RF and tech,
I know this is a stupid question but since my brain has been overloaded lately I'm going to ask. Also wanted to take this out of the other thread we've been conversing on since this isn't related to the original question.

I've been unable to find a schedule that gives the actual towing capacities based off of engine, cab config, axle gearing, etc., like you can with the 2500/3500's. Does such a schedule exist? http://www.dieselplace.com/forum/images/smilies/confused.gif

Tech, what rear end ratio does your rig have? RF, what average speed are your mileage numbers from? Would also like to know what RPM numbers your both at. It seems to me, that the taller rear ends get better mileage by allowing the engine to rev a little more while towing. I've noticed this once when I took it up to 70 that the DIC was showing better MPG numbers. No JJ, I don't trust the DIC for figureing mileage! I normally drive 60-65 with the trailer as I'm uncomfortable at anything faster.

RF,
Also wanted to clarify that I'm not looking for "Mudder" type tires, just something that fit's the wheel wells proportionately better. Whether this means shrinking the wheels wells or installing a tire that fills it better. This of course, is a personal preference!

While I agree that the 4/5 series is a better equipped to handle the trailers we all seem to be towing, I don't feel it's the the best size for a daily commuter (this is my personal preference of course). This is were I feel the F**d exceeds.

I also understand the "dry weight" labeling, but trailers also come from the factory with a second label that is supposed to state the "corrected weight" with factory installed options. Mine was a lot more than a couple of hundred pounds off.

Now if anyone thinks I'm attacking or coming off defensively, I'm not and appologize. My intent here is nothing more than sharing what little I know, gaining a little more from others and hopefully, making new friends!

One more thing RF, Good luck on affording the Sunnybrook. Didn't know of them until JJ. Was told by my wife after looking at the WW that if we wanted to continue camping, That (the WW) was the only thing she was going to do it in! http://www.dieselplace.com/forum/images/smilies/eek.gif

RF and tech,

Tech, what rear end ratio does your rig have? RF, what average speed are your mileage numbers from? Would also like to know what RPM numbers your both at. It seems to me, that the taller rear ends get better mileage by allowing the engine to rev a little more while towing. I've noticed this once when I took it up to 70 that the DIC was showing better MPG numbers.

TT,
I have 5:13's on the diff. My average numbers are average speeed of 70. RPM's at 70 are about 2600.

:offtopic: Thursday I got caught in a 25-40 mph headwind pulling the WW. I have not fueled up yet, but the 75 gallon tank is sitting at 1/2. That would put the mileage about 5 mpg or so.

TechProf

The GCW of any 4500/5500 is 26k (limited by the allison)



Subtract your truck weight (including you and you stuff) from 26 and you have your max tow weight. The 4500/5500s do not have any limitations based on cabs or gearing.

My 5500 152" wheelbase single cab, steel flatbed, no power anything 4x4 is probably the lightest 4x4 you are going to see.. it weighs 10,400 with me in it. SO my tow rating technically is 15,600lbs.

I took my factory gcw/gvw tag off the door as I had completed vehicle tag that was placed by the upfitter who installed the bed. As long as I don't exceed axle weights I have had no trouble at the scales.

Howard

Howard, Is this limitation based off of clutch slippage within the Allison or physical strength limits of the case or ? Just curious.:)
Chuck

I dunno... probably more likely just some bean counter?????

The Allisons in the 4500/5500s have some mods done (I have no clue what) if you order 4x4 or the pto option and the model number becomes the 1000 Rugged Duty Series. BUT that doesn't change any of its ratings either...


Seems to me the 4500/5500 could tow a bit more.

Twister,

Lots of Q's and statements there....But here we go:

The limiting factor in tire sizes on 19.5" rims is .... you can't get much larger dia. tires from anyone to fit the factory rims. This is from the Michelin site, but G-Y, Bridge/Firestone, etc. all have just about the same selections. These are what I've ordered from factory:


Michelin

Size/Tread/Load Range/Overall Dia./Width/Rotations per mile/Max speed/ Max Loads (lbs/psi) Single/Double/Tire Wt.
STEERS

225/70R19.5/XRV/F/32 in./8.7 in./648 RPM/85 Mph/3640 lbs. @ 95 Psi./3415 lbs. @ 95 Psi./56 lbs.

