spwolf

not really, they dont like charge cycles nearly as much, thats a bit question mark right now, and reason why is everyone slowly adopting them ;-)

spwolf

btw, ideal for big cars would be V6 diesel and full hybrid system... it actually is perfect match except for:
- NVH - cold startup, start/stop during driving.
- Cost of diesel engine is a lot more than petrol... combine that with Hybrid.
- Complexity of design (a LOT more complex than petrol, less reliable).
- Ecology - diesels are still not green.

For LS for instance, you would get best possible MPG and good power by using V6 diesel and full hybrid setup from GS450h for instance. problem is that it would cost 5k extra compared to GS450h, be less powerful than GS450h, less reliable and would not have same luxury NVH as GS450h.

But as price of hybrid setups go down, we will probably see that as well.

I am not so sure about small cars and diesels, it is already expensive to have small car diesel, add the cost of hybrid setup and cost of powertrain quickly becomes 50% of the price of the car... Something that Volt is fighting against as well.

When we think about that, diesel hybrid vs petrol hybrid becomes more question of diesel hybrid vs PHEV 20/40 mile hybrid, because cost of putting an diesel in Prius is probably going to be similar to the cost of making PHEV13 Prius (13 miles plugin range of Prius). And I personally would take PHEV13 a lot sooner than diesel, simply because thats my driving pattern.

The G Man

You are correct spwolf, I had that backwards. Its the NiMH battaries that perfer the full charge cycle, I wonder why Toyota charge them at 60%.

Nextourer

Yeah.. good point lol. They say it's to lengthen the lifespan of the battery.


So Li-Ion doesn't like full charge cycles?

seanlee

i suppose i am one of the few that think diesel and electric motor doesn't really add up nicely.

Diesel is known for deliver higher power at low rpm (compared to gasoline), electric motor is also known for great torque at low rpm. So what’s the benefit when you add them together? A lot more power at low rpm, but nothing at high rpm…..
Bottom line, you want a flat torque curve that covers a wide range of engine rpm. A gas engine + electric motor is a much better combination than diesel engine + electric motor.

LexFather

Thats a pretty good point.

spwolf

not really, manufacturers have to add twin turbos to make diesels behave under 1800 rpm... or small turbos that run out of power at 3000-3500 rpms, and raises complexity and reduces reliability.

Diesels are in fact best for cruising, much better than petrol engines. And whats the worst part for hybrids currently? Cruising ;-).

On the other hand electric engines make best torque from 0 to 1500 rpm, perfectly accomodating the turbo diesel lack of low end torque. Additionally big problem with diesels is turbo lag, compared to V6 engines for instance, diesels are very slow to react. In recent Autobild comparo, they commented how RX450h's is flying by the time V6 diesel in Q7 responds. Solution for that? Electric motor that responds instantly ;-).

Problem with all of it above? 1.4 D4D 90hp engine from Auris would make Prius 3k more expensive, at least. Would be a lot less ecological, have higher maintainance costs, lower reliability, better mpg, less luxury, heavier, faster.

The G Man

Thats what the turbo charger is for

From what I understand, to get max life out of a Li-ion batteries, it should be charge at about 40%.

SLegacy99

Mmm hmm. I'd like to develop a wind turbine charging system. Make use of that potential energy during highway speeds.

LexFather

Looking at the poll here and the LS poll, it really shows how unbiased this place is. Neither is a landslide for a Lexus centered product.

CarChat really is something special

bagwell

hummm....my commute is not on freeways, but hardly any stops, road speed limits are 45mph...I set cruise on 52mph =

spwolf

i did not say bad, i said worst :-0.

I love the prius, and hybrids. As I live in Europe, i get the chance to drive many diesels from small 4cly 60hp to V8 300hp diesels.

What I said IMHO stands. If they used 1.4 D4D engine in Prius, your @75 mph mileage would increase significantly, and overall mileage would drop. But those negative points overshadow that.

I dont doubt that as cost of tech goes down, we might see diesel hybrids. Especially for SUVs and large cars. For Prius, in 2-3 years prive of their plugin prius will be very similar to the price of diesel prius (maybe diesel would be half between).

SLegacy99

Not being a Lexus owner (or Toyota) I don't feel the need to show my allegiance here. Nevertheless, when it comes down to diesel vs. hybrid, there haven't been any diesels yet that have shown that they are a better option. The closest I believe would be the 335d, however the expense negates its value.


45 MPH is certainly a sweet spot in the 400h. I've seen over 35 MPG doing roads with those speeds. I'd like to try an RX450h and see what it does.

G Star

iTrader: (2)

I really wish Audi would bring more TDI vehicles to the States. I wish we had more diesel choices with other brands as well.

Nextourer

Sorry, so you mean keep it at a steady 40% SOC or do not let Li-Ion fall below 40% SOC if you want to maintain its lifespan.