Edmunds drives the 2011 Hyundai Sonata Hybrid; Has some interesting features

I find the opposite. The higher torque means that I don't need to downshift to accelerate or climb hills. Just punch it and it goes. I prefer cruising up hills on the highway at a steady rpm instead of hearing the engine rev up and down like in automatics or HSD powered vehicles. Like an eCVT, a manual transmission diesel is an acquired taste. I like it, but others don't.

 

If the elevation changes, so will power demand. If power demand change, engine RPM should change as well. If it doesn't something is wrong because horsepower is a function of RPM.

It is not easy for step gear boxes to change Engine RPM so it suffocates the engine to adjust power. One way is superior than the other. You decide.

 

Horsepower is a function of how much air/fuel the engine can ingest - RPM does not tell the whole picture, and neither does throttle body opening.

 

Exactly. At 1700 rpm (common highway speed), my engine can make anywhere between 0 and 80 hp. Engine speed does not need to change for power to change. I don't like suffocating engines. Good thing I drive a diesel No throttle plate to cause suffocation.

 

It ought to be. If the engine is spinning more than necessary, you are wasting fuel. One, you have more friction and two, you are at partial power and pumping loss along with it. Since you have Diesel, #2 is minimal but you still have #1.

The more power you request, the faster engine ought to spin. It doesn't have anything to do with the speed of the car but everything to do with your foot. Engine in CVT works this way. It responds to you and not you control the engine through the mercy of a preset gear ratios.

In your example, at 1,700 RPM and the engine is making 40 HP, it ought to be spinning at 650 RPM (@ max torque). We cannot assume the way our grandfather's engine works is the right way. The way ICE respond in HSD is the most intuitive and it is the right way.

Drees statement is not false. It is just a workaround to a problem for so long that we thought that's the right way. Such workaround is no longer needed because we now have eCVT.

 

No, it shouldn't be operating at 650 rpm, that is way below the optimum BSFC islands on the TDI PD BSFC map. Maybe a couple of hundred rpm below 1700, but 650 rpm is nonsense. You can find TDI BSFC maps online if you care to check.

 

Ok, I trust you on the BSFC. If that's the case then the combustion engine would be best resting and use battery power instead. Prius shuts down ICE below 15 hp and use the battery because BSFC sucks below that point.

Since electric propulsion is not available in non-hybrids, workaround such as suffocation and dehydration of the combustion is needed to make less power. I am using these words to make a point that they are the wrong ways.

 

See, that's the thing I like about a manual transmission. I am at the mercy of preset gear ratios but I have more control to make the engine do what I want it to do. I found much of that was lost with the eCVT and personally did not like it as much. If I want to climb a hill or accelerate to pass someone, I can do it without having the engine rev up and down and make a bunch of noise. I guess the point I was originally trying to make was I find a diesel with a stepped transmission to be better than a gasoline because of its torque and flatter powerband, while you find it annoying for more or less the same reasons.

 

Good question. Some things to think about.

With modern turbocharged truck diesels with electronically controlled fuel injection, the power band isn't nearly as a narrow as it used to be.

The bulk and cost of an eCVT scaled up to handle 500+hp diesel highway trucks might be cost prohibitive. The expected million+ mile transmission life might be hard to obtain. I think they might be someplace out there in the future though.

 

You have more control to the engine because the car allows you to do things that wastes fuel. Having a step gearbox (middle man) between the engine and the wheels complicate things. It is necessary as a workaround because a single engine is not suitable for all condition/speed. If you see that additional complication as ways of control then yes, enjoy them by all means.

You were in the wrong gear to begin with. If you can you pass someone in the same gear, you shouldn't be cruising in that gear. Your engine was revving higher than needed and since the sound did not get worse, you thought that was a good thing?

If you categorize unfamiliar sound as noise then yes, Prius will make a bunch of "noise". The way Prius engine sound is right because Prius is always in the right gear. It responds to your foot, not the (correct or incorrect) gear you are in.

