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Old 04-04-2005, 01:20 PM   #1
Hondo
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Default Toyota 4Runner

I have a similar question. I want to know what is the longest Trailmanor that you would be comfortable recommending me to tow. I have a 2003 4Runner with the 4.7 V-8, rear wheel drive, and 5 speed auto. My only towing experiences are towing 1) a 17 ft. fiberglas center console boat with a 115 hp. motor. I was traveling behind a friend pulling an identical boat with a 98 350 Tahoe and my TV combo was "faster" up the hills because of the gearing (IMHO). I was very comfortable even at the high speeds that my crazy friend drove. 2) When my son blew a head gasket on his extended cab 4X4 Toyota Tacoma, I pulled it on a Uhaul trailer. A sign on the trailer said the trailer weighed 2000 pounds. I estimate that the combo weighed 6000+. I was not comfortable with this over 45mph on a back road. The TV would pull it, and the TV would stop it, but I wasn't real sure which was in charge- the TV or trailer. I think that the 4Runner is rated to tow 6000 or 6500.
Secondly, what advantage if any is there in towing with a 5 over a 4 speed automatic?
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Old 04-04-2005, 03:01 PM   #2
Cobra500
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I cant comment on the 4-runner's towing capabilities, but a 5-sp auto helps to keep your engine in the best torque range (less lugging), also, they often have a lower first gear that helps get a heavy load rolling.

The Tm should stop much better than a boat or the auto/trailer you mentioned- the trailer has electric brakes.
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Old 04-04-2005, 03:14 PM   #3
RockyMtnRay
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Default 3023, maybe 3124 if mostly flat terrain, 2720 series or 2619 if mostly mountains

Quote:
Originally Posted by Hondo
I have a similar question. I want to know what is the longest Trailmanor that you would be comfortable recommending me to tow. I have a 2003 4Runner with the 4.7 V-8, rear wheel drive, and 5 speed auto. My only towing experiences are towing 1) a 17 ft. fiberglas center console boat with a 115 hp. motor. I was traveling behind a friend pulling an identical boat with a 98 350 Tahoe and my TV combo was "faster" up the hills because of the gearing (IMHO). I was very comfortable even at the high speeds that my crazy friend drove. 2) When my son blew a head gasket on his extended cab 4X4 Toyota Tacoma, I pulled it on a Uhaul trailer. A sign on the trailer said the trailer weighed 2000 pounds. I estimate that the combo weighed 6000+. I was not comfortable with this over 45mph on a back road. The TV would pull it, and the TV would stop it, but I wasn't real sure which was in charge- the TV or trailer. I think that the 4Runner is rated to tow 6000 or 6500.
Secondly, what advantage if any is there in towing with a 5 over a 4 speed automatic?
The biggest limitation you will have is the relatively short (~110 inch) wheelbase. Therefore you shouldn't go over a 23 or 24 foot TM (3023 or 3124) and would have a substantially greater margin of control with a 20/19 foot (2720, 2720SL, 2720SD, 2619). If towing on mountain roads, you really should stay with the 2720 or 2619 models.

Tow Vehicle Wheelbase is the critical element in being able to control your trailer...especially on sharply curving mountain roads (particularly where the curve also involves a steep descent) and also when you have strong gusting crosswinds or you hit the bowwave coming off a semi (particularly in combination with a strong crosswind).

Your 4Runner's power train is basically the same as my Tundra's (except you have a 5 speed tranny) which means you will be able to tow at the speed limit even in the high and steep Rockies/Sierra.

Cobra500's answer regarding the advantage of the 5 speed is spot-on.
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I use my TM as a base camp for hiking, kayaking, mountain biking, and climbing Colorado's 14ers


The Trailer: 2002 TM Model 2720SL ( Mods: Solar Panels (170 Watts), Dual T-105 Batteries, Electric Tongue Jack, Side AC, Programmable Thermostat, Doran TP Monitor System)

The Tow Vehicle: 2003 Toyota Tundra V8 SR5 4X4 w/Tow Package (Towing & Performance Mods: JBA Headers, Gibson Muffler, 4.30 gears, Michelin LTX M/S Tires, Prodigy Brake Controller, Transmission Temperature Gauge)


