2015 Lance 2185 Solar Installation

One of the best upgrades I did to our last camper was to install 200 watts of solar power in 2016.  That upgrade let us camp for weeks off-the-grid out west, where dispersed camping and most of the campgrounds don’t have electricity.  So when we bought a newer trailer this spring, I already knew what my first big upgrade was going to be.

On the old camper, I used a pair of 100W flexible solar panels and mounted them to the roof using Eternabond tape.  That worked OK, though solar panels lose efficiency as they get hot so when we should have achieved the most benefit at high noon in August in Moab, UT they weren’t actually any more effective than at 3pm in Illinois in May.  Also the protective laminate coating on the panels began to cloud up a bit and peel after the first year, degrading their effectiveness.

When I purchased the solar equipment for the Surveyor I never expected to have the camper for more than 5 years, but I intend to keep the Lance for at least a decade until all three kids are out of the house.  On top of it the 200W flexible panels were sufficient to go about 3 days in a cloudy environment before needing a full day of sun to recharge, but I wanted to be able to run indefinitely on our setup.  So with the new camper, I also wanted to install higher quality, higher efficiency, and more powerful components.

Equipment and Installation

To start, I ordered a pair of Newpowa 175W solar panels, and a Renogy Commander 40A MPPT charge controller, with remote monitor.  The Newpowa panels are monocrystaline and therefore slightly higher output (19.06V) than the comparable 160W polycrystaline Renogy panels, but are the same size.  That was important to me as it should allow me to use a different panel in the future if one becomes damaged or the Newpowa panels turn out to be garbage without moving the mounting brackets.  Monocrystaline panels are slightly higher voltage and therefore slightly more efficient in cloudy and low light conditions, which is a bonus, and the MPPT controller should be more efficient and provide better battery maintenance than the cheap PWM controller I used in the last camper.

Similar to the last camper, I wired the panels in parallel using 8AWG wire and ran everything through the roof to the charge controller mounted in the front of the pass-through, and then underneath the camper along the frame to the battery.  All the wiring was wrapped in plastic wire loom, and all entry points into the roof or floor were sealed with Dicor.

My simplified wiring diagram

Before getting started I contacted Lance customer service and they kindly provided a number of PDFs for my model year 2185 camper that I used to determine where roof studs, 12V, and 120V wiring were located.  If you have a 2015 Lance 2185 trailer you can download them from Lance Roof/Ceiling Schematic, or if you have another year or model just call Lance and they can provide ones specific to your roof.

I mounted the panels to the roof far enough forward to ensure that shadows from the A/C unit or other roof-mounted accessories were minimized, but I wanted to leave enough space that I could step to the front or outside of the panels if necessary.

Two 26″x59″ 175W panels mounted to the roof

Lance suggested using rubber well nuts to mount the panel feet to the roof instead of basic lag bolts.

3/8″ 10-32 thread well nut

While cleaning out the holes for the well nuts was time consuming and hard on my fingers, in the end I think it makes sense – the rubber well nuts should seal the hole even without Dicor and the Luan roof is only 1/4″ thick so a lag bolt wouldn’t have sufficient holding strength.

Cleaning out the excess TPO roof material from the hole was a pain

Although I didn’t take photos of it, after inserting the well nuts I ran a thick bead of Dicor non-sag sealant around the holes before installing the feet.  Then once all the feet were properly attached to the roof I covered the bolt heads and feet edges with Dicor self-leveling lap sealant.  The only place that didn’t get a second application of Dicor was the inside edge of the feed underneath the panel.

Copious coating of Dicor underneath and on top of the mounting feet

While I would really like to apply some, the panels only stand about 1″ above the roof, which is barely enough for me to squeeze a finger behind them and nowhere near tall enough to manage a caulk gun.

All the wiring was taped down with Eternabond.  If you’ve never used that stuff, it’s amazingly strong and truly can’t be pulled up once cured without significant effort.  I may cover the wiring completely in the future just to protect it from UV exposure.