It is impossible to for you to pass someone without revving up your Diesel engine because you have a step gear transmission. As you increase speed, engine RPM will go up. If you shift gear, engine RPM will go up or down. There is no way around it.

eCVT just need to rev up once to increase the power output and stay there. After passing, it revs back down to cruising power. Very simple indeed. The pressure of your foot equate to the thrust at the wheels. There is no need for torque multiplication by the step gearbox as it is done at the drivetrain (hybrid powertrain) level.

Everything being the same, simplicity wins - for me at least.

 

usb, your starting to crack me up.

watch the prius episode of south park before you start issuing tickets for driving an outdated step transmission.

 

I don't know what a LGV is and when I googled I couldn't find it.

CVTs have not been developed to handle the torque. Hybridization is a good route as drivers currently need to select the right gear for engine braking, a regen braking system could make it both easier and fuel efficient. Semis have lots of gears so gear ratio is not as much of a problem, software could improve and electronics can make the shifts better.

 

[ame=http://en.wikipedia.org/wiki/Large_goods_vehicle]Large goods vehicle - Wikipedia, the free encyclopedia[/ame]

 

Thannnnnks!

Really, I am not being smug. I was defending HSD for judgmental comment being made. eCVT is being ticketed for not feeling "normal". I am saying eCVT ought to be the norm and step gearboxes aren't. If that's being smug then, what can I say?

These statements probably won't pass smug test:

"The Sonata Hybrid does indeed deliver its power in a more natural manner than many hybrids."

"A CVT feels like something is slipping"

"If I want to climb a hill or accelerate to pass someone, I can do it without having the engine rev up and down and make a bunch of noise."

 

How do you define "wrong gear"? If operating very close to optimum BSFC point then I would not consider it wrong. Possibly not optimal, but definitely not wrong. Yes, I think that the sound not getting worse is a good thing. At 1700 rpm I cannot hear the engine. If I speed up to pass, it may go up to 1850, where I still cannot hear it. I prefer that to an automatic (especially gasoline automatic), which may change gear ratios to go up to 2500-3000 where I can hear and feel the engine. I imagine you like not hearing or feeling an engine running when you're at a stop. I have the same basic like as you, but just focused more towards highway driving (which I spend most of my driving time doing) than sitting and not moving. If necessary, I can always shut my car off when at a stop

Pressure of my right foot equates to thrust at the wheels in any vehicle I have driven, not just those equipped with an eCVT.

 

He is defining "wrong gear" as not optimal.

If you are cruising in 5th gear at 65mph with the engine spinning at 2500 rpm and then are able to quickly accelerate to 75mph to pass a vehicle without changing gears, it's very likely that your 5th gear is geared far too low for efficiency.

Because of the lack of a throttle body on diesels, it's less of an issue on diesels, but as usbseawolf was saying, the higher the RPMs are, the more friction there is - in general, you want the lowest RPM possible for the given engine load.

 

Have you been closing your eyes when you type things like "wrong gear"?

I'm arrogant and opinionated. Get it right!

Really you seem less in love with the exhaust smell of the prius than some on this board, but do you think no one has the right to prefer their turbo diesel or knows how to find the right gear without a Toyota computer in the way.

Think of it as favorite color. I said mine is black. Anouther said their's is red. You have chosen pink. Instead of seeing them as just opinions you decide to argue, that I'm wrong because hey black isn't really a color. Red isn't nearly as good as pink, its too dark. Its also primary which is wastefull and ignorant. People that like red really need to understand pink is better. Red is way to extreme. Those preferring black just have no clue. They don't even know black isn't a color. I refuse to add smileys because if you can't tell, I really hate pink. I want to kill all those other colors. But I can understand red because its the color of blood and roses.

 

Thanks. A cvt may help some of those vehicles, they are not far off from current design. Regen braking power and torque need to be considered in the design.

 

eCVT gives instantaneous and pretty consistent trust at the wheels. No hunting for the right gear or wasting time shifting to it. There is no middle man involved. That's the point I was making.

I feel more connected to the road with eCVT due to the lack of this middle man. For the manual transmission vehicles, the middle man is the driver (he shifts) so the driver will feel connected to the road as much as eCVT. However, the delay (in driver's head) to hunt and shift to the right gear still exists. The driver is busy shifting and may not realized it. He can make mistake too but eCVT can't. That's the difference.