2017 F-350 DRW 0-60 testing

Adam R wrote:

4x4ord wrote:



The typical diesel engine in a pickup is only around 35% efficient. I'm thinking there's all sorts of room for improvement. For instance nothing is presently being done to harness the heat energy in the cooling system. Think of all the energy lost going down hill and braking. More can be done to reduce areodynamic drag on the fifth wheel RV.

Not sure where you are getting that figure. 25 years ago when I did my mechanical engineering undergrad, diesels where in the low 40's....about where they are today. Yes, you can get them into the low 50's, but is usually in lower rpm engines, ships being an example.

30-35% is gasoline engine territory.

To extract meaningful work out of two temperature delta's you need them to be as far apart as possible. 200 degree air opposed to 70 degree ambient isn't enough to fool with for energy extraction. Regenerative braking is cool, but now you are carrying around a few hundred pounds in batteries everywhere you go and those, and the corresponding technology, adds cost to your vehicle. Those additional costs can buy a lot of diesel fuel to offset the marginal 5-10% gain you might achieve.

As I said above, it's all about compromises. If there was a breakthrough or disruptive technology, I think we would have already seen it by now.

Adam

I don't know the exact level of efficiency that a diesel engine might run at while pulling an RV down the road at 60mph. I'm sure it is not in the low 40's. 35% is likely too high. I could see a diesel truck engine running 40% efficient when working hard at a low rpm