Cable routed through a cable gland into the wardrobe

To route the wiring from the roof into the trailer many people run their wiring down through their fridge vent.  While I considered this option, it presents two issues.  First is that getting to the wiring involves removing the fridge, which is heavy and really a non-trivial job.  Second and more important to me is that voltage decreases over distance, and using the fridge vent would add about 15′ of wire between the panels and the charge controller, rendering the panels less efficient and ultimately producing about 5W less power. (For those interested in the math, the 175W panels generate 9.18A @ 19.06V.  15′ of 8AWG wire reduces that to 18.89V.  Assuming maximum amperage doesn’t change 9.18A @ 18.89V is about 173W).  So instead of using the fridge vent, I opted to run the wiring straight down through an interior cabinet and into the pass-through.

Wiring enters through the roof

Wiring ran down the inside of the wardrobe inside wire loom

Wire into the pass-thru is wrapped









From here the connection goes to the charge controller, which steps down the voltage to avoid destroying the battery.  To protect the charge controller, the wiring from the panels goes through a 40A Blue Sea circuit breaker.  As an added bonus, since solar panels can generate significant current when the sun is out, if I need to do maintenance to the charge controller or battery I can simply trip the breaker to disconnect the panels from the electrical system.

Charge controller, wiring, and breakers all set up

For similar reasons I put a 40A breaker on the opposite side of the charge controller as well, inline between the controller and the battery.  In theory I could have used 50A breakers for this since breakers are normally spec’ed for 120-125% of peak load, but the charge controller is only rated at 40A and I didn’t want to risk damage in the event of an over-current short of the panel, plus the controller should never see more than 18.5A from these panels anyway.

To get the wiring to the battery I drilled a hole in the trailer floor, wrapped the wire in wire loom, and ran it underneath the trailer along the frame directly to a 100Ah AGM battery.  Side note: I used marine-grade tinned copper lugs for all bolted/threaded battery connections (10-32 for the breakers, 5/16″ for the battery itself), a good crimper, and heat shrink to keep the connections stiff.  Annoyingly the Renogy controller didn’t come with a battery temperature monitor, so I ordered that separately on Amazon and will install it once it arrives.

Remote monitor, temporarily connected

Finally I hooked up the remote monitor and flipped the breakers on.  The only configuration I had to do for my setup was to change the battery size to 100A.  I was hoping to run the monitor to the interior but it only came with 6′ of RS-483 cable.  I’ve ordered 15′ of straight through Cat-5, which should be sufficient for a short run (RS-483 is similar to Cat-5 but all pins are paired (i.e. 1/2, 3/4, 5/6, 7/8 rather than Cat5’s 1/2, 3/6, 4/5, 7/8) and the cable is shielded) and will move the monitor in the future.  As you can see, the panels were generating 1A @ 17.2V while the sun was low in the sky and a bit overcast at about 7pm.


I’ll provide updates about the effectiveness of this setup once I’ve run it for a bit, but so far I’m pretty happy with the result.  About the only thing I would do differently in the future is to use L brackets to mount the solar panels instead of the solar panel-specific Z brackets I purchased.  The aluminum Z-brackets work fine, but because they mount the panel so low to the roof if I ever need to remove the panels I will need to remove the feet from the roof.  Simple L brackets mounted into the side of the panel frame rather than the bottom would be easier to remove in the future.  For those interested in replicating this setup, I’ve published my PartsList along with costs and links.

The Future

Of course owning a trailer is like owning a boat – there’s always more work to be done.

Currently lithium batteries are too expensive to use, but as the price for LiFePO4 batteries comes down I will eventually switch.  My 100Ah AGM battery cost $180, weighs 66 lbs, and can only be discharged to about 60% before it starts to damage the plate.  Two AGM batteries would give me 120Ah usable capacity and would cost $360 but weight 132 lbs.  A single 130Ah lithium battery would provide 117Ah and weight less than 30 lbs, but currently costs about $1,000.

The remote monitor for the charge controller tells me how much power is being delivered to the battery bank, but not how much I consume.  Eventually I will wire in a shunt and a full battery monitor.  I really like the SIMARINE Pico Blue but given the cost will probably start with a $30-40 basic LCD model.

