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Med Duty tow rig questions

NTORACN
Explorer
Explorer
I'm looking at retiring in the next 5 years or so and I'm just starting to look at possibly using a medium duty rig to tow a custom built toy hauler that has yet to be built. The 5th wheel that I'm thinking of having built will be in the 35' range and have the capability of hauling my restored, mostly stock 1980 FJ40 Land Cruiser that is exactly 2 tons. I am looking at something like an International 4700 Lo Pro type of tow rig. I want the Allison auto so the wife can drive so in an emergency situation. What engine make and HP level should I be looking for to get decent power and fuel economy? What rear end ratio is best for pulling and fuel economy? Any particular outfits I should stay away from and why?

Thanks for all your help in advance.

Randy
33 REPLIES 33

SoCalDesertRid1
Explorer
Explorer
Most MDT with air brakes are 26,000-36,000 GVWR. Most without air brakes are 19,000-26,000.
01 International 4800 4x4 CrewCab DT466E Allison MD3060
69Bronco 86Samurai 85ATC250R 89CR500
98Ranger 96Tacoma
20' BigTex flatbed
8' truck camper, 14' Aristocrat TT
73 Kona 17' ski boat & Mercury 1150TB
92F350 CrewCab 4x4 351/C6 285 BFG AT 4.56 & LockRite rear

bigg-limo
Explorer
Explorer
carringb wrote:
BigBaron wrote:

Many I've "met" there had an MDT and it wasn't enough, especially after they got a bigger trailer.

Here's an MDT that he is going to have to upgrade because his new trailer is too heavy.

:h

I don't see how an RV trailer could overload an M2. Rear axle is rated for 20,000 pounds (they offer higher, but you need an overweight permit to utilize those on the highway) and combined weight up to 80,000 pounds.

An HDT that is singled out will have less pin weight capacity because you still can't go over 20,000 pounds on an axle, but the tare weight of the HDT will be higher.


From experience, the MDT is not overloaded from a weight capacity standpoint,…it usually ends up being the performance that a lot of people are unhappy with. Yes, the HDTs have bigger and better braking,…no doubt about that. The problem is that it takes you much longer to accelerate. Another problem is that you have an 18k lb trailer that slows you from 60+ mph on a 6% grade, all the way down to 30-35mph. That's why I love my 525hp motor that sits under my hood. I mostly only drive 60 or 65 mph when I'm towing my trailer. There have been times when i have been stuck behind semis, and have been able to switch lanes and accelerate to pass them on a those 6% grades. When I used to have my MDT, I would always get stuck behind them, or they would pass me on the hills. While my MDT was dropping down to that speed, it was always working the engine pretty hard too.

Something to think about as far as the weights and axle ratings are concerned,…most of the MDTs only gross about 19.5k lbs. They average about 13k lbs by themselves. That would leave you with 6k+ lbs for payload or pin weight. That's about what I'm working with on my HDT.

bigg-limo
Explorer
Explorer
hone eagle wrote:
NTORACN wrote:
HDT's are good affordable, powerful tow rigs. However, feeding a 10 liter engine yields about 5 or 6 MPG. I think an MDT will yield around 10 or 11 MPG and is overbuilt for the 20 to 25,000 Lbs my loaded trailer will probably weigh. Thanks for the advice.

Dennis M M wrote:
Personally I think you will be way better off looking at a HDT instead of an MDT.

Much greater capability and a lower cost of entry.

Do some reading on the Heavy Duty Truck Forum


Not true ,most do close to 8-9 mpg
Mine runs 9.5 on a U.S. gallon


Mine gets 9.5+ running 60 mph,…and that's with a 15L motor.

BigBaron
Explorer
Explorer
Actually an HDT is cheaper than an MDT. I know of a sweet Peterbilt with a car deck that is $30K right now. MDTs are around $60K and up.

That big brown trailer is around 33,000 lbs. and well over $200K if I remember correctly. The MDT that pulls it has a 9-liter engine. It pulls it just fine, but works hard on hills.

The Heavy Hauler Resource Guide is a great source for info. It's also fun to read!
Baron, Julie, Lil' Barry, Faith and OSD, Fang
'03 Hyundai Starex(H1) 2012 Coachmen Clipper Sport 126
Incheon, S. Korea
From six months of no camping to having a winter site 30 minutes from a ski resort! I'm a happy camper!

bmanning
Explorer
Explorer
BigBaron wrote:
Escapee's HDT forum is good, too.

Many I've "met" there had an MDT and it wasn't enough, especially after they got a bigger trailer.

Here's an MDT that he is going to have to upgrade because his new trailer is too heavy.



Absolutely drooling over that truck! If I won the lottery I'd buy almost that exact truck (singled w/ sleeper), get a CDL, and yank RV's, boats, and other loads around the country just for fun.

(Remember, I won the lottery, so profit margin is unimportant LOL)
BManning
baking in Phoenix :C
-2007 Volvo XC90 AWD V8
4.4L 311/325 V8 6sp Aisin loaded
6100lb GVW 5000lb tow
-1999 Land Cruiser
4.7L 230/320 V8 4sp A343 loaded
6860 GVW 6500lb tow
RV'less at the moment

carringb
Explorer
Explorer
BigBaron wrote:

Many I've "met" there had an MDT and it wasn't enough, especially after they got a bigger trailer.

Here's an MDT that he is going to have to upgrade because his new trailer is too heavy.

:h

I don't see how an RV trailer could overload an M2. Rear axle is rated for 20,000 pounds (they offer higher, but you need an overweight permit to utilize those on the highway) and combined weight up to 80,000 pounds.

