# Diesel-Electric Big Rigs? **URL:** \ **Category:** Factual Questions\ **Created:** [March 17, 2001, 4:43pm UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384 "2001-03-17T16:43:02Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [March 17, 2001, 4:43pm UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/1 "2001-03-17T16:43:02Z")
Modern Locomotives operate with a diesel-electric drivetrain, for efficiency. Lately, they are making gas-electric hybrid cars. Why didn’t they build diesel-electric 18 wheelers? I figure, an engine, generator, and an electric motor in each wheel-hub would be moderately more efficient(not to mention far easier to drive)than clutch and who-knows-how-many gears. ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [March 17, 2001, 4:52pm UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/2 "2001-03-17T16:52:55Z")
This was covered in a VERY recent thread: [http://boards.straightdope.com/sdmb/showthread.php?threadid=63293](http://boards.straightdope.com/sdmb/showthread.php?threadid=63293) ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [March 17, 2001, 7:02pm UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/3 "2001-03-17T19:02:27Z")
Not exactly. Then other thread touched on the subject, but I don’t see a _conclusive_ reason why trucks are not diesel-electric. (My guess would be either overall weight or else that the diesel-electrics would have a hard time on steep inclines.) I know the Army asked the U.S. automakers to try a diesel-electric system on the standard 2 1/2 ton 6×6 around 1970 and it was shown to be not effective (using 1970 technology and costs). The huge dump trucks used in open pit mining (the ones where a baskeball player has to look _up_ to see the wheel hub) _are_ diesel-electric, but you’ll note that the grades inside a pit mine are never steep. ---
**Author:** ![Gunslinger](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)\ **Post date:** [March 18, 2001, 12:29am UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/4 "2001-03-18T00:29:56Z")
> [@](#): > > \*Originally posted by tomndebb \* > \*\*The huge dump trucks used in open pit mining (the ones where a basketball player has to look _up_ to see the wheel hub) _are_ diesel-electric, \*\* As are the giant front-end loaders, etc. They’re made right here in my town! 🙂 Each wheel has its own motor (the whole wheel motor thing was invented by Mr. LeTourneau, who then founded the manufacturing company and the college here). ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [March 18, 2001, 4:29am UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/5 "2001-03-18T04:29:55Z")
> [@](#): > > \*Originally posted by tomndebb \* > \*\*Not exactly. Then other thread touched on the subject, but I don’t see a _conclusive_ reason why trucks are not diesel-electric. > \*\* Quite right. I was engaging in the kind of anal whinging and pulling apart of other people’s threads of which I am so often critical myself. Apologies. :rolleyes: ---
**Author:** ![Anachronism](https://avatars.discourse-cdn.com/v4/letter/a/e56c9b/32.png) [@Anachronism](https://boards.straightdope.com/u/Anachronism)\ **Post date:** [March 18, 2001, 3:26pm UTC](https://boards.straightdope.com/t/diesel-electric-big-rigs/58384/6 "2001-03-18T15:26:12Z")
Actually I asked this question in that thread and didn’t get an answer, perhaps I should have started a new thread. **TheLoadedDog** --The [SDMB CoPs](http://boards.straightdope.com/sdmb/showthread.php?threadid=61735) are going to have to come confiscate your flashing light **and** utility belt ;). I have been thinking about the OP for a few days now and have come up with a few WAGs. Not much opportunity for regenerative braking since trucks travel at a constant speed for long periods of time, but this applies to trains also. A train has a very low power to wait ratio (I think), acceleration is not really an issue. Perhaps this system is most efficient for vehicles with a very low power to weight ratio and/or operate at very low speeds for an extended periods of time. > [@](#): > > Why didn’t they build diesel-electric 18 wheelers? \ and who-knows-how-many gears. Ten speeds in most trucks, but you are shifting into seventh at 30 MPH.