The majority of the trailer runs off 12V power (lights, water pump, stereo, TV, fridge, and heater), but no way to readily power 120V appliances.  We really don’t use the microwave and I can live without an air conditioner, but it would be nice to make a pot of coffee in 5 minutes with the Mr Coffee instead of 40 minutes with a percolator, and I know Christi would like to be able to dry her hair once in a while when we’re on a long trip or recharge her laptop if she wants to spend some time writing.  I’m considering a 2000W pure sine wave inverter as part of next year’s upgrade.

If I ever need more power, there’s still enough space on the roof to add a pair of 50W-100W panels in series to the existing setup.  Shadows from the A/C might render it less effective in the morning and evening though.

New(er) camper, 2015 Lance 2185

This spring we decided to sell our 2005 Forest River Surveyor 235RS camper and upgrade to a 2015 Lance 2185.  The Surveyor served us well since purchasing it in 2012, but the boys are growing up and sharing a bed had meant more and more scuffling over space, blankets, and one of them kicking the other.  On top of that the floor space was tight, and with the Land Cruiser we now have plenty of towing capacity.

Our old Surveyor 235RS trailer.

After looking around I discovered that I could count the trailer models with triple bunk options manufactured this decade on two hands.  I seriously considered the Dutchman Aerolite 2423BH/242BHSL, which had a really cool storage and lift system for the bunks.  However the carrying capacity was quite low – so low that we wouldn’t be able to carry water, bikes, and all our remaining gear together – and Dutchman confirmed the rating was limited by the axles and not just the tires.  Also it was a full 4′ longer than our current trailer, which meant I might have to give up our nearby alley parking space.

After far too much analysis on size, capacity, quality, and price, we ended up deciding on the Lance 2185.  In terms of the layout it had everything we wanted – triple bunks, a slide out dinette, a walk around queen bed, and a (convertible) sofa.  At about 4500# empty and 6000# gross weight it was a fairly light weight trailer, and best of all it was only 16″ longer than the Surveyor.  I searched RVT.com and RVTrader.com, spoke to the local Lance dealer, and then started looking nationally for a good price with the intention of picking it up or shipping it back to us.  In the end we ended up purchasing a 2015 Lance 2185 from Camping World in Wauconda, IL, as it was almost half the cost of a similarly equipped and delivered 2018.

…with slide out

Our new trailer


Summer Road Trip, part deux

Last year it was Yellowstone. This year our summer road trip culminated in an awesome visit to the Grand Canyon.

A bit of a late start, as I was dealing with some issues from adding larger tires and a 2″ lift to the truck, but in the end it only cost us half a day.  After crashing overnight at an RV park near Keystone, NE, we started off in Breckenridge, CO Friday afternoon and met up with the “200LCDC“, a 200-series Toyota Land Cruiser club, for a multi-day trail run. Friday night we did a night trail ride up Peak 10, and Saturday we joined a subset of the group on a run up Red Cone (considered difficult) and down to Montezuma (easy).

The view from the top of Red Cone was awesome

and only a little bit of damage from a pretty tall rock we had to roll down on the trail up the mountain

Afterwards we headed to Grand Mesa, CO for a few days of hiking in the mountains before going west to Moab, UT.

Around Moab we hit two of the Canyonlands National Park districts (the Needles and Island in the Sky) as well as Arches National Park. The Needles district was my favorite. We did a short hike (about 2.5 miles) and then a longer (14-mile roundtrip) 4 wheel drive trail out to the Colorado River.

We did a few hikes in Arches though only a small portion of the 7 mile Devil’s Garden Loop

In the Island in the Sky district we took the 4WD Potash Road/Shafer trail into the park (a much more dramatic entrance than the paved highway) and stopped along the Colorado River. Once in the park we hiked out to the Grand Overlook which is where the Colorado and Green rivers meet and split Canyonlands into its four distinct districts.

After that we camped literally steps from the east rim of the Grand Canyon in the Kaibab National Park and hiked parts of the north rim of the canyon before going back to Utah.

