Towing rpod 192 - Event Date: 28 May 2020 - 30 Jun 2020

The OP may wonder what sort of wasps nest he uncovered!

Just for the record, virtually all class 8 OTR semis that have been made in the last 30 years or so are using a turbo charged 6 cylinder inline diesel engine (various brands) other than the occasional experimental hybrids or electric prime movers...etc....but pretty much all commercial OTR class 8 units hauling freight...more or less. Probably 99.999 percent. Just sayin.

But that is a larger, relatively slower turning turbo with well-proven technology, and equipped with engine braking.

My primary concern with the new generation of gasoline turbo engines in trucks used for towing:

How effective is the engine braking? 

OTR trucks running turbo engines nearly always have some sort of engine brake.

I've not heard of such a thing on gasoline turbo-equipped engines, unless they have some sort of automatic exhaust brake. When coasting down a long downhill grade with a 5,000 or 10,000 pound trailer pushing the entire rig towards the lowest point on the road on a long steep grade, you WANT at least SOME engine braking so your disc brakes and electric trailer brakes dont turn into red-hot smoking pools of useless molten metal. 

Normally aspirated engines always have a good amount of engine braking on tap, available by simply downshifting one or two cogs. Turbos do not. Not unless that engine has some sort of supplemental system for engine braking. I do know that some gasoline turbo equipped engines have variable valve timing, and that may be able to be used as an engine brake. But I have heard no mention of it, nor have I driven a gasoline turbo engine in the mountains with a heavy trailer.

After all, when pulling a trailer in the mountains, GO power is nice, but WHOA power is a necessity.

Or so it seems to me.

(BTW I have about 3 million miles of diesel truck driving experience, including all US mountain ranges...so I know a bit about the topic of pulling heavy trailers in the mountains)

Tow/haul mode is the setting that enables the vehicle ECM or PCM to make use of different shift points, but that in itself does not slow the vehicle during a descent. Its the performance of the engine when the fuel flow is cut to zero (or nearly zero) and the intake or exhaust air to or from the engine (or its individual cylinders) is reduced or restricted, that actually provides 'brake horsepower'...which is what actually retards engine RPM.

I think what you are missing in your point is that we don't need to have enough level 3 charging stations to replace all the gas stations immediately. Put another way, your are likely right that it will take 25 plus years for the entire fleet to be converted to electric (if it ever does). What we need to have by 2025 is sufficient charging stations dispersed adequately to get everyone to consider an EV at their next purchase. There will be early, middle, and late adopters that will spread out the transition, and even then only when they need to change. A vehicle isn't a cell phone, most folks aren't going to have the dough to dump a perfectly good vehicle just because they want the coolest new thing. 

Not true at all about the hybrid. The hybrid drive has far less moving parts than a normal auto trans, about 10%. It is basically a planetary gearset with the two motor/generators integrated into the transmission allowing them to rotate in both directions under electronic control to create a continuously variable trans. It sounds complex and the software is, as are the various power flows, but the rotating hardware is dead simple. BTW there is no starter in a Prius, one of the motor-generators does that job, another simplification. 

 Also, it babies the ICE, which is allowed to warm up while the motors drive the car, and the ICE is never hammered. You can flog a Prius on mountain roads and the motors take the beating, the ICE torque demand and rpm changes are always muted. Takes some getting used to the sounds but it works just fine. And, to podwerk's point about braking, you can normally drive so you hardly use the friction brakes, the motor/generators do all the braking while recharging the battery. 

That is not the case with long downhills with the standard non plug in Prius though, once the small battery is recharged there is no place for the energy to go except engine braking, (there is a selection for that on the "shifter") which isn't great, because the engine is quite small. That's where pure EV's with big batteries come in. If you look at the youtube report on the Tesla X towing on the Ike Gauntlet it is the only vehicle they ever tested there that needed zero friction braking. Just set the cruise control and watch the charge level go up. 

Anyhow the proof is in the pudding with the Prius, they routinely go half a million miles in taxi service, which is rough for any vehicle. Many places you go now its hard to find a taxi that isn't a Prius. They replaced the Crown Vics, another solid and reliable vehicle, but not nearly as durable as the Prius. And yes, being the conservation guy I am I waited for the gen 3 Prius before I bought mine.  

As for the F150 EV, there is zero reason to think that if the vehicle empty goes 500 miles on a charge that it will only go 150 towing. Do the math. If you get 24 mpg empty and 14 towing in the gasser, a ratio of 58%, then we should see the same ratio on the electric version. Same aerodynamics and rolling resistance so same hp demand, whether it is coming from an electric motor of an ICE. We have no idea what Ford will actually produce, but something around 40-50% range reduction should be expected when towing, just like with an ICE.