see many benefits with DI in naturally aspirated engines (turbo engines is another matter)... it boosts midrange torque but at the end of the day it's only "slightly enhanced fueling", and there are other factors that come into play in engine design at extremely low and high RPM.
I think this is good news, considering how old Honda's engine lineup is. In one fell swoop they've just unleashed a series of powertrains that will probably take them to the top again. Maybe. Having all this implemented in 2-3 years is hard to believe...
duck87 says:
09:49 AM, 11/30/11
@transpower: The only "real" Atkinson cycle engine I know of is used in portable power generation... coincidentally by Honda: http://world.honda.com/powerproducts-technology/exlink/
zeniff says:
11:04 AM, 11/30/11
I'd rather drive the TSX seen above with Honda symbols on it than badged as an Acura with that awful beak.
nisslover says:
12:49 PM, 11/30/11
Sooooo...... no one is upset with the fact that Honda is considering putting a CVT in the Accord?
angry_mushroom says:
02:54 PM, 11/30/11
A CVT in a Honda? We'll see how this turns out.
blueprint1 says:
09:39 AM, 12/ 1/11
I won't mind the CVT if they keep the manual option. Good to see Honda move ahead with interesting technolgies on mass-market cars. Keep up the good work!