I've got an 01 Suburban 1500 with the 5.3 now, and while it does a good job of towing I'm looking to replace it with a crew cab 2500HD.
Most of my towing is within 5 hours of me, with maybe once a year taking a 2000 mile round trip. I might tow maybe once a month. I tow my 79 FJ40 on a 16ft trailer.
I'd like the Duramax, but it's a $4800 option. The 8.1 is only $800 over the 6.0.
If the 6.0 is enough, I'd probably rather have it for the fuel mileage as this will be my daily driver. If it doesn't have the guts to hold 70 or so on grades, then I'll look into the 8.1. I don't want to spend the money on a new rig and then be unhappy with the performance. I don't drive far to work, so fuel mileage is not a huge concern, but I do have to take it into account.

Or maybe I should just shut up and get the Diesel!
:D

I have the 6.0, and the 8.1 is only an $800 option IF you stick with the standard tranny. If you go auto, add another $1,200 for the Allison since the 6.0 gets the 4L80E.

I'm towing a 1980 Toy longbed with a SBC/TH350 & Q78 TSL's on a 16' tandem-axle trailer. With 4.10's & 245/75 tires, hitting a hill at 75, it'll drop to 65, downshift to 3rd, and then hold 65 or accelerate back to 75 - depending on steepness of hill - w/o pushing it too hard (3,400 R's).

Runnin' empty around town, I get about 13 MPG (X-cab/Shortbed 4wd 2500HD). Towing, 9-11 depending on speed. Empty on the Interstate ~15.

My assessment? I have the ideal truck for my trailer weight. If I were towing continuously in the mountains or hauling a significantly heavier trailer, I probably would have opted for the 8.1 or Duramax. As is, I think I made the right call.


TEX

Thanks Tex. I'm trying to stay realistic with my purchase. All of my buddies use Cummins rigs to tow with, and I want to be able to keep up somewhat. They were waiting for me a few times in the hills on the way to Moab this year.
You brought up a good point too that I hadn't thought about. All the 2500's I saw on the dealer lot had 3.73's and you mentioned you have 4.10's. The 6.0 and the 4.10's would be a good combo, as you may give up a little on unloaded MPG, but get better performance towing and have a lower purchase cost than the 8.1.
A friend of mine has the 8.1 in a 3500 crew cab dually and he gets 11mpg on his commute to work. 13-15 sounds better to me.

Originally posted by JasonH
All the 2500's I saw on the dealer lot had 3.73's and you mentioned you have 4.10's. The 6.0 and the 4.10's would be a good combo, as you may give up a little on unloaded MPG, but get better performance towing and have a lower purchase cost than the 8.1.


The 2500's have 3.73's or 4.10's optional. 4.10's are the ONLY ratio available for the 6.0 2500HD's though. Truth be told, I wish I had 4.56's. The 4.10's are PERFECT for the stock-size tire when towing, though 3.73's would work great runnin' empty. But, I'd like to upgrade to 255/85's which are about 8% larger than stock. And 4.56's are about 11% lower than 4.10's, so that'd be REAL close to the same gearing I have now.



TEX

We have an 01 GMC hd2500 ext.cab long bed 4wd 8.1 w/allison at work.We pull a john deere 5300 4wd tractor/loader with it.

Not sure how much it weighs,maybe 4,500-5,000lbs and the trailer 1,500-2000lbs.

It pulls it around with no problem,except for rear tires wearing out to fast :D

get the truck with the 8.1 and allison trans. , just make sure you get 3.73 gears and locking diff. , You'll be fine...

i have several friends that drive the new chevy's,some with the 6.0 and some with the 8.1,and they all love there trucks.it seems to me the only bitch with the 8.1 is the 10mpg,but they claim they pull great.i have 2 friends with the 6.0,one with a standard and the other with the auto.the one with the auto has about 2500lbs of tools all the time,he says if he hooks to a trailer with all the tools it gets slow but does the job.he has 150k on it,but did have to change a tranny because of the crappy plastic line on the cooler that came loose and dumped all the fluid.

i think anyone will do just fine,but the 6.0 will get a little better milage.but then what do i know i have a ford:D

I have talked to people in comparing the 6.0 vs. 8.1. Heres what I gather ----- Of course the 8.1 gets better tow ratings and less gas mileage...... BUT... Theres only 3 mpg difference in hi-way driving unloaded, and the same towing. Hows that ?

