Chevrolet / GMC 6.0L Engine?

[nvestysly]

I'm considering our next (probably used) tow vehicle and will likely stay in the ranks of Chevrolet / GMC gasoline engine. In particular, the 6.0L.

Yes, I know there are lots of reasons to go with diesel and to consider other brands of tow vehicles but for this thread I'd like to stay on the topic of the 6.0L engine commonly available in 2010 (or so) model trucks and SUVs.

I currently tow with a 1996 GMC Suburban 7.4L and a 2005 Chevrolet Suburban 8.1L. Those engines are rated at 290 HP @ 4000 RPM / 410 LB-FT @ 3200 RPM and 320 HP @ 4200 RPM and 440 LB-FT @ 4200 RPM respectively. The 8.1L has noticeably more power than the 7.4L but it also has fewer miles on the engine. Both vehicles have a 4-speed automatic. I think these are great tow vehicles in large part due to the gobs of torque created by the big block engines. The transmissions downshift when going up a steep/long hills so the engine revs but I very seldom lose speed or have to limp up a hill at 45 MPH.

I may be off a little on the engine ratings but the numbers are in the right ballpark.

The later model trucks and SUVs with the 6.0L engine use the 6-speed transmission. The 6.0L engine produces 352 HP @ 5400 RPM / 382 LB-FT @ 4200 RPM

So anyone that has knowledge and experience with 6.0L I'd like to hear your comments. Some questions on my mind are...

1) The torque rating on the 6.0L engine concerns me. The 6.0L has 7% to 13% lower torque than my current tow vehicles.

2) Is it reasonable to think the 6-speed transmission will make up for lower torque? I can certainly imagine the 6-speed will have more suitable gear choices when tackling hills.

3) I've seen reference to cast-iron 6.0L engines and aluminum block 6.0L engines. I suspect the vehicles I'm considering - trucks and SUVs - will use the cast-iron but I'm not sure.

4) Later model trucks and SUVs I'm considering come equipped with the 3.73 differential. My current tow vehicles are 4.10 differentials. Any concerns with 3.73? I guess the manufacturer is going for higher MPG.

5) The 6.2L gasoline engine in the recent Denali line looks very comparable to the old 7.4L and 8.1L specifications. Is it worth holding out for a good, used vehicle with the 6.2L engine?

[overlander63]

I used to tow our 31 all over the country with a 6.0 Chevrolet. It had the 3.73 gears, and if you can find one with 4.10, it would be much better. I regularly towed our 7700 pound trailer over Cajon Pass in California at the speed limit for trailers, which is 55mph.

[field & stream]

Hi -- I towed a 23" Safari (actual weight loaded about 5,000 pounds) with a 2001 Denali with the 6.0 motor, 3.73 gears, and a four speed transmission. First tow was from Colorado, across Wyoming on 80, and down 15 to California.

For your reference, I disclose I am a higher-performance guy who does not begin to understand those who take pride in how little tow vehicle they can make work. Here are a few of my answers to your questions:

> Yes, the 6-speed transmission will make up for quite a bit of torque and horsepower difference
> The cast iron block was used in trucks and SUV's, the aluminum block was used in cars. Many hot rodders prefer the cast iron for the added strength.
> The 6.2 is a great motor too, and has more hp and torque.

In terms of advice I would certainly need to know the weight of your TT, and where you plan on going (e.g. the Rocky's vs. flatland). The other variable which only you can judge is how much performance is adequate for you?

For me: I supercharged the 6.0 and it now has about 500 hp and 500 torque. What hill?

[Tincampers]

We towed with a 6.0l and 4 speed transmission. 75% of the time it was fine. Add in any kind of incline and performance suffered. Add to that 9 mpg and I was ready for something better. We had the 4.10 gearing.

[Tuco]

Originally Posted by field & stream

Hi -- I towed a 23" Safari (actual weight loaded about 5,000 pounds) with a 2001 Denali with the 6.0 motor, 3.73 gears, and a four speed transmission. First tow was from Colorado, across Wyoming on 80, and down 15 to California.

For your reference, I disclose I am a higher-performance guy who does not begin to understand those who take pride in how little tow vehicle they can make work. Here are a few of my answers to your questions:

> Yes, the 6-speed transmission will make up for quite a bit of torque and horsepower difference
> The cast iron block was used in trucks and SUV's, the aluminum block was used in cars. Many hot rodders prefer the cast iron for the added strength.
> The 6.2 is a great motor too, and has more hp and torque.

In terms of advice I would certainly need to know the weight of your TT, and where you plan on going (e.g. the Rocky's vs. flatland). The other variable which only you can judge is how much performance is adequate for you?

