Towing a 4500lb TT with an SUV

I just bought a used Jeep Grand Cherokee. And tried it on a 4000 lb tt with good results.
I borrowed a friends tt and went only a couple hundred miles but the little Jeep did well.
It has a 4.7 V-8, 4wd, and the 3.73 final gear so the tow cap is listed as about 6500. I don't know that I would want to go there but for what I picked up, I've been impressed.
Non towing Mileage has been close to 16, towing it dropped to just under 12, and I do have a light foot.
There are some 5.7 engine ones out there with a little more ooomph, but this seems good to me.

Twelve to fifteen or better MPG with a 4350 trailer, even a hi-lo, isn’t realistic. At that weight a full size SUV or truck is best IMO. Are you within payload on the Pilot?

12-15mpg for towing?

Not gonna happen, just the nature of the beast.

Think of it like dragging a cement block the size of a billboard behind you.

Not even modern Diesels get that mileage when towing (pre emission Diesels often could get 15-19 MPG towing, newer emission Diesels are lucky to get 15 MPG empty.

Expect 9-11MPG for gas engine as a typical average, add in a lot of steep grades with heavy go peddle and you can be nearer to the 8-9MPG club.

Speed also will affect towing mileage, the faster you go, the worse it gets, lighten up on the go pedal, do not expect to drive it in a top fuel dragster mode and get decent mileage. You WILL drop speed and it WILL downshift going up grades and that WILL use more fuel.

To help make a comparision, one of my older trailer and truck combinations was a 97 Ford F250 with 5.4 and 20ft trailer (empty was 3,600 lbs and loaded was 5,800 lbs).. That combo gave me 9.1-9.9 MPG at 65 MPH.

My current combo, 2019 F250 6.2 gas engine, 26Ft TT (empty 5,000 loaded 6,200) gets me 9.1-10.1 MPG at 65 MPH for same route.

Just hooking up my 10K flat bead dovetail utility trailer with no load drags my mileage down to 10 MPG while towing and it only weighs 2,400 lbs empty.

Anyone that tells you they get 15 MPG with a gas engine while towing is lying and heck even the Ecoboost turbo F150 does the exact same thing, sure they can get 20-22 MPG EMPTY but hitch a trailer on and they drop down to 9-10MPG.

If you are seeking some off road type of adventure, a pickup truck with a fiberglass cap might work better for that.. You can setup a table/bed in the back, put some curtains in the windows and not have to deal with removing SUV seats although you would not have heat of A/C but some caps have windows which can be opened.. SUVs you would have to workaround seats that are not optimized for sleeping, carpeting and so on..

^This. Some motors can be efficient when solo, but all motors drink heavy when towing. Although having more torque than the Pilot will help slightly (like 1-2 MPG) because you'll be able to maintain a lower RPMs. The EcoBoost is great for occasional towing, because it's very powerful, gets good mileage when un-hooked. But it'll still use almost as much fuel when towing.

That said... If towing mileage is a requirements, the baby-diesels shine here. But they still are plagued with emissions problems when driven in town, and you give up half the horsepower compared to the top-end gasoline offerings.

Suburban or Expedition and forget about good mpg when towing, not going to happen. To understand what the forces a vehicle has to deal with hold a sheet of plywood in a 20 mph wind. Now imagine what it takes to overcome a 60 mph wind.

An honest salesman guided me away from SUV's with the comment, "People have enough trouble keeping them right side up even without towing."

As said above. Fuel mileage is more dependent on what your towing, how fast and the conditions than what your towing it with.
Don’t expect towing mileage, accept towing mileage.
Most any newer Mid or full size suv with a V8 will pull it effortlessly. Pick your favorite color, size and brand.

11.1mpg over 28k miles of towing. We usually have cruise set at 68 mph, just a wee bit faster than the big rigs that are governed to 65 so we don't play leap frog with them. I've tried going faster when in the flatter parts out west but fuel economy really suffered quickly, to the point where the extra gas stops were pretty much negating the speed increase. The worst tank we had was 8.5 going into a 45mph headwind in Florida for several hours. This is a 5.3 v8 hauling a little 3,600gvwr trailer. We do a little better than average not because the trailer is light, but because it's only 7' wide and under 10' tall.

All great advice above.
I'm towing a lighter TT at 3877# GVWR. With my previous TV, 2008 Ford Explorer tow rated 5225#, it towed great EXCEPT the engine was a dog. CAT Scaled it and turned out I was at 85% GCWR, and mildly overloaded on my drive & trailer axles.
Got a 2019 F150 and am super pleased when towing. And it's my DD. It did take some getting used to the 4 door's length and width compared to an Explorer. Even with the short bed, it is 10" longer than my old 1998 Expedition was (sold in 2016). Still only get get 10.3 mpg when towing but it's better than the Explorer's 9.8 mpg on a good day. V8 5.0L vs. V6 4.0L.
You don't mention kids. A standard cab or even a short bed extended cab pickup is easy enough to drive in town and could gain you a lot more towing power with a lot more options with the bed VS. an SUV.

I'm not a fan of towing with a small vehicle such as a mid sized SUV. I always feel like the tail is wagging the dog. I would suggest a full size SUV like a Tahoe or Yukon. We had a 2007 and it got great gas mileage on the freeway but we never towed with it. Not sure how it does towing, but a larger vehicle won't stress as much when towing like a smaller vehicle will. I also like the new 1/2 ton diesels if you are looking at a new vehicle. They get amazing gas mileage and have good towing for smaller trailers. I wouldn't suggest maxing out their towing capabilities as they don't perform well on hills with heavy loads, but should with the trailer you have. Most of us consider that the gas mileage you get with a trailer is just what you get. It the sacrifice for towing a trailer.