Escape and Accord

why doesn't Toyota use it on the Prius, my first guess would be the added complexity needed wouldn't justify the meager fuel economy increase. Would it be easy to do it effectively, probably, I mean tell the computer to stop fuel flow to two injectors if certain parameters are met. Then tell the OBD11 system to ignore the code for misfiring on a couple of cylinders, then keep the cat's lit and up to operating temp while the ICE is pumping cold air into the exhaust system? probably not insurmountable, If you want to try it just put switches in the injectors to number 2 and 4 cylinders and once your up to speed IE: over about 38 miles an hour just shut off the 2 cylinders, then ignore the MIL and see how smooth it is, but be prepared to shut it off before the ICE goes into stealth. A couple of cold starts should put the MIL off for good. I'm not much interested in doing it, after working on equipment all day I'm no longer interested in making some thing that works good, not. But if someone else would like to try it let us know the outcome.

 

jonnycat... we have not missed your point. i understand what you are trying to say and it simply doesnt apply.

the Prius does not have an engine that puts out 2-3 times more power than is necessary to propel the car down the road.

the ICE in the Prius specifically tuned for freeway driving and for charging the battery.

the ICE in a regular car isnt. it must move the car from a dead stop. this action requires 3 to 5 times the amount of power necessary to maintain 65 mph on a level freeway. sure an automatic transmission helps a little but with the american obsession for speed, the gears are not set up for efficiency.

so you see, shutting down part of the engine is simply the realization that the car had way too much motor to begin with.

the Prius takes the same concept but goes about it in a completely different way with an engine that imho would not support shutting down cylinders very well at all. it has a CVT, engine control units and HSD that takes care of making sure all the power the Prius is producing is used in the most efficient way possible.

 

because Toyota did the different way.

Honda's approach is the variable number of cylinders.
Toyota's approach is the variable engine capacity using the Atkinson Cycle.

Regards,
Ken@Japan

 

DaveinOly,

Thanks for your post on Nov 9th above. I've often tried to convey to people how the prius engine is designed to NOT have excess capacity. It only has the capacity that it needs. (And THAT is probably why it takes a hit when it gets cold. It would take EXCESS capacity for the engine to ignore that change of circumstance. Same with the AC.)

Your description of the how and why above is better then I've ever been able to elucidate.

I hope you don't mind if I take your words a bit the next time I try to expain this wondrous car.

 

Thanks for the compliments and elucidate away.

 

<div class='quotetop'>QUOTE(tochatihu\";p=\"50357)</div>

Interesting that they STILL can't get the tax deduction right. From the Escape review:

How unfortunate, the Accord rear seats lose the ability to fold. I would have hoped Honda figured that one out after the Civic Hybrid. I hope Toyota isn't so stupid with the Camry Hybrid when it comes out. Glad I didn't wait to see the Accord before getting the Prius. But, the full hybrid design makes much more sense to me than the mild.

And Honda went with big engine, cylinder cutout to save gas, I don't think that is the right direction, even for a mild hybrid. At least the 3 cyl cutout is below 3500 RPM, the car will be running on 3 more often than I had expected it would. I suppose I would have to see the MPG specs of a (non-existant) 4 cyl hybrid Accord to compare. If they are the same as a V6 with cutout, maybe it isn't so bad a mild design after all, assuming the drivers don't punch it over 3500 RPM routinely.

 

I wouldn't be quick to ding them on the tax deduction info. That article may have already been put to press when the updated tax info was released. Subscribers get the rags a month early. Factor in a few more weeks for C&D to edit the articles, lay them out, set up the printers, print the pages, bind the magazine, and then get them out for delivery. It would put the time frame that the article was being created to right before the adjustments to the tax code were announced.

I sent them a letter remarking of the change in code. I wrote it in a manner, more of an FYI in the hopes that they'll print it for the December or January issues.

 

<div class='quotetop'>QUOTE(bruceha_2000\";p=\"50540)</div>

A 4cyl Hybrid accord would just slay in the marketplace. There's no question it would be insanely popular. I wonder if the reason there isn't one is due to lack of batteries?

 

<div class='quotetop'>QUOTE(Jonnycat26\";p=\"50590)</div>

I'm not sure. Honda chose to use the "American's love power" V6 but gave it the ability to drop 3 cylinders (they put the same engine in the 2005 Odyssey). The 4cyl AT has an EPA rating of 24/34 mpg, 6 cyl Hybrid is 30/37. It is already getting the mileage of an AT Civic. So they can claim V6 power with 4 cyl compact mileage. The power hungry American consumer will be happy.

The Hybrid Civic has a smaller gas engine than the stock car and achieves a 65% city and 24% highway improvement. IF they used the stock Accord 4 cyl, what would the MPG improvement be? It would need 25%/9% to match the VCM V6 Hybrid. Even if they got double that, would the buying public want to spend the extra $$ for 36/40 and a little better 4 cyl power?

I'm sure many would, but the delta between the 4 and 6 Accord hybrids wouldn't be all that huge like it is for the Civic vs Civic Hybrid. Unless, of course, they went back to the "same power, way better mileage" concept of using a smaller than stock 4 cyl ICE.

 

<div class='quotetop'>QUOTE(bruceha_2000\";p=\"50603)</div>

If they mated IMA with the I4 they have, and could get 40-42mpg on the highway, and sell it as a 4 cylinder with the power of a 6, they'd probably do very well. This was the tact that the car companies took in the 70s with turbos after all.

And the Accord is just, IMO, a nice car. It handles nice, it feels nice... it's no VW/Audi type car, but it's closer than you might think.

 

there is an accord hybrid forum

http://www.accord-hybrid.net

 

there is an accord hybrid forum

accord']http://www.accord-hybrid.netaccord hybrid forums

 

What struck me about the Accord article is that at $30,000 there's no mention of VSC. I never want to be without VSC again, now that I've had it for nearly a year.

C&D doesn't seem to have any problem with the vibration or noise issues mentioned elsewhere. But I still have my doubts whether the power-hungry crowd will want to pay a $3,000 premium for hybrid.