That Wikipedia article pointed me to this one, which mentions a Doble E19 which ran “10 to 14 miles per gallon on fuel oil”. I pondered that statistic for a bit, having no idea what mileage other cars of that vintage were getting.
Then I realized that this thread had wandered quite afield from the OP. The OP asked why steam-powered cars of any fuel lost out to gasoline-powered cars. That morphed into a question asking what fuel was used to boil the water into steam. Somehow, I focused too much on the inefficiency of wood burners, and I apologize for that.
Keeve the link to the Doble car was provided right back at the beginning, and then referred to several times after that. Anyhow, apologies accepted.
Note that the Wiki Doble link says that it was as economical as cars of its day. So while 10 to 14 mpg sounds freakin’ awful, you have to compare like with like. I don’t know whether a steam car could, with 70 odd years of intense development, have ended up being as economical as a modern car, but it’s an interesting question to ponder.
10-14 MPG equals or beats cars built in the decades after Doble ceased production. Many cars built well into the 1970s averaged around that much, and some of the larger SUVs as well as high performance sports cars still clock in such numbers, and they have the benefit of aerodynamics!
Nor do we have to completely wonder what steam cars could do with 70 years of improvements. Hobbists have tweaked their steamers to improve their performance, and I imagine that improvements in burner design for things like gas/oil furnaces and water heaters could easily be adapted to a steam car.
I am, sorry. I didn’t notice that he didn’t actually link. Also, the OP (I guess) intended to link to the Wiki page on steam cars but he accidentally mucked up his link. The Wiki page certainly mentions Doble cars. The link provided by yabob at #14 goes to an SDMB thread which also mentions and links to info about Doble cars. Nonethless, I apologise, I thought there were direct links provided.
If you run the numbers to convert units, that means that wood is about 3.38 times more energy-dense. (gas density: 737.22 kg/m3) That’s a difference, but it’s not an enormous difference. That Yugo is a home-grown project. I have no doubt that if any car companies started working on that problem they could greatly improve that system and get rid of most of the detrimental aspects. Yes, burning wood gas isn’t going to replace regular gas, but it’s interesting that such a weird system is even viable at all. And, as you later noted, it doesn’t have anything to do with steam engines, it’s just a tangental issue of alternative fuels.
It was never about steam engines not having enough power. It is only recently that individual diesel locomotives became comparable in power with the articulated big boys of steam, like the Allegheny or, well, Big Boy. But, if you can just gang together a slew of efficent lightweights with the same crew as the single steam engine and you gain greater flexibility and easier maintenance, the superlocomotive really has no advantage over a string of diesels (where it would over a string of steam locomotives).
Well, it would need to be sized for the worst case: fully loaded vehicle climbing a steep grade on a really hot day (say, 42 degrees C). I don’t know a quick way to do the calculations, but you’re looking at needing a lot of surface area and airflow. If you want to get by with a modestly sized condenser, you might need some truly ferocious fans (which themselves add weight, bulk, expense and power drain).
Wouldn’t it make more sense to have a multi-part heat exchanger? Once things get beyond a certain limit, pop open a valve and activate a second radiator matrix. That way you would have one optimised for normal conditions and still have the ability to deal with extreme conditions.
Most steamers have, in addition to a condensor, a heat exchanger (IIRC, they refer to it as an “economizer”) that routes the exhaust steam through a heat exchanger that dumps the heat from the steam into water flowing into the boiler, so the boiler has to do less work to get up to operating temperatures. Depending upon where you have the water tank in relation to everything, you could also route a steam line through that. So long as the water remains just under the boiling point, you’d be okay.
One other benefit to steamers that hasn’t been mentioned is that a steam engine is “free reversing.” You can reverse the flow of steam through the engine and it’ll simply slow things down, rather that breaking it, like it would on a gas engine. This would save wear and tear on brakes. I don’t know if any cars were built with this feature or not.
ONE THOUSAND POUND FEET OF TORQUE?!?!? Excuse me while I try to get my jawbone back where it belongs. (shaking my head) All that torque put into 1925 tires, too.
For busting snowbound passes in the mountains, it has only been rather recently that the (IIRC) Union Pacific( ? ) quit using the big steam engine to open the line.
Also remember, (IIRC) that a steam engines maximum torque is at zero RPM and that can be quite advantageous.
I have read that a Model A Ford is about a 15 mpg car. Wikipedia says 20-30, but I think that’s extremely optimistic for an engine that used 200 cubic inches to produce only 40 HP.
Yup. I may be wrong, but I think that there might be a size advantage to steamers in relation to HP, with an electric motor being larger and heavier than a steam engine of the same HP. In both cases, however, the massive amount of torque that they put out enables vehicles powered by them to use smaller HP engines.
