Towing 10k - turbo, supercharger, or big block? MPG & other issues...

[Tharber]

The reason many guys use a 5.3 and turbo is because you can turn up the boost on the smaller engine. For your use, I'd say a 6.2 with a turbo could last forever with no issues. If you don't want to go that route, a Magnuson SC will get better fuel mileage than say a Whipple but thewy will loose efficiency with heat so a good intercooler system is a must. I like the SC route myself because it's almost a bolt on. a SC will need very little maintenance other than changing the oil.

 

[CKN]

First and foremost is worry about being able to make it STOP. Trailer brakes are a must. Power is not a problem with any recent vehicle.

I have hauled 12k with a 2011 Silverado Z71 5.3 6l80 all stock and it would still chirp the tires if you hit it hard. That was with the load properly on the trailer without overloading the tongue.

Good luck finding a Suburban that isn't rotted out for a reasonable price regardless of year. A 3/4 ton is a unicorn anymore and go for more than new if it has less than 100k on it.

My 3/4 ton suburban with the tbi 350 will pull a mountain and get going reasonably fast if you don't care about being first to the next stop light.

I have owned three of these trucks...towing. What planet where you on when you chirped the tires towing 12,000 pounds?

 

[spasm3]

Factory 3/4 ton truck , gas engine fits the bill. Modifying a 1/2 won't be as reliable, and you won't have as stout of a trans, rear end, or brakes.

 

[bullwinkle]

At least a 3/4 ton, preferably a 1 ton (IMO mainly for the full floater rear axle), 6.0 or 6.2 GM, 4L80E or 6L80E transmission, as low a gear ratio as you can get. Trailer brake controller, weight distributing/Class V hitch (or gooseneck in a pickup), new enough to have 4 wheel disc brakes. My Express 3500 hits most of those notes (although I still need to get my brake controller in it), but it would be better with 4.10 or higher posi rear full floating axle (gone by 2011, unfortunately), it only has 3.73s. DPF diesels & Hemis are NOT the way to go, and my company has blown up several 3.5EB F-150s. Be prepared to buy gas, though! Half tons are really not made to work, they don't tend to have the drivetrains or suspensions to handle it (as do many light duty 3/4s, like our cursed Transit 250s).

 

[jhellwig]

I have owned three of these trucks...towing. What planet where you on when you chirped the tires towing 12,000 pounds?

It surprised me also but it happened. 500lbs on the tongue of a trailer doesn’t put much more load that normal on the rear end of a truck. If I got closer to being on the bump stops when I loaded it it wouldn’t do it.

I wouldn’t want to do it every day because that much weight on an equipment trailer pushes a 1/2 ton around but it is fine on occasion. Power isn’t the issue.

 

[UncleDave]

For constant 10K towing a 3/4 truck is the answer.

If you are going to mod your 5.3 I'd put a big bore stroke kit and some top end mods.
Up the trans cooler, oil cooler and radiator and you are done.
Better yet build that separately (5.3's are cheap) and put your stock rig on a stand.

Once you move to the air pushing stuff turbos and blowers you are dealing with radically altered spark and fuel delivery, much more sensitive fuel needs and stressing the parts as much or more than a bore stroker combo anyway. I never had any luck bolting this stuff onto stockers myself and needed to go into the short block to make them live anyway.

5.3L 383 Stroker Engine Build - Displacement & Replacement

In part one of Torque Tech, we subjected our 5.3L test engine to a few much-needed bolt-on performance parts. Adding a set of GenX 205 heads and matching cam fr

www.motortrend.com

 

[D60]

I realize the thread's been dormant for a couple days and there's so many opinions here mine will hardly be heard, but that's ok......

Any 2011+ F250/350 in gas is a strong choice. The 6.2 is very respectable as gas towing engines go and reliability tends to be exceptional. The 6R140 is an awesome trans for towing with tons of driver control.

In the right chassis you get the big 35 gallon tank so, yeah, you're gonna drink gas but at least you can carry a lot of it. 4.30 gears were optional (what I have and a must in Colo).

I saw mention of FF vs SF rear end but basically every SuperDuty is gonna be a full floater.

There's the famous Flat Bed Ed who put ~440k on a 6.2 in hot shot service before needing a new engine.