Back in Utah we spent a day and a half in the overcrowded (but astonishingly beautiful) Zion National Park.

After Zion, we headed to nearby Bryce Canyon before driving through Escalante/Grand Staircase and a bit of Capital Reef before heading back home.

Fun stats from the vehicle computer (note with the larger tires my speedometer is 3-5% lower so all of these are actually slightly low):

  • 4463 miles
  • 36.2 mph average
  • 8.8 mpg
  • 507 gallons of fuel @ about $2.79/gallon = ~$1,414
  • 123 hours in the car
  • Potential to listen to “Holiday Road” on repeat 3354 times

Now I’ve started thinking where we want to go next year…

We’ve Seen The (Sun)Light

We’ve done a lot of camping in our trailer over the last few years, and recently decided we wanted the ability to dry camp in places that didn’t have electricity or water.  Although I upgraded the interior lights in the trailer to LED’s last year and downgraded our electric jack to a simpler hand-crank model, I still had concerns that our basic deep cycle battery from Walmart wouldn’t run the water pump and propane-powered fridge more than a couple days.  In addition, even if we could run everything for a weekend, without access to 110V power at our parking spot back home, how would we recharge the battery for the next trip?  After reading a number of blogs from full-time RVers, solar recharging seemed like the answer.

Like every new project, I ended up spending far too much time researching my options and planning the solution.  In our case, due to a combination of expected electrical draw and available roof space on our trailer, I decided on a 200 Watt setup using low profile, flexible solar panels.  The entire installation cost about $600 and took me about 8 hours, though admittedly the first 2 were spent measuring the roof over and over before I drilled the single hole in it to run the power from the roof to the interior.



First I laid out the panels on the roof in an effort to find a location where roof vents or accessories wouldn’t cast any shadows (since even a small shadow can significantly reduce the amount of power produced).  Because I needed the connectors for both panels to use the same run down the interior and to the charging controller, to get the wires close enough I ended up mounting one panel at a 45 degree angle across the roof.


After measuring probably 50 times, I drilled two 1/4″ holes in the roof and ran the 8AWG wire through the cable feed and down the interior wall between the bunk beds and the bathroom.  Unfortunately for me there was a 2×2 horizontally inside the wall, so I ended up removing the trim and wall in order to get the wire out (which sounds scarier than it actually was).  I ran the wire under the top bunk along the wall, and then down into the front pass-through storage area, covering the run with the plastic split wire loom wherever it was exposed.

I ran about 15′ of wire from the solar panels to a 40A breaker in the storage area.  This protects the charge controller from overload, and as an added bonus allows me to disconnect power from the panels to the controller or rest of the system instantly.  Since the panels deliver voltage whenever the sun is full, this will allow me to work on the system in the future without getting shocked or climbing on the roof to cover the panels.  From the charge controller I drilled a hole in the floor and ran the remaining 10′ of wire from the controller to the battery, covering it in wire loom and securing it to the frame of the trailer wherever possible.  Once secured I filled the hole from the bottom with a healthy dose of Dicor and then covered any exposed runs of wire in the storage area with wire loom as well.  I crimped 5/16″ lugs onto all ends except the roof, and made two <6″ runs to connect the circuit breakers to the charge controller.

Finally, I climbed up on top of the trailer to mount and connect the panels.  With the panels laid out I verified that the wire length with Y connectors was sufficient, but because it was sunny I didn’t connect the panels yet.  Instead I cut the ends off the single connector side of the Y connector, then stripped and butt-spliced the 8AWG wire to the Y connector and then connected the ends of the Y to the panels.  I applied 3M VHB (very high bond) tape to the back of the panels and the cable feed-through and stuck them to the roof, then cut lengths of Eternabond and fully secured the panels and all wires to the roof and used Dicor to seal the cable feed-though.


