In thinking about it, it was almost like a stuttering condition .......

 

Took it out again today. No wind, smooth roads. Brake controller was actually a bit under powering the trailer (I warmed up the brakes a bit, then reset them to the right level).

Still had the surging/stuttering issue albeit not as bad. Even had it when coasting. I asked my wife if anything was different in the trailer and she said that when the scouts cleaned it out, some things got put back in a little different order. I looked inside and I'd say a lolt of the weight is in the back of the trailer. I also noticed I was going a bit "uphill" with the trailer (nose was up a bit).

I'm out of time today, but want to try it again with more weight on the tongue (front of trailer) and pulling it a bit downward. My neighbor who pulls his souped up mustang to the track said that if the back end is too heavy, it can cause this issue. He said the only other thing to try is a trailer sway system (he said it was overkill for that trailer).

 

I've noticed this too. Although, I can get it to happen even when not pulling the trailer. I've narrowed it down to a slight acceleration, and only when in V8 mode. Although when I have the enclosed trailer attached, it's more noticeable when cruising at highway speeds. Anytime I'm off the gas it goes away. I still haven't brought it to the dealer for it yet.

Oh, naperville, huh. I was just in Wheaton all day. I live downtown though.

I posted about this a few weeks ago as well. Read here to see if your issues are the same. https://www.greenhybrid.com/discuss/f69/surging-24223/

 

I too have noticed a slight surge/falloff under normal driving but like someone else said, I think that's normal for a EVT system when toggling in and out of EVT and gas. I see you say it's more pronounced under load (with your trailer). That is mine, too. I don't feel it when in low RPMs though. I do feel it when I'm trying to get up to 60 and am accelerating a bit harder than normal (I am towing about 4500 lbs though). Tach is about 2200 RPMs and the stuttering is very pronounced. If I coast that that point, the stuttering is reduced, but quite noticeable. Display says I'm in V8 mode and no electric motor is assisting me at that time so EVT should be out of the way.

I'll see what happens when I move some weight around and drop the nose a bit. I hope that improves the situation. If not, I have a friendly/understanding contact in the shop at the local dealership (I've known him for 17 years or so and have bought 4 cars there over the years) and see what he says. He's used to hauling his own trailer.

I've only seen 3 hybrids out here in the Naperville area - might you one of them? I've seen another black one like mine, a white one and a tan one. All with the hybrid markings on 'em (mine were gone when I bought, otherwise, I was going to have them removed). The only thing I miss is the 4-6 inches of gradient sun block most vehicles have at the top of the windshield. Makes driving into the sun a real eye burner!!

 

I'm rarely in Naperville. Mostly downtown. Black with no hybrid badges.

Just to see if we're having the same problem: Mine doesn't do it when I switch to "M". Also, the surge is very constant, like every second or so. You also said that your RMP's don't change, well mine change sometimes, maybe about 200 RPM fluctuation. I'll be towing to Michigan next weekend, so I can check it out some more then. Oh, I'm towing about 2500 lbs.

This is also much easier to notice when driving. My girlfriend thought I was nuts till she was out driving one day (without the trailer) and felt it.

I'm glad you posted this up, I was starting to think I was nuts being the only one on the forum feeling it!

 

The tongue of the trailer should always be ~200lbs +/-50 to keep things stable. If you have it too light, it will try to drive itself and can get spooky.

 

Having never pulled a load this heavy before, I am really starting to think this is the issue (tongue to light). Will see in a couple of days when I get to it again.

On a side note, does anyone know how high is too high on the trans temp? Daily driving (less than 10 miles stop and go one way) doesn't
show the temp higher than ~145, but when I pulled the trailer about the same distance on Sunday, hit 169. After unhooking and driving home, temp never really got below 160.

 

When towing, mine does it regardless of where the shifter is. I'm starting to lean towards it being to light on the tongue weight. Without the trailer at low speeds, I can feel it when the electric cuts in and out, but rarely at higher speeds (and again, is usually around the electric cutting in and out as I drive).

Have you had a chance to get it to your dealership yet?

 

General rule of thumb is ~10% tongue weight.

 

That sounds reasonable, but how does one test for that condition?