Fiat’s current management loves diesels. Or used to love diesels. It was hybrids they didn’t like. But they’re moving into hybrids anyhow because they couldn’t fit the emissions gear for diesel into anything smaller than a Jeep Grand Cherokee. The RAM pickup trucks, for example, have a 14 gallon urea tank. Yeah, find a place for that on a Fiat 500, already…
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I thought part of the problem on the 4 cylinder VWs was that they had no urea system and potentially adding one was one of the big delays in coming up with a fix.
I just knew it had to be a stupid question.
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Ooooh, I usually just roll my eyes at those people, but if they are doing damage to their vehicles I might change that to a little smile.
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At the time I was actually involved with FIAT they did not like Diesels for cars and were buying them in. Toyota and other Japanese manufacturers have also had to fit third party Diesels into cars for the European market, which is how I once had a Japanese car with a Mercedes engine. The story of the rise and fall of Diesel is going to be a very interesting part of engineering history. Early cats hit the fuel consumption of gasoline engines very badly, but were pushed by FoE, who didn’t seem to see that getting lead out of gasoline was highly desirable, but thereafter, outside California, there were more economical solutions like lean burn, which produced more running pollutants than cats did but warmed up faster and so produced less pollutant in the first mile, which is usually in urban areas.
When fuel consumption got important, the gasoline engines of the time were using around 40% more fuel than an equivalent Diesel because nobody had cared about it. So Diesels got very popular in countries like France which had next to no oil reserves and used taxation to encourage economy.
Eventually we got the turbocharged small capacity variable valve timing technology which gives good fuel consumption with gasoline engines, around the same time that, to meet new environmental standards, Diesels were needing not only cats but particulate filters and urea injection. A number of companies now make 900cc-1l 3 cylinder gasoline turbos that produce up to 130BHP/litre and are much cheaper than Diesels of a similar power output; they just need CVT or more gears in dual clutch to cope with the torque peak. FIAT have put a lot of effort into this and their Twinair design is very advanced.
We can assume that this trend will continue until either fuel cells* get cheap or someone comes up with a cheap way to detoxify and remove particulates from Diesels. I wouldn’t bet on Diesel winning this time.
*Enkita’s Law: Any sufficiently advanced rechargeable battery is indistinguishable from a fuel cell.
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Particulates are pretty easily handled by the particulate filters attached to modern diesel engines, and LPG has some significant problems (density and the cost and weight of the fuel tank) on smaller / cheaper vehicles. Or as the plug-in hybrid folks say, burn the LPG in the power plant, not the car. As far as efficiency goes, any efficiency improvement that works with a gasoline engine would work with a diesel engine too. Want a hybrid? A hybrid diesel would make a Toyota Prius’s gas mileage look lame. The deal being that high compression will always have a better expansion ratio than low compression, and there are limits on what you can do with gasoline even with GDI because its autoignition point is so low.
On the other hand, with plug-in hybrid technology now off the drawing boards and in hundreds of thousands of people’s driveways, for day to day driving the advantages of diesel are utterly lost. Most people don’t drive 100 miles a day to get to work and back, they just need the higher energy content of a liquid-fueled engine for longer / rarer trips, and hauling around the extra weight needed for the higher compression of diesel would impact the vehicle more than the lower efficiency of a lower-compression gasoline engine. I don’t think it’s a coincidence that Chrysler’s new Pacifica is going plug-in hybrid rather than diesel… that is a tightly packed vehicle and there’s just no room for DEF tank, twin turbochargers, particulate filter, etc. needed to make diesel work, and putting a heavy lump of iron diesel engine over the front wheels would have adversely affected handling while not giving any of the advantages of plug-in hybrid technology (specifically, zero emissions for most trips and high efficiency for most trips).
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To be fair to these people, volcanoes are pretty bad polluters too. But volcanoes have been around for billions of years and, if they notice us at all, do so only as a very minor irritant. Doing what they do doesn’t risk their own eventual extinction.
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Karma that slow doesn’t pack quite the punch. Maybe re-route the exhaust into the cab?
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Real karma would involve their not being allowed to drive anything other than a Mk.1 Prius.
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Hybrid Diesels have numerous problems - weight, complexity, maintenance cost for starters. If you listen to a gasoline hybrid when the engine is started it makes very little noise. That’s because you can vary the valve timing to give very low compression at start, so very little power is needed to get the engine turning and the take up of power from the electric motor can be extremely smooth. (The same trick is done with non-hybrid stop-start engines.) But for a Diesel to start it has to compress a full air charge and turn over fast enough to get the air temperature high enough for ignition - so a lot of power is needed for starting and, if it happens at the same time that the electric motor is running, there is always a jerk. The added cost just doesn’t bring any benefits to “normal” drivers.
But, even worse, the whole point of a hybrid is that the electric drive means that when the IC engine is turning, it turns at optimum power and rpm for efficiency. The biggest disadvantage of spark ignition over Diesel is poor efficiency at idling and low speed. And in a hybrid, the engine doesn’t run under those conditions. It is either off, charging the battery or both moving the vehicle and charging the battery, so it’s at its most efficient. And it can be designed for efficiency because it doesn’t need an acceleration boost capability - that comes from the electric motor. As a result, the improvement in fuel consumption for a Diesel hybrid is likely to be not worth it, it’s just that in many jurisdictions Diesel fuel is sold significantly cheaper than gasoline to keep truckers happy.
I don’t drive a Prius these days because it doesn’t meet my operating envelope. But the inventors and designers of the Prius were geniuses; they came up with a design concept that had enormous potential, and they made it work far faster than the gasoline engine or the Diesel engine were tamed to road vehicles.
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I thought diesel prices were, if not cheaper, less variable than gasoline because companies that depend on diesel ensure a robust futures (or swaps) market.
Nobody seems to be too interested in keeping truckers happy.
Diesel fuel tax rates in Europe are generally lower than for gasoline. What’s more the tax is per litre, whereas Diesel has a significantly high density than gasoline, so the effective duty per Joule is lower still.
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