DRIVES

225/70R19.5/XDE M/S/F/32.6 in./8.7 in./639 RPM/85 Mph/3640 lbs. 95 Psi./3415 lbs. @ 95 Psi./65 lbs.

I suppose you could contact one of those custom wheel makers to C&C cut you some aluminium rims that are wider, or 22.5" to fit the bolt pattern, which would increase your choices (4X4 types can get "super singles" in 22.5").

Next Q. The 4:44 and ZF 6-speed has worked out real well for 65 mph highway hauling. I just don't race in the same circles as the other fellas, and as a creature of trucker habits, keep the rpms in the high torque range (1800-2300 Rpm), rather than rely on HP peak. This takes longer to get to speed, but does not waste as much fuel. My motto is "let them honk, curse, and one finger salute all they want, as long as they go around". If they were paying my fuel and maintenance bills, they would be cheering for me instead of being rude. If they get too rude, well....that's a good time to test the exhaust brake in 4th :muahaha: .

As far as the F**D exceeding anything over the GM class 4/5, well that is your opinion. I've tried them all (Ford, Freightliner, International, etc.), and the F450/550 test drive was very unpleasant (Mrs. RF's look told me volumes). The turning radius on the Fords are very dissapointing, almost twice that of a 5500. This is not only due to the difference in wheel cut, but also the GM's cab forward design (you are 1/2 way over the engine) which makes for better view forward (13 foot). Another selling point was the straigt rail/ladder type frame construction. I am not criticizing your opinion, just relaying the results of my investigation and my (:rolleyes:) conclusions.

I've got a former die-hard Dodge uncle that has gone through 2 D/C 3500 duallies buy-backs for broken frames (00 and 02) behind the cab, and now cannot stop complaining about his Ford V-10 Gasser (04). Meanwhile, I've not had any mechanical problems in 120K+ miles, and find that the versatility I get for towing/hauling greatly outweigh any inconveniences that comes with the oversize vehicle.

The 26,000lbs limit is a selling point for the MDT makers. Commercial buyers are looking to skim off costs at every corner, and a vehicle that does not require CDLs for their drivers to operate is a big, BIG, saving (annual physicals, insurance rates, higher wages, etc.). So the few of us that use these things for other than route delivery or airport bus service don't influence the big automaker. Physically, the same components are used in the FORD and GM drivetrains. My commercial dealer advised us of the 26,000 lbs. GCWR, but also brought up that the 5500 shares much of its parts/peices-parts with the 6500 lo-pro cab & chassis, which have GC of 32,500 lbs. Weakest links are the Allison 1000/2200 (2400 in 6500), and the clutch/DMF on the ZFs. The DMAX has the capacity to develop more power than these components can handle, and the rest of the drivetrain, well, they have been around for over 50 years, and see much more rugged service than these trucks will ever see, when used in other applications. In our discussions, we were able to find the right combination of parts that would not compromise reliability or warranties, even up to 30,000 lbs. of GCWR. He just could not "recommend" it. Essentially, we spec'ed a C6500 Lo-Pro on a C5500 chassis. Something to look at...think it, but don't say it "out-loud", and the commercial dealer will understand what you are looking for. Bending the bell-curve a bit on one of these trucks is far different than with a light-duty pick-up truck, which is done all the time, if you know what I mean ;).


RF

RF, Thanks for the info. Now it makes sense why the 26k limit. Didn't know about the CDL thing. Insight from someone that has driven for a living is always welcomed! My experiences are strictly RV based. And while I believe I've towed my fair share for RV's, I'd be ignorant to think it compares.

P.S., don't tell JJ about all this research I'm doing. My 'AAAA' membership would have to be upgraded! ):h

Mum's the word. We'll keep it amongs us GMC'ers.

RF

:coolio: :stick_out :naughty: