Who Might Buy Diesels?

German chamber of commerce promoting VW Diesel.
LOL

Diesel is not the future

 

That wasn't reporting bias, that was a change in the EPA formula in 2008 for all cars. After 2008, the rating for the 2004 was retroactively revised to 46 combined (48 city/45 highway).

 

Go to fuelly.com and look at the reported actual MPG for these cars and factor in the added cost of diesel fuel (or premium fuel) in the US. Get real Miles per Dollar (or distance per unit of currency).

Compare the trunk space and think of what you want to stuff in the car besides people. Do you need a wagon? IS the hybrid sedan trunk big enough? Can you fold down the rear seat? Do you need to carry anything that requires that sort of length? Use both the rear seat slid forward and the rear seat slid back as well as the rear seat folded down. Sometimes the differences are significant ... c-max smaller than v by 30 to 60%, for example, depending which seat position you use.

How long will you keep the car? What is its repair cost reputation over that term?

Once you have these, you can figure out what you need to get the cost, power, space and efficiency you need/want ... because there is no perfect car or wagon.

 

There is definitely reporting bias in internet polls like fueleconomy.gov and fuelly. I think you need to take that into account when you look at the numbers, as I reported. Don't take the numbers as truth for the fleet. The prius was 7.6 mpg bellow the old epa, the civic cvt was 2.8 above the old epa. You should not discount this, when you find that people that bought these prii to get fuel economy, did not get gains that met there expectations. I thought the point was fairly clear. Given that effect you would find that 41% of prius drivers, most of whom got far bellow expected mileage still bought hybrids. We would expect the population of prii post 2008 to be more likely. The tdi in 2004 had an old epa of 41, and got 45.5 on fueleconomy.gov. Compare Side-by-Side

 

Toyota makes an excellent diesel - it just isn't available in the United States. The Hilux is without a doubt one of the best vehicles made. It may not get the milage of a Prius but "You can’t underestimate the value of having a vehicle that is fast, will never break down, and is strong enough to mount a heavy weapon in the back."

Why Rebel Groups Love the Toyota Hilux - Newsweek and The Daily Beast

 

I don't know if there are any production diesel engines using Miller / Atkinson cycle.
The distinct feature of the Miller / Atkinson cycle is an expansion stroke that is longer than the compression stroke. The classic design features a complex crank. This means that you get a nice, long turn without the same compression losses.
The Miller/Aktinson cycle engines that we drive have a conventional crankshaft but keep the inlet value open much longer so that compression starts late, whereas the expansion value timing is normal.
A smaller compression ratio also means that you don't have to use high octane to avoid pinking/pinging. If a conventional engine had a 13:1 compression ratio it would need avgas and an additive of some sort.
Since diesels already have high compression ratios and loads of torque at low revs, a supercharger or electric motor boost at low revs is not filling a hole; unlike a small petrol engine that develops power and torque at much higher revs. A turbo helps a diesel engine breathe. In a diesel the timing of the fuel delivery is key since there's no spark to ignite. Direct injection using very high pressures has recently moved from diesels to petrol engines, enabling the much higher compression ratios on standard fuels that we see now.
Diesel engines have a long stroke to begin with. Old-skool diesels had compression ratios of 20-22:1 and needed glow plugs to start and a cool-down (known as "dieseling") to stop. Modern diesels generally start immediately, but benefit from a bit of a pause before cranking. New diesels tend to be 16:1, however the Mazda SkyActive diesels are 14:1 and are able to greatly reduce NOx emissions, though not as low as petrol.

Anyway, the Volvo V60 PHEV is better.

 

It does not make much sense in a turbo di diesel for automotive applications. You are going to make your compression with the turbo, and a variable geometry one, and properly used waste gate can nicely regulate it. Since diesel needs the compression to ignite the mixture, you don't decrease it with late intake valve closing. A turbo di diesel can burn vary lean, unlike gasoline. To reduce pumping losses, the idea in miller/Atkinson you can decrease native compression and mazda is doing this in the skyacitv-d. Part of the pumped energy is recaptured by the turbo charger, so the main reason to reduce compression is lower NOx.