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Old 04-04-2005, 06:58 PM   #4
fcatwo
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It's rare that I have an opportunity to add anything to what Ray has said but an important point that hasn't been mentioned in this and other recent discussions so far is "rear-overhang" (distance from rear axle to hitch). Given two vehicles with the same wheel base, the one with the least distance from the rear axle to the hitch will be the most resistent to sway and probably the better TV.
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Old 04-04-2005, 08:48 PM   #5
Bill
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Frank -

Re "rear overhang" - an interesting term, and it describes quite well exactly what you mean. Tell me, is it in common usage (meaning I could find it on Google) or is it your own invention? Either way, I like it, and will use it in the future. As you note, this is a consideration that we haven't explicitly taken into account in earlier discussions.

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Old 04-04-2005, 09:04 PM   #6
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Yep, a real typo that was. I corrected it. Thanks for pointing it out.
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Old 04-05-2005, 07:56 AM   #7
RockyMtnRay
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Default Excellent Point!

Quote:
Originally Posted by fcatwo
It's rare that I have an opportunity to add anything to what Ray has said but an important point that hasn't been mentioned in this and other recent discussions so far is "rear-overhang" (distance from rear axle to hitch). Given two vehicles with the same wheel base, the one with the least distance from the rear axle to the hitch will be the most resistent to sway and probably the better TV.
Yes, rear overhang is a measurement I've been quasi-ignoring...in part because it's almost impossible to find out what it is for a given vehicle (not a normally published "spec"). And yes, it's very important...actually the ratio of wheelbase to rear overhang is the critical number as this ratio is an excellent indicator of how well the tow vehicle can resist trailer sway. This ratio is also the key factor in how much unweighting of the front suspension will occur when the trailer is hooked up without a WDH.

That all being said, rear overhang is typically about 3 feet for most mid size SUVs and about 4 feet for typical half ton pickups...and those are the approximate numbers I use when predicting the amount of front unweighting that has to be combatted by a WDH.
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I use my TM as a base camp for hiking, kayaking, mountain biking, and climbing Colorado's 14ers


The Trailer: 2002 TM Model 2720SL ( Mods: Solar Panels (170 Watts), Dual T-105 Batteries, Electric Tongue Jack, Side AC, Programmable Thermostat, Doran TP Monitor System)

The Tow Vehicle: 2003 Toyota Tundra V8 SR5 4X4 w/Tow Package (Towing & Performance Mods: JBA Headers, Gibson Muffler, 4.30 gears, Michelin LTX M/S Tires, Prodigy Brake Controller, Transmission Temperature Gauge)


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Old 04-05-2005, 09:22 AM   #8
Cobra500
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I'd guess the type of rear suspension is as important (or more) than the axle to hitch length.

Some "performance" suspension designs (with lots of wheel travel) allow more side to side movement than others- a panhard bar would help to control lateral movement as much as anything. Soft coil springs (independant suspension/ McPherson struts) are probably bad, leaf springs with overload supports possibly better.

My guess is that simple leaf designs with stiffer springs are what make pickups better tow vehicles than many SUVs with softer springs. Your overhang theory would suggest SUVs are 25% more stable while towing???

Many foreign SUV suspensions are closer to car designs (designed more for comfort than utility) than the more rugged US designs that evolved from (heavier) pickups- Im sure exceptons exist on both sides.
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Old 04-05-2005, 03:59 PM   #9
RockyMtnRay
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Default Suspension type has less effect than tire type

Quote:
Originally Posted by Cobra500
I'd guess the type of rear suspension is as important (or more) than the axle to hitch length.
It would be a very, very bad suspension to have equal importance...yes, some suspensions have lateral movement but it's unlikely to be more than half an inch...which is about the same lateral flex in the sidewalls of P series tires.

Quote:
Some "performance" suspension designs (with lots of wheel travel) allow more side to side movement than others- a panhard bar would help to control lateral movement as much as anything. Soft coil springs (independant suspension/ McPherson struts) are probably bad, leaf springs with overload supports possibly better.
Worst case would be coils on a live axle with a panhard rod. All independent suspensions (including McPherson or other strut designs) use a lower control arm where the only lateral movement will be the minor amount allowed by the arm's pivot bushings.
Quote:
My guess is that simple leaf designs with stiffer springs are what make pickups better tow vehicles than many SUVs with softer springs. Your overhang theory would suggest SUVs are 25% more stable while towing???
No, not even close to a 25% difference. It''s not the overhang itself but the ratio of wheelbase to overhang...and the higher the ratio, the greater leverage the steering can exert.

