Towing performance - gearing, headers, or.. ? (1 Viewer)

[Flagstaff100]

I've gone through all the towing threads and didn't find any discussion on this.

We just bought a 2018 Rockwood Roo 183 (#3900) hybrid trailer. I drove out to TX from AZ in my 07' LX470 with 140k on the clock (and 275/70/18 AT) to pick it up. We travelled about 1300mi (3,200 ft elevation to 7,000 ft). The first leg of the trip was a learning experience, I was trying to maintain ~65 mph with cruise control, and ended up getting 6.7 mpg. West TX is windy as f&^$ too, which I'm sure contributed to the poor performance. The next leg I chilled out and kept the speeds between 50 - 60, which felt a lot better on the RPMs and we started getting 9 - 10.5 mpg - albeit having semi trucks passing us constantly. Truck stayed in 3/4 gear the whole time. I'd love to have a little more power to make the experience more comfortable (would love to be able to maintain 65). Disclaimer: I knew when I bought the LX that it wasn't as good a tow vehicle as a 3/4t or diesel but wanted something that was capable for the forest and trail stuff we also do.

A couple notes:
- I live at 7k feet elevation, with some steep hills I go up and down when traveling (7% grades)
- I have a WDH and Brake Controller.. the truck felt fine in terms of stability while towing
- 33 inch (Cooper AT3 XLT)
- There was about half a tank of water in the trailer during this drive. I left it in there to simulate the extra weight we'd travel with. When we do travel with it I'll be dumping all fluids before moving campsites.

We're mostly planning on taking trips here and there, but we are doing a 7 week trip this summer with our 3 small kids. So if the truck is what it is, it'll be fine. We can just put reggae music on and do 55 mph. But I do have some funds that I can use to make it better if there is an option available to do so. I've been looking at ways that I might be able to improve the performance and came up with a couple options.

- Swapping out the gearing (considering the 33 in ATs and towing occasionally - not too concerned about the reduction to non-towing highway speeds as I don't do that too often)
- DT headers. Thought I'm not sure if the performance increase would translate to any better towing performance here.

Any other thoughts or suggestions?

 

[MongooseGA]

I can't speak to towing (yet), but I can speak to the power addition with the DT headers.

On an otherwise stock, healthy vehicle, I noticed no discernible performance difference with the headers alone. I've read you need to pair them with a complete exhaust system and there's a dyno proven improvement (40ish at the wheels I think?) But for me, it wasn't worth the $1200 +/- installed for them. You'd be better off just applying those funds to gas, IMO.

 

[kelly saad]

It’s the trailer height and the air hitting the front slowing you down. I have a tent trailer that weighs about 3000 lbs and a bass boat 3600 lbs they both pull everywhere like a dream. Also, I have a 98, non VVT motor, less power than yours. When I rent a box trailer from uhaul and pull Mitch my old tundra, I notice it on the highway, it’s really bad. My mileage goes to crap and I feel like I’m driving into a strong headwind, uphill.

 

[Somebodyelse5]

Unfortunately, the 100 series is not a good tow pig. It's stable and heavy, but it doesn't have the torque (we all wish that it did). Gearing will help but none of the other mods will get you much improvement. You'll be better off just accepting the slower speeds and remembering you are dragging a sail

 

[Flagstaff100]

It’s the trailer height and the air hitting the front slowing you down. I have a tent trailer that weighs about 3000 lbs and a bass boat 3600 lbs they both pull everywhere like a dream. Also, I have a 98, non VVT motor, less power than yours. When I rent a box trailer from uhaul and pull Mitch my old tundra, I notice it on the highway, it’s really bad. My mileage goes to crap and I feel like I’m driving into a strong headwind, uphill.

I figured that was a main source of it. We pulled a 2200# popup with the Sienna and it pulled better than the LX and this trailer.

btw, I've seen people mention you before, I had no idea you're here in Flagtown. We should meet up some time.

 

[kelly saad]

I figured that was a main source of it. We pulled a 2200# popup with the Sienna and it pulled better than the LX and this trailer.

btw, I've seen people mention you before, I had no idea you're here in Flagtown. We should meet up some time.

Yea, lets meet up. I have been here 10 years. Live off Country Club.

 

[GTV]

4.56's would put your overall gearing back to factory and would make a bigger difference than performance mods, unless your headers (and/or rest of the exhaust) are leaking and need replaced anyway.

Also, I'm not sure if you already know but it isn't good for the transmission to tow with overdrive on. Going down hills with it on is ok, other than that leave it off. With overdrive off I don't like to go faster than 65mph anyway (in my 00 Tundra), it just revs too high and drinks too much fuel.