It appears GE has a 4 stroke turbo di diesel electric locomotive that uses the miller cycle. It does claim that the design improves efficiency and reduces NOx. The most efficient diesels are 2 stroke, low rpm turbo di ones used on ships.

 

The sentence with "euphoria" didn't make a lot of sense. If I have one good pair of shoes, I don't need a second, identical pair. But I might need some running shoes or work boots. Thus having a successful single model Prius justified expanding the Prius family to provide a 'Prius c' and a 'Prius v' . . . models with distinct advantages.

In our case, we had a 2003, 1.5L, compact commuting sedan so adding a 1.8L 2010 gave us a Prius with more storage, higher speed efficiency, and we kept the 1.5L for daily commuting. For us the 2003 Prius is functionally equivalent to the 'Prius c.'

Our 2003 Prius, bought in 2005, started with an EPA metric that was changed:

	Column 1
0	[tr][th]City[th]Hwy[th]Combined
1	[tr][td2]52[td2]45[td2]48
2	[tr][td2]42[td2]41[td2]41

Source: Fuel Economy

So my first drive from Fort Worth to Shreveport gave 39 MPG at 75 mph, not even close to the 45 MPG of the EPA rating. So I continued the subsequent segments at different fixed speeds and plotted mph vs MPG. Charts like these are found in the aircraft handbook as it is not wise to run out of fuel while flying. The 52 MPG 'knee in the curve' at 65 mph remains within my performance expectations.

Personally, I think every Owner's Guide should have a chart with mph vs MPG and two curves:

1. MPG on a standard day, no accessories, no lights.
2. MPG on a freezing day, maximum heater, lights, all accessories.

"Your mileage at a constant speed on a flat, 10 mile concrete road, is measured to fall between these two graphs. . . . " Simple, neat, and all the EPA testing nonsense, except for CAFE, goes away.

Bob Wilson

 

I am not quite understanding where your argument is coming from. The data is from people trading in prii, not keeping them, that would be a different distinction. Whether you call the prius c, a prius or an aqua makes no difference, it expands hybrid choice, in a market growing way. I suppose if you want to go with the branding you could just as easily name the camry hybrid, prius s. As I said in my comment, more choice in hybrids that sell should increase retention. Again, lack of competitive models in 2011, is one factor in looking at the 41% as a good number. If you think the number is very low, there must be some euphoria with the prius, thinking it is a much better car than it is.

Again, I hope you can understand, that if you paid extra to get 48 mpg, and have a more typical drive, a large number of owners might be disappointed. Most of us don't just go on the highway at 65 mph cruise, or drive the number of miles you drive. Again this makes the 41% look like a good number, when facts are taken into account in context. The epa changed the test to account for higher acceleration, heat, and cold. On a cold day driving 7 miles on the highway, you simply can't expect 52 mpg. YMMV

As discussed on a different page, this is not a bad suggestion, but most would be quite disappointed with mileage compared to that. A websight that you can pop in your google maps route, might be something cool for manufacturers to implement. That could account for some of the real world variables.

 

Question:
Are there any families on PriusChat other than my wife and me who have BOTH
a Prius (or other hybrid)
AND
a Diesel?
(In our case, a 2010 Prius II and a 2012 Audi A-3 TDI).
I just have this intuition there ought to be more. E.g., the hybrid for town, the diesel for long highway trips.

 

When I was in Nepal in 1991 on a Fulbright, I was occasionally able to ride in a Toyota LandCruiser, which is also namechecked in the article. I think it was a gas model.
An amazingly good vehicle for terrible roads. And non-roads.

 

Probably most European members. Well apart from me; we have two petrols - a small one for town and the Prius for the highway trips

 

I traded my Mercedes E class turbodiesel in for a Prius.
The Merc was a very nice car but I payed 150 euro's road tax every month.
That's close to US$ 200.
I didn't make enough km's to make up for the slightly lower fuel price.
The gov't here wants to promote green cars, so now I don't pay any road tax.
I don't care about the "status loss" ....
There are nicer things that I can do with the saved money, than paying for how other people might look at me for what I drive.