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World's Only Diesel-Electric Honda Insight
Jake Staub writes "Just replaced the gasoline engine in a Honda Insight with a Diesel engine. On a 3,000 mile cross-country shakedown journey the car averaged 92mpg over 1,800 miles. Around a very hilly town in Northwest Washington, the car is averaging 78mpg. These mileage averages are without the electric side of the vehicle fully functional. With a bit more tinkering on the electric side and through a slight gearing change through tire size, it is anticipated that the car will likely average 100mpg. The build for the car has been documented on the web site and is as close to open source as my time allows. The car was built by two guys in a garage in Southern Maryland. If we can do it I don't see any reason why major auto manufacturers can't do it since we used their parts."
The black helicopters need to be sent in here. Gas Mileage like that is un-American. Before you know it, the schematics for the water-car will get out.
(whisper)When it comes to cars, the slashdotter species generally has absolutely NO idea what it is talking about. Shhhh. Here comes the posters now. Let's watch quietly as they trot out the same old ignorant meme's about hybrids, electrics and diesels.(/whisper)
By using less fuel you are shifting the tax burden onto those who cannot afford a high tech vehicle. We should expect owners of hybrids, electric cars and high efficiency vehicles to pay their fair share if they can't manage to pay their road tax through fuel purchases. Perhaps you people should be required to keep a log of your travel distances and cut a check when you renew your state registration based on your mileage.
“Common sense is not so common.” — Voltaire
No, modern diesels are nothing like the anemic POS that GM released in the 70s. Mainly because of the addition of the turbo charger (which diesels benefit greatly from), but common rail, higher injection pressures, advances in metallurgy.
My TDI is quite peppy, mainly because the shape of the torque curve. BMW has a 335d and X5 which they are selling here now. VW and Benz have been selling diesels here almost non-stop since the 70s.
That's why I always laugh when Chevy's ads come on trying to sell me this AMAZING 29 MPG car.
I got 48 MPG in a '86 IDI Diesel (that was a bit weak, but who needs more than 50 HP?)
I get 45 MPG in a '98 TDI diesel that is quite peppy. I have upgraded injectors and a special chip tune. I bet I'm just barely over 110 HP, if that.
Diesel engines have always been where hybrid cars should go, its just that in North America, most people avoid diesel and gas stations often don't have it.
Diesel engines afaik have always been more tunable to run very efficiently at specific speeds and are therefore a much better choice for generators in general (and are often used in that capacity). Using a fixed-speed diesel engine to generate electricity for a hybrid vehicle seems obvious, and its been done for both city buses and the military HMMV with great success.
I believe a consumer focus on gasoline has lead to car companies' focus on gasoline-electric hybrids instead of diesel-electric.
- Michael T. Babcock (Yes, I blog)
Well, the big issue was diesel was much dirtier in North America (high sulfur content) than in Europe, and a lot of the technologies that make diesel cars behave like gas cars tend to require the clean diesel. These days though, I believe the legislation has made low-sulfur diesel mandatory, which is why we see VW and Mercedes starting to import more diesel cars.
Quite a change, really - drive a heavy SUV that gets 5L/100km or better (probably spewing less CO2 than the little car next to you...). Or the fact that the engine lacks the traditional diesel clatter normally associated with trucks, or hell, doesn't Mercedes have a thing that mixes ammonia or something with exhaust that makes the exhaust even cleaner still?
The main reason gasoline hybrids get better mileage than direct-coupled engines is that the gasoline engine is not forced to operate at inefficient points on its' BSFC map (near closed throttle). The engine only runs when needed, and then it runs near its' BEP (Best efficiency point), or occasionally at maximum power which also has decent efficiency. It is not forced to idle and off-idle conditions where the pumping losses are horrible and efficiency s#x (5x fuel for same marginal power).
Diesel engines have entirely different BSFC maps, and do not suffer the same pumping losses (vacuum across throttle plate). Their drop off at idle is _much_ lower than for gasoline engines, so they're great in city-wide European traffic jams. Diesel fuel also is ~15% denser (more heat per gallon) and the higher compression ratio is about 5% more theoretically efficient.
But a diesel hybrid does not have much to gain by hybridization. The BSFC map is much flatter, and the engine restarting power & wear is considerably higher.
All diesels in the 70s where gutless. Heck simple truth was all cars in the US in the 70s where pretty gutless. The 70s was when we where trying to get emission controls to work and computers for controlling fuel injection and spark where primitive or just not available.
This is true. The basic scientific research on how to control automobile exhaust emissions was incomplete at the time, and the engine controls available were too primitive. This isn't anyone's fault - technology just hadn't caught up to the needs of the time. The only way to do it was to lower compression ratios, and reduce the camshaft profiles. The pellet-bed catalytic converters of the time were horribly restrictive also. About the only good thing that happened to car engines in the 1970s was the advent of good electronic ignition systems. Turbochargers were not in wide use (or production) for cars, so there were very few turbodiesel cars (mostly MB) due to the cost of the turbo itself. Normally aspirated diesels aren't exactly exciting to drive. (Trivia - when the Porsche 911 Turbo came out, parts of the turbo system were made by Lycoming, the aircraft engine company, because there weren't any suitable automotive turbo parts available.)
GM got such a bad rap on the diesel and for the most part it was unfair.
That's not totally true. There were some basic design mistakes, and a cost cutting decision you mentioned that were the downfall of the Oldsmobile diesel.
The GM diesel where sold to people that didn't know how to maintain them and by dealers that really didn't know how to maintain them. People that bought a 300D where used to paying Hans the big bucks. Olds buyers where not.
Actually, a Mercedes diesel of the time required very little maintenance (on the engine at least). Oil, coolant and filter (air/fuel/oil) changes, and that's about it. You could do it all in your driveway.
Also GM didn't put in a water separator. That was shouldn't have been an issue but right then quality of diesel went to crap and you had a lot of failed injector pumps. Again MB was used to crap fuel and put in the extra filtering needed.
This was a big problem. All diesel fuel accumulates water eventually. Diesel fuel has a lubricity requirement - because it must also lubricate the high pressure injection pump. Water is not a good lubricant. Leaving out the water separator was a cost cutting decision GM would not repeat. The later Chevrolet (designed in collaboration with Detroit Diesel) 6.2/6.5 V8 came with one, and even a warning light on the dash to indicate that there was a buildup of water in the fuel (you would then have to open a valve and drain the water out of the separator.
The problems weren't all maintenance-related. The GM 350 diesel (and the lesser-known 4.3V6 diesel used in the front-wheel-drive A-body cars, unrelated to the later Chevrolet 4.3 gas V6) was designed by reusing parts from the Oldsmobile gas V8. The blocks were made using a high-nickel iron alloy and are very strong - they're often bought from the junkyards by drag racers who want to use them as the basis to build very high powered gas engines. The cylinder heads and crankshafts were pretty much stretching the design limits of the materials they were made of, since they were designed under budget constraints. Cracked heads and broken crankshafts were not uncommon. There are tolerances in the alloy compositions (this is just a fact of life, not a GM problem) - because of this some engines got stronger crankshafts and cylinder heads (basically by chance), and there are quite a few 5.7 diesels still running around. I have a friend who was driving a 1980 Oldsmobile 98 Diesel until a few years ago when the body started to rust out.
The later 6.2/6.5 engines were very durable, because they were designed from the ground up to be diesels.
It is unfortunate that GMs design errors stained the diesel in the US
Putting moderation advice in your