I would recommend the Allison tranny, I don't think the 6.0 comes with it though. I did not like the gear jump between 3 and OD on the 5.3l auto tranny, it was to big.

Karl

Originally posted by KMAN
I would recommend the Allison tranny, I don't think the 6.0 comes with it though. I did not like the gear jump between 3 and OD on the 5.3l auto tranny, it was to big.

Karl

No, the 6.0 does not come with the Allison, it comes with the 4L80E. Your 5.3 has a 4L60E. FWIW, the jump from 3rd to 4th is from 1:1 to .69:1 in your tranny. In the Allison, the jump from 4th to 5th is 1:1 to .71:1. In the 4L80E the 3-4 jump is 1:1 to .75:1.

TEX

Jason,

I hear ya! I have the 2500HD Crew Cab shortbox 6.0 gas automatic. Only gearing is the 4.10 with the 6.0. It is a 2WD version. Yes, locking diff. Camping down at "birfield barn" and getting back up the road at Gilmer was a bit interesting... empty tow dolly. Wouldn't want to pull the FJ40 up that road!

Price was right, LS had the right options.

About 10K miles on it. The FJ40 sits up in the air stream, need to flip the windshield down... still about 11 mpg towing @ 70 mph. Hilly stuff, keeping my foot on it, dropped to 10 mpg for a short section, but avearaged around 11 mpg for the trip.

Open freeway @ 75mph, I get around 15 mpg. Around town is about 12 - 13. Overall pretty happy with it. From talking with other folks with the 6.0 Crew cab, the 4x4 option will drop the mileage numbers about 1mpg.

Highway average: 11mpg towing, 15 mpg empty
(just about the same as my FJ40!)

Tom Walter

I have a 2001 3500 4x4 extended cab with the 8.1/Ally/4.10 combo. I get about 9 mpg around town with spirited driving. About 11 or 12 mpg on the highway running 75-80 unladen. About 6-7 pulling a 16 foot utility trailer with a 4500 lbs trail rig at about 70 mph. And finally about 5-6 mpg pulling a 32' gooseneck with two 4500 lbs trail rigs at about 70 mph.

The truck is stock except for some 235/85/16 tires (which are taller than the 215/85's that came stock). Which may explain some of the poor mpg I am seeing. Also have a 50 gallon reserve tank in the bed which makes life on the highway much easier (I am no longer the first truck that has to pit stop). With 80 plus gallons I am good to go for at least 500 miles between stops. Although a complete fill up is way past $100.

The 8.1/Ally combo pulls all of the above very well. Lots of power unladen (essentially infinite passing power). Still has lots of passing power pulling the utility trailer and one trailer queen. With the gooseneck and two trailer queens, passing becomes more of a chore and is not really an option going up hill.

Blister

I have the 8.1 with the Alllison trany and 4.10 gears with 35's on it. It has no problem towing a 7000 lb trailer. But I still wish I had done the diesel.

if money is tight get the 6.0 i own a lawncare company and run a 6.0 hd 4x4 tow a 20 foot landscape trailer and load the shit out of the truck all the time....usually i am towing 2 commercial riders with a few push mowers and some trimmers and back pack blowers....i have towed my old tj with the truck fairly pakced over 1000 miles round trip on weekends and didnt even notice the jeep was back there...it towed awesome....my buddy used to tow a 30 ft enclosed trailer with his with my tj 2 three wheelers and 3 dirtbikes in the trailer no problems either...i think the 6.0's are good ..also both trucks had 4.10's with limited slips and 305/70 mtr's...did pretty good on some of the bigger hills in michigan but i cant comment on the rockies or anything like that

I was in your same situation a few months ago. I was pondering 6.0 or 6.6. My 99 1/2 was on the rack with the tranny out of it and far from home and no hope of having it fixed this year, so I traded it in. The guy who fixes the trucks said to get the 6.0 with the 4L80E and not the Allison. He said the Allison is having too many heat releated problems and it does not do well with stop and go driving. I now have 2002 4X4 2500HD with the 6.0 and it does a great job, just it is not as fast as the 1/2 with the 5.3.