2017 Toyota 4Runner 4.0V6, towing, my experience

[Doug2000]

Ok, so I have seen a few people ask about the Toyota 4Runner as a tow vehicle for our fibreglass trailers and this is my experience. I just returned from a 8700km trip from London Ontario to Los Angeles and back and this is what I think.

First, my setup, a 2017 Toyota 4Runner TRD Off Road, all stock with factory tow package which includes pre-wire for the brake controller, hitch, and transmission cooler integrated into the rad. The trailer is a 2007 Escape 17B, dry weight, 1900lbs. I use a EAZ Lift weight distribution hitch as the rear suspension is a little soft on the bumps going down the highway. I also use a ScanGuage2 to monitor my transmission temperature.

My previous vehicle was a 2008 Tacoma, but my boys outgrew the back seat, so I needed an upgrade. With gas prices in Canada approaching $5.25 a gallon, I really didn’t want a full size, so I chose the 4RUNNER for its massive back seat.

So, gas mileage, with my Tacoma, I used to get 13 to 14 mpg towing mostly towing in 4th gear, the 4RUNNER is a big improvement, on the trip from London to LA, I got 14 to 17 mpg using the ScanGauge2 and towing in OD as much as I could. The ScanGauge2 has easily paid for itself.

When selecting a tow vehicle I was told a long time ago, try to stay under 50% of your tow capacity if your going to be running long trips, pretty good advice, towing is very hard on a vehicle. I’m sure loaded up, I am right around 50%.

Elevation Elevation Elevation, under 3000’ the 4Runner pulls the trailer in OD no problem, the torque converter doesn’t unlock unless you lean into it. Under 6000’ you are towing in 4th gear and dropping to 3rd on the hills. On our trip, I took the trailer over Loveland Pass, at 11,000’ I put it in 2nd gear and held the rpms at 3k to make it to the top. That was partly because of the switch backs, but also I wasn’t pushing very hard. My transmission temp only hit 217F. Oddly enough, we were the only RV up there. When we were heading through western Utah on I70, I pulled over after the temp got to 230F, it was a 10 minute pull up a Pass in 3rd gear. That’s the hottest it got. The Toyota dealer advised me at 240F is when you should be concerned.

One thing people don’t realize is when the torque converter unlocks, the temperature spikes, in 10 seconds, the temperature can go from 180F to 210F, that’s why I like the ScanGauge2 so much as it has taught me how to maximize my setup.

My impression is the truck can easily handle a 19’ as long as I stay east of Denver but I feel towing through the Rockies, the 4Runner is maxed out at the 17’ that I have now. If I was to do the trip again, I likely would buy a Toyota Tundra.


The 3rd pick is climbing Loveland Pass, Colorado, 2nd gear, 3500rpm.......11,000'

[Bill and Earline]

Excellent, informative write-up, Doug.
We had very similar experiences towing our 2014 21' the first two years and 20,000 miles with our 2003 4Runner V6. That year it only had a 4 speed, and the owners' manual said you would get a little more power using Premium gas, but I couldn't tell. I used the ScanGauge II, as well, and I had received the same caution about 240F.

We still own the 4Runner, and it remains a great car, but not our tow vehicle. There are quite a few owners using 4Runners, Highlanders, and similar vehicles, which they find entirely satisfactory, even towing 21s. It just requires a higher level of driver attention to temps, rpms, tongue weight, etc.

I have to say, using a full size pickup certainly is more relaxing, but many prefer the ease of step-in of a mid-size SUV, not to mention they are easier to park and to fit into garages.

[Viajante]

Thanks for the info, Doug. Something I like about the 4Runner, at least the 2008, is that there are two transmission temp sensors. You can see the temp before and after the cooler. You are right, the torque converter can quickly heat the fluid.

[Mike G]

Did the Scangauge easily pick up the transmission temps, or did you have to enter some custom codes or do anything special? I ask because in the past model years of Toyotas the tranny temps weren't readily readable, as I understand it.

[Doug2000]

Originally Posted by Mike G

Did the Scangauge easily pick up the transmission temps, or did you have to enter some custom codes or do anything special? I ask because in the past model years of Toyotas the tranny temps weren't readily readable, as I understand it.

I picked up the code on the 4Runner forum, someone had a full write up, that was last year. It really taught me how to drive in OD without heating up the transmission. I could buy a full size truck, but at the time my wife said she wouldn’t drive it and oh, the gas mileage. I compared gas mileage among the trucks on the website Fuelly, and that was another reason I bought the 4RUNNER.

[disneydoc]

A very informative thread, I wonder above applies to 2017 Highlander XLE, which is a unibody & a front Wheel Drive.

Thanks for sharing Doug

[John in Santa Cruz]

a cheap alternative to scangauge is a generic ELM 327 bluetooth adapter, and the inexpensive android app TorquePro running on a phone or tablet... this can monitor most any parameter accessible by your car's engine control unit (ECU), typically including transmission temps on automatics.

I monitor the torque converter lockup and gear I'm in too, that way I learned when it was locked vs not, and that on my 2002 F250 diesel, it will lock in 3rd or 4th(OD), and stay locked until it is ready to shift. 3-4 upshifts under light throttle, it stays locked, ditto 4-3 downshifts under minimal throttle, but 4-3 downshifts under full power, it will NOT lock til you back off.... after a few road trips of watching it, now I can just watch the tach and know whats going on... basically if it does a 4-3 downshift on a grade, I back off on the throttle for a sec, the RPMs drop to the locked-in-3rd, then I can reapply power, and it stays in 3 locked, smooth as can be. or if I intentionally put it in 3rd before I hit the steepest part of the grade, it will generally stay locked since I do that with minimal throttle. as long as the TC stays locked, the transmission doesn't heat up at all.

with this F250 diesel, going a steady 60MPH, i'm doing about 1700 rpm in 4th with the TC locked, and 2000 rpm or so in 3rd locked. 3rd unlocked might spin as high as 2500 rpm at the same 60 MPH

of course, ever vehicle is different, and the newer they are, the more 'smarts' they have to try and outsmart you...

[wetzk]

Another reasonably priced alternative is an Ultragauge MX.
It is capable of monitoring pages of info or as little as one item.
Among the items we monitor are Transmission Pan and Torque converter temperatures and torque converter lock and unlock. I set alarms if Pan temperature exceeds 205 degrees F or Torque converter exceeds 225 degrees F. The torque converter temperature will quickly start climbing, the pan temperature is slower to respond. The torque converter temperature is always higher than the pans so I watch to make sure things are not getting to hot. I found when the pan temperature was above 205 the torque converter was exceeding 220 at times. The alarms help so I do not have to look all the time.

[John in Santa Cruz]

i'm unclear as to what transmission monitors a Toyota 4.0L has, my Tacoma is a 6-speed stick shift... The factory sensor on the 4R100 automatic in my 2002 F250 diesel is embedded in the solenoid/valve block assembly... I just use the readings via forscan or torquepro for a relative idea... It usually reads around 180-190F on a hot day cruising on the highway... if it goes up to like 220, i back off. once I figured out those TC lock tricks I describe above, I've had no further issues with hot transmission.

[Viajante]

Originally Posted by John in Santa Cruz

a cheap alternative to scangauge is a generic ELM 327 bluetooth adapter, and the inexpensive android app TorquePro running on a phone or tablet... this can monitor most any parameter accessible by your car's engine control unit (ECU), typically including transmission temps on automatics.

I use TorquePro. The second transmission sensor is accessible by entering a custom code which I got from the 4Runner forum.