For me: I supercharged the 6.0 and it now has about 500 hp and 500 torque. What hill?

So your THAT guy on the 154...

[field & stream]

Originally Posted by Tuco

So your THAT guy on the 154...

Hi Ojai -- you mean that flat road between Santa Ynez and Santa Barbara?

[Tuco]

Yea, that flat stretch of road where the beast is flat out in 4th gear and 48 mph for the final climb to the top on the way to Rancho Oso off Paradise Rd. Need to get to the Longhorn Cafe for a good breakfast soon.

[nvestysly]

Originally Posted by field & stream

Hi -- I towed a 23" Safari (actual weight loaded about 5,000 pounds) with a 2001 Denali with the 6.0 motor, 3.73 gears, and a four speed transmission. First tow was from Colorado, across Wyoming on 80, and down 15 to California.

For your reference, I disclose I am a higher-performance guy who does not begin to understand those who take pride in how little tow vehicle they can make work. Here are a few of my answers to your questions:

> Yes, the 6-speed transmission will make up for quite a bit of torque and horsepower difference
> The cast iron block was used in trucks and SUV's, the aluminum block was used in cars. Many hot rodders prefer the cast iron for the added strength.
> The 6.2 is a great motor too, and has more hp and torque.

In terms of advice I would certainly need to know the weight of your TT, and where you plan on going (e.g. the Rocky's vs. flatland). The other variable which only you can judge is how much performance is adequate for you?

For me: I supercharged the 6.0 and it now has about 500 hp and 500 torque. What hill?

The owner's manual for our 1992, 29ft. Classic indicates 5600 pound dry weight. We have lots of stuff and normally travel with nearly full 60 gallon fresh water tank for boondocking. I haven't taken time to weigh the rig as loaded but plan to do that soon. I imagine we're near 7000 pounds loaded.

As far as where we travel or plan to travel - everywhere. I certainly don't want to be limited by our engine and drivetrain.

I recently looked at a few web sites regarding supercharging. Tell me more about your setup - brand, ease of installation (I'm a DIY person when feasible), approximate cost, etc.

Thanks to everyone for your comments. Keep them coming.

[vintageracer]

If you are considering a USED gas motor truck and can handle 10-11 MPG ALL THE TIME loaded or unloaded look at a 2500 or 3500 Chevrolet/GMC truck equipped with the 8.1 liter engine and the Allison Automatic Transmission. Pulls like a diesel all the weight you want.

IF you can find one of the VERY RARE but out there and desirable 8.1 litre trucks equipped with the 6 speed MANUAL transmission you will get 11 MPG all the time.

REPEAT 10 MPG loaded or unloaded for the Allison automatic transmission truck and 11 MPG for the manual transmission 6 speed truck.

I have pulled many a mile in a 8.1 litre Allison Automatic Transmission equipped 2500 series 4WD Crew Cab Short Bed Single Rear Wheel Chevrolet PU with a 2 car tag trailer LOADED (10k-12k Lbs) running 80 MPH.

60 MPH or 80 MPH LOADED OR EMPTY the truck STILL got 10 MPG no matter how you drive it!

IF you can stand the fuel mileage you will have "NO WORRIES MATE" pulling your Airstream trailer or much of anything else for that matter!

[J. Morgan]

The 6.0 L truck with 3.73 gears will out pull your 454, and do so more efficiently.

My point of reference in making the declaratory statement is that my 5.3 L 3.73 truck will out pull any factory stock 454 made since 1978. I say this bluntly without equivocation.


Brevi tempore!

[field & stream]

Lucius - There are a couple of ways to go here.

The turnkey approach is to get a Callaway-modified pickup or Suburban from a Chevy dealer. Not cheap but quick, easy and full warranty from GM.
LINK: Callaway Silverado/Callaway Sierra

The way I went was to buy a complete supercharger/intercooler kit from Magnuson in Ventura CA. Because this project is over my head, I had a local hot rod shop (Bel Air Ranch) do the build starting with a new 6.0 long block from GM, which honors the warranty with the blower installed. Total cost, including complete tranny rebuild with HD parts, about $16K. Not cheap, but way cheaper than buying a new vehicle!
LINK: Magnuson Products, LLC

We have over 25,000 miles on this motor, the majority of which have been with one or another trailer attached. Zero problems. (Maybe because it is only about 6 pounds of boost, and maybe because we see it as a tow vehicle and not a race car and drive it conservatively.) No regrets, and would absolutely do it again.

Gas mileage is the same as without the blower. As the Magnuson guy told me, the only part of this system that can cause more fuel to be used is your right foot!

