4Runner SR5 V6 Towing

We have a 1997 4Runner SR5 V6, what would be the size limit so that we could comfortable tow a Trailmanor in the southern Colorado Rockies?

Thanks for your advice

[Denny_A]

Originally Posted by Rogregma

We have a 1997 4Runner SR5 V6, what would be the size limit so that we could comfortable tow a Trailmanor in the southern Colorado Rockies?

Thanks for your advice

I had a 2000 4Runner, SR5 V6, 4WD. If yours is also a 4WD, then this link should match your vehicles specs.

http://www.edmunds.com/used/1997/toy...enav..6.Toyota*

I towed a 2720SL. The 5000 lb towing limit was fine for me. The limited max torque of 217 lb-ft is fine east of the rockies, and probably not acceptable if climbing into higher elevation terrain.

In theory, its 5k capacity should handle any TM. In reality, I wouldn't have wanted to tow a nearly 5000 lb 3326,or even a 3124 in the flatlands, much less the mountains. All other TM's should tow just fine. My average MPG, towing a 2720SL was around 14. Some hilly terrain, but mostly flatland towing!

To have even half a chance for acceptable towing in the Rockies, you'll probably need nearly 280+ lb-ft of torque and a proper axle gear ratio. I trust that RockyMountainRay will weigh in soon. He's the resident Colorado mountain man.

Denny_A

I have a 1999 4-runner with 3124ks and constantly go up I-70 with it. The steep grades will definately slow you down. 7% grade will slow you down to 30-35mph with a 6 cyl. This includes wolf creek pass in southern Colorado and on 1-70.
The things to remember on a 4-runner is to take the overdrive off and leave it off. Make sure you have a sufficient transmission cooler. The coolers with the built in tow package is sufficient---"Part of the radiator".
If not, it should be a heavy duty one...
Make sure you have a good brake controller.. eg. protegy, because the brakes will get hot very quickly. 4-runners have thinner rotors. Use your engine braking often.
You will also need an equalizer hitch. I have the equalizer brand 1000 lb. and it works very well on the 4-runner.. If you don't, your headlights will be in the trees.
The SUV works very well towing a 3124ks on normal freeways that are 4% incline or less.

[RockyMtnRay]

Originally Posted by Rogregma

We have a 1997 4Runner SR5 V6, what would be the size limit so that we could comfortable tow a Trailmanor in the southern Colorado Rockies?

Thanks for your advice

"Comfortable towing" is a subjective term and depends greatly on how you define it. If you define it as having a tow vehicle that can stay with traffic when pulling a trailer up the steepest and highest mountain grades...or not being the slightest bit affected by winds when towing...or being able to make an emergency maneuver with aplomb even with trailer in tow...then your 4Runner is just not powerful enough nor does it have enough wheelbase to tow a TM of any size. On the other hand, if you define "comfortable towing" as being able to eventually (maybe at 25 - 35 mph) get your trailer to the top of mountain grades without destroying your engine/transmission (even if done regularly)...or being able survive strong cross winds/emergency maneuvers with some "white knuckle" time, then your '97 4Runner may suffice for a couple of years with a TM 2619 or 2720.

There are 3 key numbers that determine how well a tow vehicle will work for towing here in the Colorado Rockies. The first and most important is the engine's maximum torque. According to the sources I checked, your engine puts out a modest 217 ft-lbs of torque at 3,600 rpm and is hooked to a 4 speed (w overdrive) automatic. The second key number is your axle ratio...unless you have the special locking rear differential, indications are you have a 3.73 gear ratio in your differential(s). A 3.73 axle means your engine will be only turning about 2400 RPM at 65 mph with overdrive off...and that's a long way below the peak torque RPM of 3600. I'd estimate you'll only have 150 ft-lbs of torque available with transmission in 3rd gear at normal highway speeds...and that's at sea level. At 6000 feet of elevation, you'll have about 80% of that..or only 120 ft-lbs. And at 11,000 feet (the approximate altitude of most passes over the Continental Divide in Colorado), you'll only have about 60% of that...or only about 90 ft-lbs.

What those numbers mean is that you'll have the transmssion down in 1st or 2nd gear...and the engine revving around 4000 RPM....just to hold about 30 mph everytime you cross a pass...and you'll be crawling at that speed and listening to the engine roaring at that RPM for miles and miles. You'll also be down to 40 to 45 mph even climbing a slight grade (anything over about 3%) at elevations above 6000 feet.

The final key figure is your 4Runner's wheelbase...a very short 105.3 inches. Tow vehicle wheelbase relative to trailer length is the key factor in how well the tow vehicle can resist trailer induced motion (sway) and control the rig in cross winds and during emergency maneuvers (sharp steering inputs)...and longer is much better. I orginally towed my TM 2720SL with a short (100 inch) wheelbase Jeep Cherokee and now tow it with a longer (128 inch) wheelbase Toyota Tundra. The difference in towing stability...and towing comfort...between these vehicles was dramatic. An emergency maneuver with the Jeep was always right on the edge of control whereas one with the Tundra is essentially a non-event.

When you consider the very modest towing torque of your 4Runner...and its short wheelbase, the biggest TM you should ever consider towing with a modicum of comfort is a 2720. Although a TM 3023 has an empty weight that's just a couple of hundred pounds more than a 2720, it is substantially longer and has a lot more storage capability for "stuff". And it's that "stuff" that will really up your trailer's actual weight.

And to be honest, once you get even a 2720 you need to be prepared to be setting money aside for an upgrade to a longer wheelbase and substantially more powerful tow vehicle. If you want to stay in the Toyota SUV family (a good idea), start thinking about trading the 4Runner for a V8 Sequoia.

P.S. After making literally dozens of crossings of the Colorado mountains with my TM in tow...and after spending literally thousands of $ to enhance the excellent stock performance of my 4.7L V8 Tundra, I've concluded that "happy and comfortable" mountain towing of a TM (4000 lbs or less) in Colorado means an engine with at least 350 ft-lbs of torque (at 3200 RPM or less) combined with an axle ratio of 4.10 or lower (numerically higher). With exhaust modifications (headers and muffler), my truck's engine is producing about 350 ft-lbs of torque at 3200 RPM...which is transferred to the tires via differentials regeared with 4.30 gears. The combination works superbly for towing...except on the very steepest/highest grades, I hardly ever have downshifts to 2nd gear. I can easily stay with traffic (car, not just RV/truck) on the steepest grades...and maintain or exceed the speed limit on those grades. Basically, mountain towing is now not just comfortable but actually downright enjoyable...something to be looked forward to instead of dreaded.