Typical midsize SUVs have wheelbases in the 110 to 120 inch range and an overhang of about 36 inches. Typical half ton trucks have wheelbases between about 130 and 150 inches and an overhang of about 48 inches. That computes to a steering leverage ratio of about 3.2 for a 115 inch wheelbase SUV and a leverage ratio 2.91 for a 140 inch wheelbase truck...a slight (10%) advantage for the SUV...but if that SUV had just 4 more inches of overhang, it's ratio would be 2.88. And if the truck had just 4 inches less, it's ratio would be 3.18. Real hard to derive any cross-the-board differentiation between SUVs and pickups on this factor.

However, trucks tend to have more front weight bias (when lightly loaded)...which improves steering control...and they also usually have LT tires with stiffer sidewalls...a factor that definitely improves lateral stability when towing.

In any case, I've yet to see any conclusive, widely reported evidence that pickups make better tow vehicles for travel trailers than equivalent sized SUVs...or vice versa. I've also not seen any widely reported conclusions that different types of suspension make a huge difference in towing stability. I have, however, seen a number of anecdotal reports that suggest that stiffer sidewall tires (in particularly "LT" light truck series tires) do make a noticeable difference in towing stability.

For a very indepth analysis of suspension, overhang/wheelbase ratio, and tire effects on towing, please read this post on the RV.NET towing forums. It was written by an RV dealer in Canada who has enormous amounts of experience and knowledge regarding what works and what does not work for trailer stability.

For instance, on the wheelbase/overhang ratio I keep harping on, he writes:

"What we have found is that we do not look at wheelbase alone but also its relationship to rear overhang so we measure the rear overhang as a percentage of the wheelbase. So a Front Drive van with 120" wheelbase and a 30" overhang has an overhang to wheelbase percentage of 25% where as a Suburban with a 131" wheelbase and a 49" rear overhang has an overhang percentage of 38%. An interesting comparison that I have found is a Suburban and a Tahoe that have identical suspension have equal overhang percentages when you use a welded ball mount. Even though the wheel base is 131.5 for the Suburban and 116 for the Tahoe if you connect identical trailers to both vehicles they will handle the same."

On SUVs (especially the import SUVs you don't seem to think much of) and independent suspensions, he writes:

"Some SUV’s work quite very well the BMW X5 and the Mercedies ML handle extremely well. Someone posted a picture of a Lexus RX300 /25' Airstream combination. I doubt many if any of the combinations that I see people here own could match it in stopping distance emergency handling or straight line stability in fact this combination will likely outperform most large trucks solo. Trust me the owner of this combination is very particular about the performance of his vehicles he has raced and owned some exotic sports cars. He is also in the position to tow with what ever he pleases

The new Ford Expedition and Explorer with independent rear suspension are also quite good if you get rid of the balloons they call tires."
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Ray

I use my TM as a base camp for hiking, kayaking, mountain biking, and climbing Colorado's 14ers


The Trailer: 2002 TM Model 2720SL ( Mods: Solar Panels (170 Watts), Dual T-105 Batteries, Electric Tongue Jack, Side AC, Programmable Thermostat, Doran TP Monitor System)

The Tow Vehicle: 2003 Toyota Tundra V8 SR5 4X4 w/Tow Package (Towing & Performance Mods: JBA Headers, Gibson Muffler, 4.30 gears, Michelin LTX M/S Tires, Prodigy Brake Controller, Transmission Temperature Gauge)


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Old 04-05-2005, 09:20 PM   #10
sandy eggo
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Default oh yeah...

Quote:
Originally Posted by RockyMtnRay
On SUVs (especially the import SUVs you don't seem to think much of) and independent suspensions, he writes:

[COLOR=Navy]"Some SUV’s work quite very well the BMW X5 and the Mercedies ML handle extremely well. Someone posted a picture of a Lexus RX300 /25' Airstream combination. I doubt many if any of the combinations that I see people here own could match it in stopping distance emergency handling or straight line stability in fact this combination will likely outperform most large trucks solo. COLOR]
Feeling nervous yet about that tractor-pull we keep talking about, Ray?
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