[A W Warn]

After towing for many years with a half ton, I bought a brand new 2010 Silverado 2500 with the 6.0L. That is the only Chevy vehicle that I owned which disappointed me. The first time I went to the mountains I knew I made a mistake. Towing my 25' at ~6,000 lbs it struggled in the mountains going uphill. It did not have enough power. The problem is the 2500 is it is a much heavier truck than a 1500. The truck is towing that additional weight with basically the same engine as a half ton. I'm not sure of the exact weight difference, but it is substantial. To boot, my 6.0L was a gas hog, whether empty or towing.

I've had both the 5.3L and the 6.2L in half ton truck. No doubt the 6.2L is a more powerful engine, but the truck I own now has the 5.3L & 8 speed with the max tow package. I'm happy with it!

If I were going to buy a new truck today, I would get a half ton, maybe with the 6.2L.

My advice: If you can keep payload low enough, go with a half ton. If you need to haul more stuff, go with the three quarter ton.

[lahrfarm]

I currently own a 2015 2500 6.0 six speed. I tow a 31' excella, and many other trailers. The 6.0 is not a diesel, but I can't tell my airstream is back there. It has no trouble, even with incline. Diesel is no doubt the best, if you tow often enough to justify the cost. If I were a fulltimer, or anytimer I may buy a diesel. I have no complaints about my 6.0 matched to the six speed transmission, for the amount of miles I tow.

[featherbedder]

Originally Posted by field & stream

Hi -- I towed a 23" Safari (actual weight loaded about 5,000 pounds) with a 2001 Denali with the 6.0 motor, 3.73 gears, and a four speed transmission. First tow was from Colorado, across Wyoming on 80, and down 15 to California.

For your reference, I disclose I am a higher-performance guy who does not begin to understand those who take pride in how little tow vehicle they can make work. Here are a few of my answers to your questions:

> Yes, the 6-speed transmission will make up for quite a bit of torque and horsepower difference
> The cast iron block was used in trucks and SUV's, the aluminum block was used in cars. Many hot rodders prefer the cast iron for the added strength.
> The 6.2 is a great motor too, and has more hp and torque.

In terms of advice I would certainly need to know the weight of your TT, and where you plan on going (e.g. the Rocky's vs. flatland). The other variable which only you can judge is how much performance is adequate for you?

For me: I supercharged the 6.0 and it now has about 500 hp and 500 torque. What hill?

I am also high performance person having built many dirt track flat track cycle race engs. and flat track race car engs.Not true that Gm only used aluminum 6.0 eng. in cars, cast iron in trucks & suvs. As 6.0 alu. eng. are used in 2500 pu as standered in 1999 and earlier with 3.73 std. gears. A 4.11 rear will out pull 3.73 but at lower gas mileage. My 6.0 avg. 10 mpg as my 1979 cast iron 454 w. 4.11 is 4 mpg....

[A W Warn]

Originally Posted by A W Warn

snip>>>the truck I own now has the 5.3L & 8 speed <<< snip

Typo in the above post. It is a 6 speed, not 8.

[TomW]

Originally Posted by nvestysly

I'm considering our next (probably used) tow vehicle and will likely stay in the ranks of Chevrolet / GMC gasoline engine. In particular, the 6.0L...

I just LUVS the power my new-to-me's 2013 Silverado's 6-liter has. It's even more awesome than my '99 Silverado was.

The attached image is from our last trip of 2015.



In a word of warning, while the truck itself is awesome too, it is TALL. The image also shows a step I took with me so that my 6' tall frame could get the firewood out of the bed. It's still a keeper, though.

Tom

[nvestysly]

Mostly good things being said about the 6.0L but I remain on the fence. Maybe after I test drive our friends vehicle I'll feel more comfortable. I may ask them if I can tow a trailer down the road a few miles to see if I notice any significant difference relative to our big-block Suburbans.

I like the idea of the supercharger but the Magnuson web site didn't list a kit for a 2010 Suburban. I'll need to call them to verify availability of a kit.

Thanks for all the comments. If you think of anything else please post to this thread.

[gandttimes]

We tow a 2014 25ft with 2008 GMC and 6L( aluminum block )with maxtow. 4.10 gears and absolutely no issues.
You have to remember that these new engines love to rev unlike the old stock big blocks that felt like they were going to self destruct at 3000rpm.


George

[Elbo]

Just for fun and laughs I will add my two cents worth. I have a 05 Dodge that has close to 300,000 miles and it has never had a "tune up" to keep the 19 to 22 M.P.G it gets. I have only changed the oil and fuel filter 10 times in fifteen years.
Oh! did I say its a "Diesel"

[slowmover]

How fast one is going up ascents is irrelevant. A test of nothing. I regularly climb at 32-37/mph.

It is the descent that matters.