Tow Vehicle Compatability

[Padgett]

About the steepest grade I've seen was the approach to the Thomas B. Manuel bridge in the turnpike.

Did cross the spine of Florida at Clermont (few miles of dramatic elevation changes) and the heep didn't even notice it bringing the TM home, just left in cruise.

6400 rpm redline and 4000 rpm torque peak means 55-65 in 2nd (of 5) is no problem with an overall gear ration of about 7:1. High winding modern engines can do a lot more with less if they have the right gears.

Personally for 2015 3-4 liters is the sweet engine size for a tow vehicle. With direct injection and boost, 2.5-3.5 liters. Key is to be able to stay out of PE.

[scrubjaysnest]

Originally Posted by kikeehn

Scrubjaysnest,
The 2WD Pilots tow rating is 2000 lbs and the 4WD is 4500, so if the Specs for the 2WD Isuzu are similar to the Pilot I could see the problem you had.

The 2WD 1999 Rodeo had a tow rating of 4500 FWIW

[scrubjaysnest]

Originally Posted by mecicon

I think you may have the info crossed with the Honda Passport which was the same as the Isuzu Rodeo and not the Honda Pilot.

The Pilot and Rodeo/Passport were not produced at the same time either.

http://en.wikipedia.org/wiki/Honda_Passport

http://en.wikipedia.org/wiki/Honda_Pilot

Since I have trouble remembering what I eat five minutes after leaving the table doesn't suprise me

[daveinfl]

I find almost every discussion about towing vehicles to be very frustrating. I have a 2011 Mercury Mariner. It is two wheel drive. My Trailmanor is a 2619. We towed it 3500 miles last summer from Florida to Branson, Mo. to Michigan and back to Florida. We had no problems at all. I found my sweet spot to be 60 mph. When going up hill it seemed to go no slower then many of the fifth wheels or larger travel trailers. Now sure I would love to have a 6000 towing capacity. But I can't afford it. And Trailmanor says my 2619 should tow fine behind my Mariner. So it just bothers me when someone asks a question about a TV with a 4500 pound tow rating and you hear everyone saying you need more. To me 4500 lbs for a 2720 should be fine. It certainly isn't a Ford F250 dually with 7500 lbs. towing capacity ... but should do the job well. For me, and I respect all of our opinions, I defer to what Trailmanor says.

[Bill]

Dave -

You are quite right for the towing you do. Florida to Missouri is basically flat terrain. Most of the comments are directed at folks who plan to tow in high mountains with steep grades. Although the tow vehicle manufacturers never mention it, the requirement placed on the tow vehicle for these two situations is quite different. This makes sense, I think you will agree - it is harder to pull a trailer up a steep hill for hours than it is to cruise along a flat turnpike for hours. That was the basic intent of J-2807 - to prevent manufacturers from cherry-picking their tow conditions when stating a rating.

Bill

[Padgett]

Have said before I've towed a lot more with a lot less. Key here is "if you have to ask" then we have to assume little experience and must provide a very conservative answer.

Mentioned before that I had a friend who towed a 69 T/A on a tandem trailer behind a S10 with a 2.8 and a 5 speed from California to Florida. Didn't say he had to rebuild the 2.8 almost immediately after.

Have mentioned that my 2720SL tows nicely behind my '12 Grand Cherokee with V6. Don't really need that much HP if you have the right gears. What you do need in a TV is a proper hitch (2" class III min with Bargman), rear axle that can handle a 400-500 lb tongue weight (TMs tend to be nose heavy, designed that way to be more stable), and enough cooling to keep oil and trans temps down (I tend to drive on the temp guage and can monitor coolant, oil, and trans temps on the road).

So for a newbie asking, I'd say 500 lb min tongue and 5000 lb hitch/axle rating with a factory towing package. Given that my measured tongue weight was 460 lbs I'd say a 450 lb rating would be "marginal".

OTOH if someone says "I have an X and can't afford something else but have done a lot of towing" then I'd look at the specs and advise what would be needed (and if the expected OAT is over 90 then more is good).

Does that make more sense ? Will admit that sometimes I/we just make an assumption from how the question is asked and have to consider that in Orlando at least the phone book has more lawyers than doctors.

ps I've never had a 4WD/AWD vehicle.

[scrubjaysnest]

Originally Posted by Bill

Dave -

You are quite right for the towing you do. Florida to Missouri is basically flat terrain. Most of the comments are directed at folks who plan to tow in high mountains with steep grades. Although the tow vehicle manufacturers never mention it, the requirement placed on the tow vehicle for these two situations is quite different. This makes sense, I think you will agree - it is harder to pull a trailer up a steep hill for hours than it is to cruise along a flat turnpike for hours. That was the basic intent of J-2807 - to prevent manufacturers from cherry-picking their tow conditions when stating a rating.

