http://www.youtube.com/watch?v=_09tPHmDR_c

Pretty cool. This sure beats GMs 2 mode setup. It gets 30mpg gasoline after its initial plug in charge is used by using a Saturn 4cyl and stronger electric motor. And it out tows a 5.3L Suburban. Another reason not to be worried about 35MPG CAFE. Maybe the year 2020 version of the 2 mode system will look something like this. I wonder what curb weight is, although maybe it really doesn't matter if you are getting 30mpg.

 

Awesome!

...But they pulled out the stock 5.3, not a 5.4 BLASPHEMY!

How does a 1.9L have the same power output as the 5.3?

If that's true, why did GM use the 6.0L for their new two mode system? They should have used something much smaller and more efficient if power output ends up being the same???

 

It's a series hybrid? Just like the volt plans to be.

How much did it cost to retrofit it? I didn't catch that...

 

Sorry but I am calling BS on a lot of the things said in the video. I seriously doubt that a 1.9 4 cylinder will allow a Suburban to pull the same way as a 5.3 when the batteries aren't 100% charged. As the charge drops down to 20% power, as the guy said, the engine runs to charge them back up. I really doubt the 1.9 has enough power output to power both the vehicle and charge the batteries while doing serious driving or towing for that matter.

 

This says it is a parallel http://en.wikipedia.org/wiki/Andrew_A._Frank This guy also has a few other vehicles.

 

I am not convinced either, but it sounds to me that he was saying the 1.9 is charging the batteries and running the vehicle, but when it needs acceleration, the batteries are powering the vehicle as well.

I would maybe see this considering that the 5.3 is using AFM. So, the Suburban is using ~ 2.65L, about 160hp (guessing that with AFM you get 1/2 hp). Using the 15% loss, that is about 136hp.

Output of the Saturn 1.9L is probably 124 hp (92 kW) and 122 ft·lbf (165 N·m). With a more efficient transmission, 95% makes it to the rear wheels, or about 118 hp.

I guess it is possible. I would like to see more evidence though, and I am not a big fan of CVT's.

 

Electric motors are much more efficient and can be much more powerfull then a 5.3 v8 engine. I think that the saturn engine in that vehicle is mainly just to keep the batterys at a certain state of charge.

 

I'm not seeing where it says what each vehicle is?

 

it could possibly work well when your in traffic or sitting for periods of time so the saturn engine has time to recharge the batteries

however on the highway at a steady speed i'd expect the saturn engine would have to be running at a high RPM to push the mass of the suburban, probably getting worse fuel economy.

i'd love to see more research and test cars like this though

 

What RPM does a AFM 5.3L run at when in 4cyl. mode? I don't think it would be any different than that. Those Saturn 1.9L engines were pretty efficient in the S series, SOHC 1.9L was rated at 40MPG hwy

 

i don't know but even in 4cyl mode its got more displacement then the saturn motor, probably delivering more torque at the same RPM.

wish we had more info

 

It prbly takes ~25hp to keep the SUV going 55mhp once it reaches that speed (more to get there faster). That saturn motor can easily produce more than that.

 

Engines typically achieve their best fuel economy when running at 75-80% power output (if we measure things in unit mass fuel per unit energy output, typically expressed as pound/horsepower/hour). The situation you describe would indeed be a good thing.

Ever notice how efficiently your lawnmower runs, even though it spends most of its life near its peak operating speed?

 

The guy isnt a crockpot, and ITS Davis has done some interesting research over there as well. When he says it has similar performance - I believe it.

But again, you're talking a plug-in with a 4 cylinder. That helps it out a lot. No matter how efficient that saturn engine is, its pushing a vehicle of over twice the mass and with much higher aerodynamic and also higher rolling losses from larger tires. The plug-in addition is what really gives it those great mpg numbers.

Personally, I'd have wished his students could have used one of the newer 4 cylinder diesel engines from europe. That would make this even more striking in terms of mpg!

Heck, even the 2.9L diesel (if mated to a plug in or dual mode hybrid) should be able to get the suburban some great mpg numbers! Thats something GM may do in a few years on their own.

While GM is concerned with CAFE, part of me still doesnt totally believe the "sky is falling" mentality. If an SUV this big can be made to get 30mpg by a bunch of [really dedicated] college kids, GM's gurus can get it done. Things may be more expensive - but again - meeting CAFE isnt the end of the world.

 

Lets make some assumptions.... Let's say this is the "next big thing" and everyone in america buys NOTHING but plug ins for one year.... that's like 10 million vehicles, in just one year (I know HUGE assumption) but has anyone stopped to think what that would do to the demand on our power grid? That "70 cents per gallon" will skyrocket. Utility companies will need to upgrade their power facilities, more power plants will be needed, which means more coal (price will $$$) also more nuclear plants (disposal of waste is very $$$) it's just a big snowball, it's a nice stop gap, but until we have the means to create clean power for everyone (hydro, wind, geothermal, etc...) it's not a truely viable alternative....