I towed thru CO in my old '03 2500 Burb with 8.1. It was miserable. Wheelbase is way to short so have a wd hitch to help keep the steering wheels planted. The 4L85 never had the right gear with 4.10s. It wanted to hold second just to cruise through the San Luis Valley (flat, and plenty of UFO sightings and cattle mutilations!) in CO at highway speeds at 4500 rpm. 3rd was not enough or at least it didn't think it was and it wouldn't hold 3rd.

Also if you get a 2500 Burb in the 800 platform watch that dual tank/dual pump setup. It can be a real feces show.

 

[GON]

Going to compose offline because so many quick responses, i'll try to compact my followup.

SubieRubyRoo mentions great mileage with an ecoboost, this is why i'm curious about turbos, I just didn't see MPG figures suggesting better than the v8 for unladen - modern v8's will get 17-23 on the highway with good aero. It COULD be different with a load and that's why i'm interested - also altitude compensation is really nice. That alone has me posting things because a big block thru the rockies runs out of steam as you climb more than you think.

racer12306 - i dont think it's too extreme either, i'd just like a 30-40% torque boost to make pulling easier.

To several - i'm not planning on overworking a smaller vehicle, quite the contrary. Considering getting a big block Suburban and downswapping to a 5.3L in a search to reduce total fuel cost over the next ~200,000 miles or more of life since this will spend alot of it's time unladen or lightly laden. I would think that would pay for itself in gas over keeping the big block.

Part of it is people say a 6.0L LS is fine but a 5.3L LS is not. ITS BASICALLY THE SAME. The 6.0 doesn't have stronger pistons or rods or crank than the 5.3 or even 4.8 yet you can buy a 6.0 in the HD 1500 series doing what i'm doing and people with the HD chassis trucks are towing like 90% of the time i'm told whereas i'm talking about WEEKEND TOWS not all day every day here, don't get your panties in a twirl. This isn't 100,000 miles of use with 10k behind it the whole time - this is 100,000 miles of use with weekend trailers of varying weight, usually out empty, back with something including to grab project cars for people but even then i'm not grabbing 52 cars per year either. Most of it's use is unladen - I just want some more torque when there IS something back there.
The only thing I see a disagreement on is what is producing the downward torque on the pistons and is light forced induction easier on an engine than pushing wild cam profiles and higher RPM to get the power up? Is 4000rpm in 2nd better than 3000rpm in 3rd with 4psi up a hill? LS's are already called overengineered and Ecoboosts are already doing it with a V6, is that overworked? I think there's alot of misunderstanding here.

I have grabbed a lot of "project cars", with my 1-ton F350 with the 3v 5.4L, standard cab. I think the center of gravity is a safe towing vehicle, which means a 3/4-1 ton truck. If you want to drive the rig aggressively, or even assertively, a 7.3L gasser or a diesel is likely a great match. If you are not in a rush and safety is key, most 3/4 ton trucks stock will do just fine with an open car hauler and a 4500 lbs. vehicle on the trailer.

Here is a pic of my 1 ton 5.4l picking up a S-class from an auto auction, towed about 300 miles. I have used the same truck to haul vehicles from coast to coast. No race car by any means- but safe. And for note, 8MPG (ouch).

 

[Fabulous50s]

The 6R140 is arguably the best auto for towing. GM and Ford both use the the transmission which was designed by ZF and manufactured by Ford under license. But for wherever reason GM 6 speeds don't hold up as well. I think it's due to Ford always using a heavier rating and axle than a comparable GM. Such as Ford uses similar drive train in a 3/4 ton as GM uses in a 1 ton and so on.

 

[mattd]

I think you mean the 6R140. And yes, they are a great transmission. I love it. They are easy to rebuild too if needed.

 

[D60]

For me 6R140 was a game changer because it's exactly what an auto should have been from the start.

A lot of people talk about manual mode for towing and that can be nice for just putting in a given gear and leaving it there. Just like a manual it won't try to downshift even if you jam the pedal to the wood, and it won't downshift to try to help slow you no matter how hard you stab the brakes.

But equally impressive is the ability to leave it as an auto and simply drop out gears. Want your 6 speed to be a 3 speed? No problem just delete 6, 5 and 4. Great for urban situations or low speed driving (road construction anyone?) where you don't want 6th at 35mph

All laid out on a simple clear display: 6 5 4 3 2 1. No dropping the lever or limited selections like 2 and 3 but no other choices.