Now assembled, I flipped the circuit breakers to “On” and within 1-2 seconds the charge controller detected the battery voltage and began charging.  I adjusted the default charge cut-off (bulk stage) from 13.8V, which is far too low, to 14.8V (according to Renogy, I should charge my flooded deep cycle battery at 14.6V (bulk) and 13.8V (float)).  At 14.8V, the charge controller will run the bulk phase to the battery at 14.8V and then the float phase at 93% of that (13.76V).  With an 8AWG wire that’s 10′ in length the actual voltage delivered to the battery is 14.66V and 13.62V, respectively.  I’ll have to monitor my battery levels to make sure I don’t cook the water off the cells, but at least the math works.


Lessons Learned

Now that I’ve had a little time to reflect on my installation I realize there are a few things I would do differently in the future, or might change about my current setup:

  1. The circuit breaker for the battery should really be as close to the battery as possible, so that if the wire ever shorts the circuit breaker will trip before the break, not after it.  I may move this in the future since the circuit breakers are supposedly waterproof.
  2. While I was able to get a decent crimp, I should have opted for a more expensive crimper and lugs (and possibly 6AWG wire).  Even though the lugs are crimped tight to the wire and the wire is stranded, I suspect I’m getting some loss at each one.
  3. To fully charge a battery, you need to apply a bulk charge of 14.4 to 14.8V for several hours, then reduce the voltage to 13.5-13.8V and maintain the float charge at that level.  The precise voltage depends in part on the battery type.  In hindsight I should have purchased a better MPPT charge controller which allows separate adjustment to the bulk and float stages, has an automatic equalize (overcharge) mode to desulfate the battery plates, and because it’s MPPT has a higher efficiency (which is best for northern climates that don’t get tons of full sun hours).  My WindyNation P30L controller has a single “Over Voltage” setting point at which it shuts off (13.8V by default).  According to WindyNation, this is the “bulk charge” limit and the “float charge” is fixed at 93% of this value.  Thus to get a 13.5V float I have to set the bulk charge at 14.6V.
  4. I was originally concerned with significant voltage drops in smaller gauge wire, so I bought 8AWG, which allows me to run 20A @ 16′ with no more than 3% voltage loss.  However with only two 100W panels I’m not going to exceed 12A.  In reality 10AWG wire would have been cheaper and I believe there are even pre-wired MC4 cable lengths available up to 10AWG.

So far I’m very happy with my setup.  And while it’s not sufficient for a full-time RVer who wants to run their A/C in the summer or watch TV in the winter, it gives us so many additional camping options, even allowing us to use more secluded non-electric sites at state parks.

Towing with a 200-series Toyota Land Cruiser

I’ve read a number of different thoughts and opinions about towing with the 200-series Toyota Land Cruiser.  One popular opinion which seems to come mostly from owners of full size diesel pickups, is that due to the relatively short 112″ wheelbase, the Land Cruiser is a poor towing vehicle.  After a few trips and tweaks to my setup, I can confidently say that with the proper setup, the Land Cruiser is actually a great towing vehicle.

Keep in mind everyone’s trailer and towing setup will be a bit different, so rather than take my setup as the bible I recommend you try out your setup and make small adjustments until you’re happy with it.


The Vehicles

My basic setup is a US-spec 2013 Toyota Land Cruiser with the 3UR-FE 5.7L V-8 engine, rated to tow 8,500 lbs with an 850 lb maximum tongue weight, and a 2005 Forest River Surveyor 235RS trailer which weighs about 5,000 lbs and has a roughly 600 lb tongue weight when loaded with all of our gear (except fresh water).  Prior to the Land Cruiser we towed with a 2008 Acura MDX with 5,000 lb rated tow capacity, which definitely pushed the limits of that vehicle.  Aside from the trailer, when camping we have 2 adults, 3 kids, a 75lb dog, a cooler full of food and ice, as well as clothing and other miscellaneous items in the vehicle (easily 650-700lbs).