 

[hoser]

The next leg I chilled out and kept the speeds between 50 - 60, which felt a lot better on the RPMs and we started getting 9 - 10.5 mpg - albeit having semi trucks passing us constantly. Truck stayed in 3/4 gear the whole time.

IMO, that's the key to it right there. 50-60mph, 3rd & 4th gear. Wind resistance is the killer. I would also install a transmission fluid temp gauge like a scangauge.

 

[TXLX100]

I ran into same issue with my v8 4runner. 3500 lb 20' trailer towed awful (compared to a half ton pickup with v8 and less horsepower). Going 55-60mph and whiteKnuckle with it was zero fun. If I had kept the trailer, would have put smaller tires and re-geared.

 

[Flagstaff100]

I'd be interested in the gear swap. I searched for 4.56 gears and can't really find anything for the 100s. Lots of 4.88 kits but it seems that all the 4.56s I can find are listed for FJ80s. I think that's beyond my skills at this point, might need to call a local mechanic to check feasibility. @kelly saad who do you use locally? A friend with a GX swears by R&A.

 

[BudgetLC]

I know this is blasphemy but the cheapest performance gain might be going back to stock sized tires (6% difference). Down side is you lose some of your off-road clearance. Ditch the runner boards and it would probably be a wash.

That being said, your probably still not going to be thrilled with the performance while towing no matter what you do. My brother bought a similar sized Lance 1685 trailer a couple of years ago and towed it with his V-8 4Runner (approximately 1000 lb's lighter than a LX470). After a year or so, he sold the 4Runner and bought a new 5.7L Tundra. He decided that the towing ability was more important the the off-road capability since he uses his mountain bike for most of those adventures (FWIW, he's 61).

So, if you are going to keep your LX470, learn to slow down and accept that you are still going to get bad gas mileage while towing or start saving for a newer, more powerful vehicle.

 

[Flagstaff100]

@BudgetLC haha totally. I'm okay with going slower. My worry after the first leg of the tow on Sat was that my range is totally shot (@ 6.7 mpg). I was already looking at listings for 200 series and cursing myself for not researching this more. If I was getting 130mi before stressing about finding a gas station I'd be pretty bummed. Once I found out that 9 - 10 mpg was doable then I was okay with it. I already told my wife that we'll need a Bob Marley playlist. I'd love to have just a bit better pull, but if that's not possible I'm good with it. I'm sure living at 7k ft elevation is a factor as well. We honestly don't tow that often, and towing was never my number 1 reason for getting a 100. This year we'll be doing a longer trip (at sea level), but most times it'll just be a weekend here or there.

 

[kelly saad]

I'd be interested in the gear swap. I searched for 4.56 gears and can't really find anything for the 100s. Lots of 4.88 kits but it seems that all the 4.56s I can find are listed for FJ80s. I think that's beyond my skills at this point, might need to call a local mechanic to check feasibility. @kelly saad who do you use locally? A friend with a GX swears by R&A.

I use Findlay Toyota, but I know all the guys over there. Doing gears though I would find an expert that does that often. I don’t think it’s going to help though, my 2017 Tundra with 380 HP did exactly the same thing pulling a 12’ box trailer to Kansas, with only a motorcycle inside. I think it was 8 mpg part of the way.

 

[EZDog]

Its funny but I have pulled my trailers all over the place with 2001 Tundras,one with the V6 & then with the V8 and while the MOG is never anything to be proud of the Tundys do pretty well for power and keeping speed,even the V6!
I also always have the trucks loaded like crazy but they are probably still a lot lighter than the Cruiser is even empty.

My 17' Casita is a little more Aero than those boxes I guess and it does pull the best over the boxier rigs that I pull for sure.
Sometimes what seem like small differences can make a huge difference in towing feel.

 

[Somebodyelse5]

I know this is blasphemy but the cheapest performance gain might be going back to stock sized tires (6% difference). Down side is you lose some of your off-road clearance. Ditch the runner boards and it would probably be a wash.

That being said, your probably still not going to be thrilled with the performance while towing no matter what you do. My brother bought a similar sized Lance 1685 trailer a couple of years ago and towed it with his V-8 4Runner (approximately 1000 lb's lighter than a LX470). After a year or so, he sold the 4Runner and bought a new 5.7L Tundra. He decided that the towing ability was more important the the off-road capability since he uses his mountain bike for most of those adventures (FWIW, he's 61).

So, if you are going to keep your LX470, learn to slow down and accept that you are still going to get bad gas mileage while towing or start saving for a newer, more powerful vehicle.

