As stated in the other thread, I hauled 1000lb pellet load three time today in 56 F weather. I also made several trips up a "stated" 11% grade 5/8 mile long hill in an attempt to see if electric assist was possible with a heavy load. My "limited" data indicated yes electric assist was possible the complete lenght of the uphill if SOC was greater than 53% at the start (bottom). Prior to this quick study, I was not sure if this type of load would "wear down" the SOC below 53% prior to my vehicle getting over the top. Note: I did not start with the exact SOC on the two trips that yielded electric assist but both were above 53%. I also attempted to keep the horsepower above 50 on each of these trips in an attempt to somewhat equalize the "resistance".
Photos from the 1st uphill adventure with a 1000 lb load:

this was two blocks from the start

this was on the meat of the uphill

Photos for the 2nd trip up:



Again this was taken on the meat of the uphill

Photos from the 3rd trip uphill

this was taken 2 blocks from the start


taken on the meat of the uphill

Thoughts: this little report will not pass the criteria for "true" research but indicates the value of exceeding 53% SOC if one feels having electric assist is important when hauling heavy loads. This author admits to using the downhill of this hill to build SOC greater than 53% prior to each uphill run test. This author can not speculate on how long electric assist will last on uphills with this load and is not interested in driving 75 miles east with this type of load to test on a six mile uphill found on the Pa. Turnpike or Rt. 22. Maybe someone else can try towing their trailer on a long uphill and report (with photos) back to this site with their results.

 

Billy, I'm confused at what you were trying to measure here.
If the engine was on, then there too many variables.
What were you testing?

Your real test should have been the FEH's ability to go up the hill in EV mode.
( Which I think would have been totally possible at 15 MPH and under. )

I have towed a 2000 pound trailer up a 6% slope in EV mode.
Towing that trailer at 55 MPH my FEH used assist on every little camel hump in the road to the point after a couple of hours of interstate, my HV battery was over 86 degrees and turned on the A/C for it.

 

Good info.

The question I am looking at is: Can the FEH, while towing, climb a long hill at highway speeds?

What I consider highway speed is 55-65. My criteria for a long hill is a 7% grade on I-64 in West Virginia that is about 5-6 miles long and a very steady grade.

I have little doubt that the FEH can climb a steep grade short enough to not deplete the battery. Electric motors are power plants that "just keep on giving and giving (or more correctly pulling and pulling!)," at least until something melts in them...

But, if you are on the highway and towing, if this 7% & 5 mile long hill calls for full engine output power plus traction motor power to keep up with traffic flow, will it make it without pulling over to charge the battery?

I suspect that part of Ford's towing limit criteria has to do with this scenario.

Any experience out there like this?

 

There was a poster in the past who drove his FEH with a 15ft Shasta trailer from Kansas City to Washington DC. This included over the hills of West Virginia. He initally stated the trailer was around 1500lbs and reported his RPM's were at or in the low 4000's range during his trip in West Virginia. He later reported back to this site last year he had the trailer at the truck station and found out it was nearly 2500lbs! I will have to dig out my old papers to see if I have a paper copy of this report or do a search here.

John, you are correct in that the report--I should have referred to it as an observation--is somewhat confusing with multiple variables involved. In short, I was attempting to see if I could climb the length of this hill with electric assist while keeping the horsepower above 50 via scanguage II and the rpms at or below 3000. I did this in a real world condition with traffic flowing in all directions and with a posted speed limit of 35mph. My observation revealed I could enable and maintain elelctric assist on this hill with this load if the SOC was above 53. At no time did my scanguage II horsepower read much over 61-so I did not max out my ICE capabilities. I did hit 18 mph Electric mode travel on level ground once with this type of load.

Here is a question for others:
My question is whether electric assist will be enabled (if it is below 52 SOC) on a long uphill or with heavy loads if the vehicle's ICE is being stressed beyond a certain level? For how long and at what level of assist can one expect electric assist? I have read of 10 seconds with 40 horsepower electric assist or 40 seconds with 10 horsepower electric assist in the past. Is this still true or does it need to be explored further with questions on towing capabilities raised in the immediate past.

 

Look at this post from the past about the Shasta trailer:
04-18-2007, 09:05 AM
Hybrid_SUV
Hybrid_SUV_Owner
Hybrids: '05 FEH AWD
Posts: 134


Re: Trailer towing impressions...
Hey everyone,
Last week I bought a 14ft Shasta camper trailer that weighs approx. 1500lbs. Towed it from Omaha-DC with the FEH. Biggest issue I had was wind resistance at speed. There were 35kt winds in IA...almost a headwind. At times, I could not go above 55mph without redlining the engine. I tried very hard to keep the rpms below 4500.
In Ohio....with the headwind gone....I maintained 55-60mph fairly easy...with the engine settling at ~3500rpm on flat ground.
I didn't have any issues with a UHAUL trailer....1800lbs...so I really think most of the probs were due to wind. Oh yeah, just had to be real careful in the App mtns....up the hills (+7% grade) I just hugged the right lane and held rpms no higher than 5k.
MPGs ranged from 12-16.
I know the CVT revs a lot....but 5k seems unnerving to me...is there anything wrong with 4500-5000k for an extended amount of time?
No issues at all with speeds below 35mph...even in traffic. No probs whatsoever with braking or accel...as long as you take it easy and don't do anything stupid.
Clarence, I know you tow a lot...anything to add?

Nate

at this link: https://www.greenhybrid.com/discuss/...ressions-9226/

 

Good post. I infer from it that the FEH will do well towing.

But... it doesn't address my core issue of the "long" hill climb.

Anyone out there got some info on long hill climbs?

 

Your e/CVT REQUIRES a significant level of input power, ELECTRIC input power, to "match" (~3:1..??) the power of the engine. On a long pull such as you describe, requiring FULL engine torque to sustain the desired speed, I have little doubt that the battery would soon be depleted. At some point nearing full depletion a portion of the engine torque would begin to be used to supply electric power to keep the e/CVT operational.

So your roadspeed could not be sustained.

 

I have climbed long 7% hills towing 2000# in the Rocky Mtns.
I was able to maintain 55 MPH with high ~4500-5000 RPM's for as long as needed.

The Horsepower displayed on the ScanGauge was 75 to 80 HP most of the time. The SG only displays ICE horsepower.

The ICE is rated at 133 HP.
ICE + Battery is rated at 155 HP since the two do not peak at the same time.

Battery power is mainly used when towing for acceleration and not used to maintain speed.

When towing, it's really no different than when cruising without.
At no point did I feel "maxed out" and was loosing speed when towing.
There were times I slowed down on purpose for my personal comfort level, like others, I didn't feel comfortable running 5000 RPM for 10 minutes straight, but I certainly could have.

HTH,
-John

 

The figures 75-80 HP and running 4500+ RPMs provides needed information to those planning to or going to tow in the future. Thanks for the input.

 

gpsman1:

That's useful insight and something I can sink my teeth into. Many thanks.