Diesel hybrid, better or worse mpg?

I think the new Hilux has a mild hybrid diesel option.

The big issue for full hybrid diesels is cost. There is the more powerful motors, larger battery, diesel engine, and the emission controls. Ford had a couple of concepts around when the gen2 Prius came out. They said that would all add $9000 to price. It can work out in places like Europe, because fuel prices and efficiency make diesel more popular to start, and their emissions are less stringent than the US.

A diesel might work better as a range extender. It can run at high loads all the time, which is where it produces the least amount of NOx. Emissions controls would be cheaper than for a diesel running with variable loads.

 

I follow this guy on Tik-Tok who's building electric logging trucks: http://www.tiktok.com/@_edison.motors

He's putting enormous diesel generators in them and according to the regulators you can use the cheaper dyed diesel fuel because the engine isn't powering the wheels, it's powering the electric motors: Edison Motors

If you want to talk about a diesel hybrid, this is the one that's most interesting to me.

His main motivation is he's been waiting for a Tesla semi-truck for 1/2 dozen years and got so tired of waiting he decided to build his own:

 

If it can use off road diesel, it probably doesn't meet on road emissions.

 

The point of that particular video was that it's not considered on road emisisons because it generates electricity rather than generates rotational force directly to the driveshaft and in Canada Electric vehicles don't have to pay road tax: Using dyed diesel to save money - TikTok

 

It's a bit different with heavy equipment in strip mines and logging because generally you're going downhill when loaded and uphill when unloaded. That's not always the case, but when it is regenerative capacity is significant, especially in mines where you can actually design the hills in a way that optimizes your regenerative capacity.

There's too many factors to say any of this is completely true, but if you can design your vehicle and road system to take advantage of downhill regen you can do some really interesting things with super heavy weight diesel hybrid or all electric vehicles.

Also as an aside, this article recently came out: The Cybertruck is more expensive to supercharge than a Ford F-150 costs in gas | Tesla Motors Club

 

Hey fellas, what's going on in this thread??


Diesel-electric drive has been a thing for railroad locomotives for a very, very long time.

 

Excellent point leadfoot... Locomotives have been ahead of the rest when it comes to diesel-electric

Hybrid locomotives will effectively replace traditional diesel locomotives in the future - Railway Technology

 

And the emissions for off road equipment like generators is nearly always more lax than for cars and even commercial trucks.

These are PHEVs. Edison Motors also has BEV versions of the trucks. Being disconnected from the drive train lets them run the diesel at its most efficient point for extended intervals by charging the big battery. Which offsets the conversion losses series hybrids see, that get worse at higher speeds.

Nissan makes series hybrid(no plug) cars. With the hybrid szed battery, the engine ends up running at veriable loads like most other cars. They haven't brought them to the US because the EPA highway economy wouldn't be impressive. The i3 REx mpg is worse than some ICE compact cars.

They switched to series hybrids to reduce costs, and a mechanical transmission for a freight train was impossible. The steam contemporaries were still more powerful. Don't know if the diesel-electrics used less fuel, but did need a lot less people to run, and cost less in maintenance.

The short comings of mechanical transmissions are why really heavy equipment are diesel electrics. Ships use it for better center of gravity, and turnable prop nacelles are more maneuverable.

Efficiency isn't the only reason to go hybrid.

 

I've argued before that the raw simplicity of the Prius power split device contributes more to the fuel efficiency of the Prius than any of the stuff that happens electrically.

It's a way to couple a gasoline engine directly to the wheels with extremely low loss and enough variability between input and output RPM to allow the gas engine to stay in a nice efficient operating regime.

The fact that the compensations to allow this are occurring electrically are a matter of convenience- it is easier to do it that way than other ways, but the real raw efficiency earned is by directly coupling the engine to the wheels using very few parts and bearings.

 

But does that loophole apply in the U.S.?

 

Plenty of hybrid transit buses are diesel-electric hybrids. In my region, King County Metro runs the largest fleet of hybrid buses in the country, and they are diesel-electrics.

Hybrid electric bus - Wikipedia

King County Metro fleet - Wikipedia

 

I have a plug-in hybrid, a BMW i3-REx, and it has a two cylinder, modified motorcycle engine. I would have no problem if it were a diesel or Atkinson modified. But this is not high on my list of priorities because 99% of its miles are electric. It actually has to periodically run an automatic cycle to keep it operational . . . much like my emergency home generator that runs ever Saturday morning.

Bob Wilson

 

Amy BMW modders done upgrade work on i3 generator? If you can share some links I'd love to learn about what's possible.

 

Hybrids are generally constructed to allow two or more flawed devices to compensate for each other. In the original Prius design, the objective was to use the ultra low pollution Atkinson cycle gas powered engine despite the very low torque that made it difficult to accelerate from a start. Getting great mileage was not a goal originally. The electric motor provided the needed torque without extra emissions and the gas engine provided necessary HP to run the generator to top off the hybrid battery. A secondary weakness of the ICE power-train was the extreme emission levels that were common when the catalytic converter was cold. The Toyota design got around that problem by alternating back and forth between ICE and EV modes in such a way that the CAT never got cold and the battery was never over charged or discharged to the extreme.

So the question is "What flaw in the Diesel power train are you trying to fix?" There are several flaws ranging from soot emissions to the smell of un-burned hydrocarbons. There's the sound of rattling pistons as the detonation takes place within the engine. Is slow acceleration still a problem "off the line"?

Last but not least is keeping in mind that the Toyota designs were restricted somewhat by the consent decree issued as part of a law suit filed against Toyota by Chevron. Toyota was (essentially) restricted as to the size of the rechargeable batteries that they could use in a car. It was approximately only allowed to have batteries as big as the Prius was using at the time of the lawsuit, and we know that those were pretty small battery packs. That restriction appears to have been dropped.

 

Gotcha Beat!
Diesels were MADE to be a part of a hybrid vehicle from the very start.

Fun Fact:
They were also made to run on renewables like vegetable oil, potentially disrupting the nascent big petrol empire, just reaching it's stride - but THAT is another story!



One version of....'the other story.'



The word "diesel" should be capitalized when referring to the engine, BTW...