Featured Toyota Says You’ve Been Misled—Most “Hybrids” Aren’t Really Hybrids

it's the internet, we have to argue

 

You were talking climate impact, that involves carbon emissions. A study from several years back(was discussed here) calculated the 'best bang for the buck' in terms battery capacity for reducing carbon emissions from the personal vehicle fleet. Building a bunch of diesel mild hybrids does more for that reduction than a few full hybrids and plug ins.

With the battery from a Rav4 PHV, we can replace...

• 1 ICE SUV with a PHEV
• 18 ICE SUVs with full hybrids
• 90 ICE SUVs with diesel mild hybrids

A single PHEV will reduce an individual's carbon emissions by a lot, but leaves a lot of straight ICE cars on the road. More hybrids means even greater carbon reductions over the entire fleet.

Aside, how does the commute cost less than a BEV when even the bZ4X is more efficient?

 

Where can I get my diesel mild hybrid please?

Hopefully a small sedan or hatchback with a stick-shift.

 

High compression Diesel is not built to be start/stopped. It must run constantly to be efficient. In theory a constantly running diesel w/ battery backup would work - but that's countering what we think of as a hybrid.
.

 

There was a standards based list available a while back. It specified the various types. There were:
series hybrids
parallel hybrids
series/parallel hybrids
mild hybrids

The Mild hybrids are often set up to use a hefty battery to start and stop the engine.

 

I'm not sure that's true.

I used to hypermile my 1985 VW Golf diesel with something like a 23:1 compression ratio, and it seemed to work pretty well, stopping the engine and then starting it, either with the starter or by the car's momentum.

 

Better let Toyota know then, since that's what their Hilux mild hybrid does.

All engines need to run at a constant point for best efficiency. That does preclude them from being stopped and started again. This sounds like a rationalization to continue the practice of idling diesels, which is no longer the case.

 

If I wanted to show Toyota how to do it:

• Start with a Prius Prime
• Replace all ICE with equivalent weight battery
• Hack/replace control laws transaxle controller

But why bother when used Teslas are a better base.

Bob Wilson

 

Diesel nowadays under CARB rules - modernly is a FAR cry from mid 80's 1.6 liter 4 banger (compared to modern dual battery 6½+ L) . Old little diesel engine fuel pumps pressure could easily be under 4K psi. Emissions standards now require better atomization of fuel, requiring 10Kpsi pumps.
To make them as clean or cleaner than a gasser - there's (dpf) diesel particulate filtering, selective catalytic reduction (scr) systems, (def) diesel exhaust fluid .... & like gassers, an EGR. Start stop cycles on diesels quickly load up a DPF, which sends the system into a regeneration cycle .... & if that's shut off by starting stopping (regularly), the dpf WILL load up to the point where modern diesels will go into a power limiting cycle (limp mode) that can reduce top speed to easily mean under 40 mph. Pray to God you're not on a hill pulling a trailer under those conditions.
That makes one wonder - could the Helix meet CARB compliance? I suppose possibly. Those are just some of the theoretical DIESEL/CARB issues.

https://carfast.express/en/news/auto/toyota-hilux-in-the-usa-everything-you-need-to-know-about-importing
Yea - so there you have it. So much for your modern carb diesel / stop/start ever coming to fruition in the states. & speaking of tougher standards - last couple winters (for a week or 2) we hit temps below -20°f & a couple of those days were below -30°f. Try & pour diesel #2 at those temps - much less force it through a 2 or even a 10 micron fuel filter (necessary for high pressure 10,000 PSI pumps modernly) . Fortunately we have one of those VERY rare stations maybe 10 miles away that sells #1 fuel (extra 90¢/gallon) that's closer to kerosene which doesn't solidify into wax the way #2 will (w/out pouring in enough anti-gel treatment). Fuel viscosity concerns start around 20°f & progressively worsen w/ Sub-0°f temps).
But yeah we ARE a creative species & one might suppose that if there's a will - there's a way.

 

Once warm naturally aspirated diesels restart much more easily than a gas engine firing on the first compression stroke.

make naturally aspirated diesel hybrids with the hybrid part to make up for power/acceleration and you have a much more reliable and efficient all weather offering

 

I've never heard of start-stop technologies causing diesel particulate filters to load up. What does cause a lot of particulate matter is the exhaust gas recirculation system as the vehicle runs.

We have dozens of diesels at my place of work. What I have seen is when regen mode is shut off repeatedly (regen, as in burning off all the particulate matter in the exhaust filters, for all you who thought I was talking about hybrid regen.) That will cause them to go into limp mode.

 

Not quite sure I understand the above - as it sounds like you're saying you've never heard...... but then you have heard ....
Apart from that - it sounds like we're on the same page of understanding. Our Duramax pickup takes about ½ hour of constantly running to complete its regen cycle. That seems consistent with what others experience.
DPF Regeneration - A Comprehensive Guide .

If you have start stop, yet diesel needs to have a running DPF burn off cycle, then it's somewhat of a dichotomy.
That is likely the lion's share of the reason (linked in post #49) that Toyota wouldn't justify the financial benefit/burden of making the Helix carb/USA compliant. That, & Toyo's offerings in the USA are already covered pretty much in the pickup & SUV market.
.

 

You said that diesel particulate filters clog from starting and stopping. But that isn't the issue and a diesel could start and stop most of the time, no problem.

That is during the regen cycle. Yes, the engine must run constantly for that, and turning it off before it's finished, then doing it again and again and again, can allow the particulate filter to fill up more than it should causing the vehicle to go into limp mode and then you have to take it to a dealer to have the filter cleaned out or replaced.

But how often does it need to go into regen mode? Most diesels I've seen take weeks, if not months, to get enough particulate matter in the filter to trigger the regen mode. All those times there shouldn't be an issue with start-stopping a diesel.

A lot of what made diesels better than gas have been affected by modern emissions. It's not just having to run for half an hour, it's also injecting diesel fuel into the exhaust in order to create enough heat to burn off the particulates.

But which is better?

• A diesel that stop-starts even though it has to regen and inject fuel into the exhaust for half an hour every few weeks or months?
• A diesel that runs constantly, even when no power is needed, but still has to regen?
• Or forget diesel, just get a gasser and call it a day?

That's usually the case. Just different points of view, but the same root understanding.