An HDT that is singled out will have less pin weight capacity because you still can't go over 20,000 pounds on an axle, but the tare weight of the HDT will be higher.
2000 Ford E450 V10 VAN! 450,000+ miles
2014 ORV really big trailer
2015 Ford Focus ST

NTORACN
Explorer
Explorer
THANK YOU for everyone's help and info. I know a modern 1 ton dually could get the job done, but I prefer not to operate at the weight limits of the truck. MDT's and HDT's are over built for what I need it for and should be a pleasure to drive because it won't be maxed out.

Have a good one.

stripit
Explorer
Explorer
I have a 1999 International 4700 low Pro with the Stalic box. I bought it used in 2002 with 40,000 and it now has 110,000. In all that time and miles I have replaced 1 water pump, 1 relay,a set of batteries, a set of shocks and 1 small gasket to stop a oil leak. It needs tires and they will be replaced in the spring. It has been as close to bullet proof as a truck can be. It has the 4:44 rear axle and the International 530 cube 300 hp with the Allison 6 speed and 22.5 tires. Perfect combo for anyone to drive. It does slow down going up some elevations but that is the way it runs, never over heats and no signs of it wanting to not make it up the mountain. Over all this time the average fuel consumption is 7.5 and most all the driving was towing my 17,500 trailer. When I was full time the truck weighed 14,100 lbs without the 4,400 lb pin weight added.I'm sure now the value is close to nil on a truck of this age and mileage, but at the time it was the truck we needed to safely STOP my rolling house. Most anything would pull that trailer, but stopping was my main concern. It has huge disc hydraulic brakes at all four corners. No air brakes and I know it was an option at the time of build, the previous owner opted not to have them.
Stacey Frank
2016 Tiffin Allegro Bus 40AP
2019 Tesla Model X
2015 Cadillac SRX we Tow
1991 Avanti Convertible

BigBaron
Explorer
Explorer
Escapee's HDT forum is good, too.

Many I've "met" there had an MDT and it wasn't enough, especially after they got a bigger trailer.

Here's an MDT that he is going to have to upgrade because his new trailer is too heavy.

Baron, Julie, Lil' Barry, Faith and OSD, Fang
'03 Hyundai Starex(H1) 2012 Coachmen Clipper Sport 126
Incheon, S. Korea
From six months of no camping to having a winter site 30 minutes from a ski resort! I'm a happy camper!

hone_eagle
Explorer
Explorer
NTORACN wrote:
Thanks for the info Hone Eagle.

Does having air brakes in a non commercial application require a class A license? Not sure if the little woman would want to learn shifting a road ranger tranny. I was also looking at using the MDT as a vehicle to drive around when at our destinations when not bringing my Landcruiser. Not sure if I would want to drive an HDT on city streets too much. Not that an MDT is as easy as a compact car to park, but seems to be a happy medium between the HDT and a LDT. I will revisit the HDT option again before rendering a decision.

Merry Christmas

hone eagle wrote:
NTORACN wrote:
HDT's are good affordable, powerful tow rigs. However, feeding a 10 liter engine yields about 5 or 6 MPG. I think an MDT will yield around 10 or 11 MPG and is overbuilt for the 20 to 25,000 Lbs my loaded trailer will probably weigh. Thanks for the advice.

Dennis M M wrote:
Personally I think you will be way better off looking at a HDT instead of an MDT.

Much greater capability and a lower cost of entry.

Do some reading on the Heavy Duty Truck Forum


Not true ,most do close to 8-9 mpg
Mine runs 9.5 on a U.S. gallon


Spend some time as suggested on the HDT forum
no 'class A or cdl' required ,they are either motorhomes or private plated mine is a motorhome and less to insure then my previous SD.
automated transmission, DW drives it bobtail- no clutch peddle.
cost per mile is the same as my old 7.3 because of the size of the tanks I can fuel in the cheapest state every 2000 miles or about once a season.
Come to one of the rallies for HDT's bring the wife if she thinks you are loon and meet the other ladies.
While you shop and drive MTD's ask the following -?
-how quiet is this MTD?,(my floor is 3" thick)
-are the doors double sealed that is 2 offset rubber gaskets on the perimeter?
-air bag suspension on ALL axles?
-air suspended cab?
-air suspended seats?
Those are some pro's ,there are also some cons ,head over to the escapees and read and read
many have come from MTD's and will recommend skipping them unless it meets a very specific need.
2005 Volvo 670 singled freedomline 12 speed
Newmar 34rsks 2008
Hensley trailersaver TSLB2H
directlink brake controller

-when overkill is cheaper-

Cummins12V98
Explorer III
Explorer III
NTORACN wrote:
A modern 1 ton truck would be at its limit at the weight I'm looking at. I would rather have a tow rig that right in the middle of its weight capacity versus at its limit. Have a good one.
Cummins12V98 wrote:
Any of the new 350/3500 trucks will be more then enough.


So you are looking to tow more than 30K? The new RAM's are fully capable of TOWING 30K.

MY combined is over 28K and it handles it with ease.
2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

carringb
Explorer
Explorer
The M2 is a great truck! I find it nearly pickup-like compared to an HDT. Ride is pretty good IMO with air-ride. As mentioned, the hybrid exhaust and engine 2-stage brake is a great feature.
2000 Ford E450 V10 VAN! 450,000+ miles
2014 ORV really big trailer
2015 Ford Focus ST

cwill925
Explorer
Explorer
2L Custom Trucks
Chuck Williams
2015 Raptor 412-TS
2006 Freightliner M2-112 Sportchassis
BMW K1600 GTL, Honda Rebel or a Smart Car in the Toyhauler.

cwill925
Explorer
Explorer
Truckpaper.com
Chuck Williams
2015 Raptor 412-TS
2006 Freightliner M2-112 Sportchassis
BMW K1600 GTL, Honda Rebel or a Smart Car in the Toyhauler.