Bill

I agree Bill and I understand Dave's frustration but for our selves we don't travel the I-75 or I-95 corridor which is relatively flat. This past winter we crossed several 15% grades and I think the smaller TV's even with the lighter TM's would be well aware of the grade. Tampajohn found that out about a year ago. It's a case of what type of towing are you going to do.

Kikeehn is in AZ; if he stays south of Mesa on I-10 or I-8 that is fairly flat driving like FL. But north of there is a different story. Now you get into things like what is the TV weight compared to the TM. This can have the tail waging the dog. If you take our TM at 3680# that only leaves 920# margin for a tow rating of 4500#. Take 10% of that number which just about every 2720SL or SD will have for a tongue wt is 450#. That's 50# below what most bumpers are rated and class III hitches without a WDH.

[Roy in Texas]

I will offer a different opinion. I suggest you also look the available torque when considering a TV. It looks to me like the Honda Pilot V6 puts out about 250 ft-lbs of torque which should be ok. I mention this since torque is much more important and HP when considering towing performance.

I have towed my 2720 with a 2006 Honda Ridgeline and a 2004 Ford Excursion (both of which I recently sold and replaced with a 2015 RAM 1500 eco-diesel). The Honda V6 put out around 250 ft-lbs or torque. The Excursion about 550 ft-lbs. While the Honda was "adequate" in Texas and in most flat terrain, I did not like it at all in the mountains. The Excursion was a lot more TV than needed for a 2720. I had bought it when I had 9000 trailer and 4 kids.

In my experience, 250 ft-lbs will get you where you want to go, but you may only be able tow at 45-50 mph up steep grades.

I like being able to accelerate to pass slow moving vehicles and trucks going up steep grades in the mountains. For me, that means an engine that can produce 350-400 ft-lbs of torque. My new RAM 1500 3L eco-diesel produces 420 ft-lbs and is connected to an 8 gear transmission. Its overall tow rating is 9200 lbs. There are lots of other vehicles and engines that could have met my desires as well. We are planning a trip from San Antonio to Seattle in August and will spend 6-7 weeks in traveling around WA, OR, and northern CA.

Bill is right about the value of the new J-2807 standard in being able to compare the relative capabilities of different TVs. Many of the 2015 models are already using the standard. For example, here are the results posted by RAM.

http://www.autoblog.com/2014/07/16/r...fficial-video/

Others have covered the tongue weight and hitch issues which are also important.

[daveinfl]

I think the point of my post is that we don't want to totally scare people away. We should qualify - If your towing will be "in the mountains with grades of more than X%. If your towing will mainly be on interstates and in the flats such as Florida, Eastern Virginia, etc.

I admit ... I would never tow in the "heavy" rockies with my Mariners. But I would tow from Florida to Maine with my Mariner.

I think also important is how you load. I am still experimenting with that. But that is another thread. Thanks everyone. I have learned from ALL of you. And I hope a few have learned from something I have posted. Have a great day!

[Padgett]

Now we are getting into the heart of it and the math gets complex. Will say the Eco-diesel (now that it is no longer the ecto-diesel) is a marvelous design with one major caveat: like most diesels the 420 lb-ft torque is produced low down, peaking at 2000 rpm and dropping fast (by the hp peak at 3500 it has driopped unded 400 lb-ft).

OTOH the Pentastar 3.6l gas engine is within spitting distance of 250 lb-ft from 2000 to 6000 rpm. With the right gearing the tractive effort (power to the ground) of the gas engine can exceed that of the diesel.

Gearing is why that Jeep Wrangler Unlimited with a manual trans and the Pentastar had no trouble with their TM, particularly starting.

For me the other issue is that I like my Grand and have never had a pickup trick. Station wagons/minivans/SUVs just make more sense for my lifestyle and to get the diesel in a GC is a $10k hit over mine ($4.5k for the engine, $5.5k for mandatory upmodel & options)

Add in the fact that around here diesel is about 40% more expensive than 87 PON and for me it does not make sense even though I like and have had TDs in the past.

Here in 2015 one thing is clear that wasn't even in 2012: the future is direct injected boosted gas engines running on 87 PON. They are becoming available today and from the majors.

My point is that what is right for one person may not be for anyone else. Will abmit that when buying my GC back before they were popular, the towing capacity was an important factor and then if a diesel had been available I would have bought it. Today I am not so sure.

ps do understand transonic flow issues in hypergolic fueled motors.