Tall Tow-Rig Tire Tech

I don't suspect that this will directly impact many of you, but I thought that the information might be usefull to some and it may spure other questions when you guys are getting new tires for your vehicles.

I have an Excusion that had 38's and recently put a set of Goodyear MTR 40's on it. In the process of looking into tires for this truck several things were important to me:
1. Size, this is typically the first thing that people look at and many times the ONLY thing that people consider when buying new tires. When you get to 40's you don't have as much choice between manufacturers and wheel sizes so your choices are limited. Keep in mind that the "real" size of the tire may also be significantly different than the "labeled" size of the tire also.

2. Load rating, My 38's were Load rated "E" and since this truck is heavy and tows regularly the load rating and the load weight capability were important to me.

3. Weight, some tires weight significantly more than other tires of the same size and most don't advertise these weights without signficant research.

4. Reviews, how others with the same tire in similar applications felt like the tire performed is of significant value. What many people forget with regard to reviews is that they should be similar applications and that everyone has a different experience level with a particular tire.

5. Price, It is not unusual to find price discrepancies of more than 50% between different tire companies for the same size tires.

For my particular application this was not an easy decision. Since I was purchasing new wheels I had a little more option of tire choices; BFGoodrich KM2's, Goodyear MTR's, IROK, and Toyo MT.

Here is how I narrowed down my choices.
1. The Toyo's were both exceptionally heavy and expensive, plus everyone has these on their lifted SD's already.
2. The BFG KM2's in this size are significantly more money than the others and weighed more than the MTR's.
3. The IROK has a SIGNIFICANTLY higher weight rating (load rated "E") and were less money than the MTR, and many people say they are an acceptable road tire on tow rig's. My concern was their weight and road maners and how they perform on snow/ice.
4. The MTR was reasonably priced, less weight than the others but was a load rated "C" tire which considering my experience towing with big tires did concern me.

In the end I decided on the MTR. The sales guys convinced me that the tire load was adaquate for what I was doing with the tires (it is within a couple hundred pounds of the 38's "E" that I was replacing).

When I installed them and aired them up I was in shock. Something I had never even thought to consider was the tire pressure that they are recommended to run at for max load capability. In the case of my previouse 38's it was 65psi and the MTR's it is 35psi!! Which means that I am getting "almost" the same load capability of the old tires at just over 1/2 of the tire pressure.

The first drive in these tires was incredible!!
1. The lower tire pressure is a very "soft" ride.
2. The tires track much nicer (this is probably just due to new tires instead of old tires).
3. These tires are much quieter than the old tires.

I now have about 2000 miles of towing on these tires and I must say that so far I am impressed and very happy with the decision. I still have two significant areas that I am interested to see how they perform; snow/ice performance (which I won't be able to see till winter), and how they hold up over time (tread wear and inner carcas strength) and obviously this will take a long time to understand better.

I just thought that I would pass on the info, some of you might find this usefull for your tires selections in the future.

Michael

so how big of a drop hitch do you have?

redneckboarder said:

so how big of a drop hitch do you have?

Click to expand...

I have a 12" drop hitch for my 20ft car hauler but I am only useing 10" of it currently.

I use a 8" Drop receiver and adjustable 8" drop hitch for my smaller trailers.

both are rated at 10K

Michael

I assume you have the new MT/R?

-Alex

Ba-Riedo said:

I assume you have the new MT/R?

-Alex

Click to expand...

Yes.

Where's the pictures?

good to read. i will be picking up an excursion at the beginning of the year and plan to start out with a small lift and possibly some 35"s. i plan to use if for towing and i was always under the impression that if you tow, always use E rated tires.

nw-xj-scott said:

good to read. i will be picking up an excursion at the beginning of the year and plan to start out with a small lift and possibly some 35"s. i plan to use if for towing and i was always under the impression that if you tow, always use E rated tires.

Click to expand...

At that size of tire you might have to, depending on the weight of the truck, load, and trailer.

Keep in mind that as a tire get's larger in size it usually has more weight capacity than a smaller tire, or higher weight capacity at a lower psi. So you will want to check that specifically for a 35 when you get ready to look at tires.

Michael

I will load some pics soon.

I'd like to throw a few thoughts on air pressure in here:

When towing, make sure the rear tires are AT the manufacturers recommended pressure.

Geico wrote up $3900 in damages to my tow rig from a blown rear tire.... :tears:

Michael where are the pics??

Good info on the tires.
I gotta say, I have never understood the reasoning behind lifting a tow rig. There are so many disadvantages to doing that and I think they far outweigh the advantages. Do you actually like towing with 40's or do you just tolerate it?

I'll get pic's up soon, it really doesn't look much different on 40's than it did on 38's in a photo.

I agree that there really are not very many practical reasons for lifting most vehicles (even strickly off road vehicles). Most of the disadvantages of towing with a lifted rig are pretty minor to deal with (I am more cautious on down hill winding passes than I would be if it was not lifted) most of the disadvantages are pretty easy to overcome with a little bit of experience with the rig. On the other hand this rig was originally built as a tow rig (that was it's original purpose, and it may perform significnatly better at it than other lifted rig's, I honestly have not driven that many of them to compare).

For me, the benefit of personal expression outweights the disadvantages of it being lifted.

Michael

XJ_ranger said:

I'd like to throw a few thoughts on air pressure in here:

When towing, make sure the rear tires are AT the manufacturers recommended pressure.

Geico wrote up $3900 in damages to my tow rig from a blown rear tire.... :tears:

Click to expand...

Good point Opie, It should be common sense to run tires at max tire pressure when they need it, and it should also be common sense to check the tire pressure regularly. Having said that, many people don't.

I check both the tow rig and trailer tires before "almost" every use, and I always run the tires at max cold pressure.

Tires can do A LOT of damage when they come apart!!

Michael

i have seen some pretty bad looking accidents because of real real big lifted rigs towing. Ya it looks cool but not exactly real safe. On the other hand a excursion on 40's with the 7.3 is my dream tow rig!

dellstopjeep said:

i have seen some pretty bad looking accidents because of real real big lifted rigs towing. Ya it looks cool but not exactly real safe. On the other hand a excursion on 40's with the 7.3 is my dream tow rig!

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Thats funny. ALL of the accidents I have seen have been with stock vehicles (towing and not towing). Does that mean that stock vehicles are not as safe as lifted trucks

So out of curiosity what would be unsafe about towing with a lifted rig anyway?

Michael

2xtreme said:

So out of curiosity what would be unsafe about towing with a lifted rig anyway?

Michael

Click to expand...

1. Higher center of gravity ( sane driving pretty much removes this as a major risk)

2. The higher you are the longer you have to fall in the event something fails (proper maintenance greatly cuts the risk.)

2xtreme said:

So out of curiosity what would be unsafe about towing with a lifted rig anyway?

Click to expand...

-----Matt-----

I hope Michael's being facetious. The higher center of gravity is the biggest factor. Steering corrections at highway speed lead to more sway on a lifted rig. This is usually fine as long as things like anti-sway bars and tire pressure are all good to go, but it is a factor regardless. A longer, wider rig will be more stable whether it's lifted or not, but lifting anything decreases it's stability as the COG is higher and will factor into how it reacts to sudden steering corrections at speed. Similar to a sky-high lifted rig on the trail, it will lean more and be more prone to flopping or even going over end to end on steep ascents and descents.

I still wanna see pics.

Torque.... The longer the drop hitch, the more multiplied the torque onto receiver. I know a guy that had a problem with this....his Jeep cartwheeled down Main Street in Puyallup, IIRC.