There is a reason the best tow pigs are diesels. If milage and speed while towing are what's important... a 3/4 or 1 ton diesel is really the only solution. Everything else is a compromise.

 

[ga12r1]

@BudgetLC haha totally. I'm okay with going slower. My worry after the first leg of the tow on Sat was that my range is totally shot (@ 6.7 mpg). I was already looking at listings for 200 series and cursing myself for not researching this more. If I was getting 130mi before stressing about finding a gas station I'd be pretty bummed. Once I found out that 9 - 10 mpg was doable then I was okay with it. I already told my wife that we'll need a Bob Marley playlist. I'd love to have just a bit better pull, but if that's not possible I'm good with it. I'm sure living at 7k ft elevation is a factor as well. We honestly don't tow that often, and towing was never my number 1 reason for getting a 100. This year we'll be doing a longer trip (at sea level), but most times it'll just be a weekend here or there.

I tow a Jayco Jayfeather 17xfd that’s really close to what you have. I’m running 35ish tires with 4.88s on a 2000 LX. Towing from South Ga to Silverton Colorado and back I averaged 7.8 MPG. That was running 65mph the entire trip at 3200 RPM. It was slow but definitely doable. I just had to sit back and relax. This year I’ve added DT headers and DT catback exhaust. We will see if there are any improvements on this years trip.

And as far as a 200 goes it definitely pulls better and has more power, but the MPG isn’t much better. I think I was getting about 8.5 MPG towing at 65 mph. I am running 33.5 tires though. I’m sure it would be better with stock size tires.

 

[hickuptruck]

Trade for a LX570

4.88 Gears
Smaller tires, but i know, the stock 31s look dinky on the 100.

 

[1999WhitePearl]

We have a 200, a 2013 tundra with the 5.7, and 3 100s. The 200 and the tundra obviously PULL better, but don’t get much better mileage towing than the 100s. YMMV. The brakes are also much bigger and nicer on the 200 and the Tundra’s are amazing.

 

[Flagstaff100]

I tow a Jayco Jayfeather 17xfd that’s really close to what you have. I’m running 35ish tires with 4.88s on a 2000 LX. Towing from South Ga to Silverton Colorado and back I averaged 7.8 MPG. That was running 65mph the entire trip at 3200 RPM. It was slow but definitely doable. I just had to sit back and relax. This year I’ve added DT headers and DT catback exhaust. We will see if there are any improvements on this years trip.

And as far as a 200 goes it definitely pulls better and has more power, but the MPG isn’t much better. I think I was getting about 8.5 MPG towing at 65 mph. I am running 33.5 tires though. I’m sure it would be better with stock size tires.

We actually looked at that same Jayco. Nice setup! That's great to know about the 200 as well. I figure part of the mediocre experience was climbing 4k ft of elevation in moderate wind, and the elevation itself. We're headed down to Sedona for our first camping trip in a couple weeks. Probably just going to have to chill and let it do what it's going to do. Let me know how the DT setup does for you.

I use Findlay Toyota, but I know all the guys over there. Doing gears though I would find an expert that does that often. I don’t think it’s going to help though, my 2017 Tundra with 380 HP did exactly the same thing pulling a 12’ box trailer to Kansas, with only a motorcycle inside. I think it was 8 mpg part of the way.

I was thinking more from an improved RPM standpoint. At 60 I was around ~3200, every time I tried to get up to 65 I was either dropping into 3rd (4000 RPM) or getting the throttle just right and then waiting a minute or two. I honestly don't know much about drivetrain, or even what a regear would entail though. So it might not be a good option. It might be more $ than it's worth too. Don't know yet.

 

[J1000]

I also bought my 100 because it was the perfect mix of everything I wanted in an SUV. I use it to tow and towing is definitely not its strong suit. Firstly, I just mash the throttle and let it downshift to 3rd and rev out to redline. IMO engines are made to be used there's no harm in running the engine where it makes the best HP.

The next thing which is the easiest and cheapest performance upgrade that I'll probably be attacked 6 ways from Sunday for even mentioning is converting to E85. If it's readily available around you I'd seriously consider it. From my experience it costs about the same $/mile as 85 octane regular gas, but gives the same or more power as 91 octane. So you get more power but less fuel cost. I towed my car trailer which is about 4,300lbs loaded a few weeks ago a few hundred miles and got 9 MPG on E85. I am also at altitude.

edit: also definitely install some airbags. I got some Airlift 1000s and they went in super easy, less than an hour. Makes a massive difference when towing too and you can adjust the air pressure to your liking.