Weight Distribution

One of the keys to the proper towing setup is a good weight distributing hitch with anti-sway setup.  When I purchased the trailer I brought it home using a basic hitch and standard 2 5/16″ hitch ball.  When I got home I immediately ordered a Pro Series Weight Distribution Hitch with Sway Control for about $250 from eTrailer.com. (Note: Because I never expected my tongue weight to exceed 500 lbs I purchased the basic PS49901 model, with a 550lb limit.  While I’ve considered upgrading the bars to allow me to shift more weight and better level the vehicle, the heavier bars tend to make the ride stiff and bouncy).  When engaged, the weight distribution (WD) hitch and trunnion bars transfer a portion of the tongue weight off the rear axle onto the front axle of the vehicle.  I once weighed the Acura at a truck stop with and without WD and the setup did shift about 80-100 lbs to the front axle depending on how many links on the chain were pulled up.


When I moved the Pro Series WD setup to the Land Cruiser, I discovered that the trailer was not level (nose-up by several inches).  While most trailer hitches are level at 21-24″, the Surveyor frame sits about 6″ lower to the ground.  Thus even at the lowest setting, the hitch ball was at least 4″ too high.  When combined with less tongue weight (one empty 30# propane cylinder and no bicycles stored in front), the trailer felt squirrel-y on the highway whenever there was a gust of wind.  To get the trailer level when towing, I ended up purchasing a taller weight distribution hitch bar (shank) from Amazon for $75, which allowed me to drop the height of the hitch ball several inches lower.  For my setup, I purchased a Curt 17123 (which is actually 12.25″ tall) with the WD hitch mounted at the lowest setting makes the trailer almost perfectly level after my last modification.

Helper Air Bags

While the WD hitch does a solid job, I carry varying loads at times depending on whether we bring all 5 bicycles, how much propane is in the tanks, etc.  I considered using a heavier duty WD setup, but the stiffer bars have a lower limit of 550 lbs which could present handling issues when running a lower tongue weight.  In addition, it’s recommended that 8 to 15% of your trailer weight be located on the tongue, and with a 5,000 lb trailer I was concerned about shifting too much weight off the tongue and onto the front axle as trailer sway, especially as caused by tractor trailers at highway speed, can be a serious problem.  Rather than change to stiffer WD bars, I realized I needed to do something to better support or strengthen the rear suspension.  That left me with two options:

  1. Upgrade the rear springs from standard to heavy duty (340lbf/in) or more.  While this would limit compression (and thus the rear end sag) when towing, the stiffer springs would almost certainly make the rear end quite bouncy when unloaded.  As the majority of our non-towing driving is on city streets loaded with potholes, I was afraid any upgrade would completely ruin the ride of the vehicle.
  2. Install a set of helper air bags inside the springs and inflate them when towing.  This has the benefit of allowing adjusting the stiffness depending on the situation by adding or removing air from the bags.

I ended up opting for the helper air bags and purchased a Firestone 4164 air bag kit and a standard duty Air Lift 25804 air compressor from Amazon for under $250 and documented the installation here.  I’ll summarize that article with the following quote:

With 35psi in the bags, the Land Cruiser towed like a friggin’ champ.  The ride was very smooth, and with the anti-sway bar installed I had no trouble running 70+mph on the highway.  All in all I’m very pleased with the setup.

Sway Control

The Pro Series Weight Distribution Hitch I ordered comes with a friction anti-sway device (available separately for $40).  It basically sandwiches a piece of metal between two other pieces which you compress by tightening a bolt on the device.  If you’re towing anything more than a pop-up at 45mph or higher, you really want one of these.  The device takes less than 60 seconds to install or remove, but does a great job of limiting swaying in crosswinds or when passing tractor trailers on the highway.


The Land Cruiser comes with a trailer brake controller port, but if you’re towing a trailer with a GVWR > 3,000lbs, you’ll need to order and install a controller and wiring adapter.  I purchased a Tekonsha Primus IQ a few years back for  the Acura, so I just needed to order the Tekonsha Toyota Wiring Harness.  Installation took about 30 minutes by following the Trailer Brake Controller Connector discussion over at iH8mud.  I mounted mine at the bottom of the dash on the left side – out of the way, but requires me to lean forward to adjust it.  My biggest complaint with the Primus IQ is that I feel like I’m always fiddling with it to get the braking proportion just right, which sometimes leaves me locking up the rear tires at low speeds.


The last upgrade I made (and highly recommend) was to purchase an ELM327-compatible Wi-Fi OBDII reader ($15-20) and the EngineLink App for iOS ($6).  When towing I insert the reader into the OBDII port and connect my iPhone to the CLKDevices WiFi name, then fire up EngineLink.  Based on a number of other threads I read, I added two additional gauges in order to be able to monitor the automatic transmission pan and torque converter temperatures while towing:

  • Toyota A/T Pan Temp. PID 2182. Formula ((((A*256+B)*(7/100)-400)/10). Range -40 to 300. Units are F.
  • Toyota A/T TC Temp. PID 2182. Formula ((((C*256+D)*(7/100)-400)/10). Range -40 to 300. Units are F.





Because the Land Cruiser is over-built, there’s no need to add a separate auxiliary transmission cooler.  However, when towing you should always put the vehicle into “Sport” mode by pushing the shift lever to the left.  The “Sport” (or manual shift) mode limits the vehicle to no higher than 4th gear unless you manually select 5 or 6.  This is Toyota’s recommendation as well.

Based on my own monitoring of transmission temperatures, 4th gear (which is 1.000:1) minimized torque converter spin and significantly reduces heat.  I wrote about my experience in this posting at iH8mud:

Limiting the vehicle to 4th gear I was cruising at 65-70 in mostly flat Illinois/Wisconsin (I-94) and ran around 2800RPMs +/-. I got ~10.5MPG at that speed (the instantaneous MPG reading from OBD2 was pretty steady between 10.2 and 10.8MPG). I tried running in 5th for a while but I found I had to lay into the gas pedal more to keep it at 65, so my gas mileage actually went down. Unless I was driving 55, using OD provided no MPG benefit.

I also watched the temps closely during the trip. Outside it was ~65F out. Intake temp was reading about ~90F (typical). My trailer was at the shop getting the bearings repacked so I drove about an hour to pick it up and then about an hour after I hitched up, thus I got some great comparison #’s:

  • Without a trailer running in top gear (6th) the transmission pan temp reached 195F (+/- 1F degree), and the torque converter was anywhere from 195F (when fully locked) to about 208F (for instance when accelerating from 60-70). The higher TC temp didn’t affect the pan temp much. Once the TC locked up again at ~70MPH the temps would both stablilze around 195F again.
  • With the trailer running in 4th gear the pan temp stayed around 196F (+/-1F). Both the TC and the pan temp would read the same when cruising at 65MPH. About 2/3 of the way through the trip I tried running in 5th gear (first OD). The TC temp would climb (at one point it hit 213F) and the pan slowly climbed up to about 202F over the span of about 5 minutes before I put it back in 4th. At that point the temps slowly dropped down to 195F again. Also, I definitely noticed the weight of the trailer a LOT more when towing in 5th than in 4th.

In short, don’t tow in overdrive – the gas mileage difference is small and OD generates heat in the transmission, especially if the ambient temps are warmer and/or you’re pulling through hilly terrain. Yes if you’re pulling a 2000# 4x5x8 uhaul trailer you can probably run in 5th or 6th without any damage, but if you’re pulling a smaller trailer running in your 1:1 gear (6th in your case) will have less impact on your MPG than it does for me, so the $ savings is minimal.

I had a second opportunity to confirm my temps this weekend when the outside ambient temperature was 86F and got nearly identical results.  At 70mph on the highway the engine temp read 194F and both the pan and torque converter on the automatic transmission read 198.5F.

I understand the “A/T Temp” warning light will come on at 302F, though I hope to never confirm that.

Last Thoughts

With the proper setup (weight distribution, anti-sway, and upgraded rear springs or helper air bags), the 200-series Land Cruiser has no trouble towing a 24′ travel trailer weighing 5,000 lbs.  We don’t intend to upgrade our trailer, but if we did I wouldn’t hesitate to go up to ~26′ and 6,000 lbs.  While you should always follow manufacturer recommendations, I felt very comfortable cruising at 70mph and am looking forward to taking a much longer trip to Mt. Rushmore later this summer.  As I said in the air bag installation posting, the Land Cruiser towed like a friggin’ champ.