I'm sure the newer transmissions like the 10sp are even better but for me the 6R140 was the first "driver's" automatic in a tow rig that gives you absolute control at all times with super easy user interface.

Furthermore, people tend to overlook the importance of a good transmission for towing, particularly with a gasser where torque is less abundant. An average power plant with a great trans is often better than a powerhouse with a lackluster transmission. For me the GM 8.1 sucked for towing but the poor engine was strangled by limited options from a 4sp auto, and in stock form I was unable to force it to just stay in 3rd no matter what -- if I tipped into the accelerator it'd go for second.

 

[Nick1994]

I think first you need to come up with the budget. You're talking about 383 Chevy engines but at the same time you want to keep it for 20 years. Anything you can put a 383 in is already 25 years old, you're wanting something to keep to be upwards of 45 years old?

Buy once and cry once, find something stock, maybe truck prices will come back down to Earth in the next year or two and pick up something pretty new like the Ford 7.3L.

 

[wlk]

You can boost an engine in a 1/2ton all you want but if the tow rating isn't there, you are wasting money. Find any 3/4 + ton van, Suburban, Excursion or truck and it will be the best way to go. 2wd will get you a smidge more towing capacity, mpgs and less things to go wrong. My buddy at work had a 3/4 Suburban and had zero issues towing a larger camper. Good luck with the search.

 

[Cujet]

Just a quick thought about towing and engine efficiency. BSFC of modern engines is well understood. When a certain amount of heavy work has to be done, it takes a very specific amount of HP. Despite wild claims of fantastic MPG, most modern gasoline engines will achieve about the same towing MPG when accurately compared to each other.

Making 100HP will consume about 8 gallons per hour, plus or minus a bit. The BSFC of a loaded gasoline engine is about 0.48 pounds of fuel per HP per hour. Yes, some modern heavy duty gasoline engines can achieve 0.42 LB HP hr, but that is typically under light loads, where timing advance, the advantages of high compression, direct injection and more can come into play.

The Ford Ecoboost engines eek out a bit better BSFC numbers under some conditions, as they have fewer moving parts and operate at higher outputs at lower RPM, for lower frictional losses. But when you ask them to pull a 10,000 pound trailer up a steep hill, they use every bit as much fuel as the competition.

Yes, your old, low compression, carburetor equipped "Big Block" is worse in this regard.

To get significantly lower BSFC numbers, a diesel engine is required.

 

[wpod]

I may be in minority here, but a Chevy 4.8L V8 with a properly sized turbo seems like a winner to me, as far as your requirements go...

An ecoboost engine life with proper maintenance and luck of the draw usually exceed 200,000 miles.

 

[supton]

I'll buck the trend and say, get a big block. And a commuter. A 3/4 or 1T for daily driving will be rough, a 1/2T will ride more comfortable, until you routinely pull 10k with it. A 3/4T that is relatively new and capable will be... pricey. At what point is the $$$ out of pocket the same for two older "lesser" vehicles, each optimized for the duty at hand?

When it's snowing, do you need to tow? I wonder if you could get a "less desirable" 3/4T / 1T 2WD for less money, and then have a bit of coin for a decent 1/2T for daily driving (or SUV, or whatever, it could have much more modest towing for when needs are lighter).

 

[dumkid]

my parents had a 6.0 suburban, 2500 4x4, got 14mpg unloaded and could pull 8000 lbs just fine. my dad has a 2003 ram with a Cummins and a manual transmission and it gets 20 mpg unloaded and isn't bogged down as much while towing as the suburban. turbos and reliability don't really go together, at least on gas cars.

 

[AdmiralYoda]

I may have missed this...but what year suburban is this potential engine going into? It gets messy swapping in newer engines into older but "modern-ish" vehicles. You need to stick with the engines compatible with the ECM in the vehicle, sort of. For example it would be difficult to swap a 2017 Ecotec3 5.3L into a 2000-2006 Suburban. The Suburbans ECM won't play nice with the newer engine and the 2017 ECM won't place nice with the 2000-2006 Suburban's PCM, BCM, TCM etc.

That said, unless it is an older square body I'd stick with the engines that were available for whatever generation of Suburban you have.

To do this right it isn't cheap. And MPG shouldn't be your top concern. Durability and reliability should be number one, followed by capability.

And sometimes you get better MPG while towing with a larger engine because it isn't being worked as hard.

That said, there is no replacement for displacement. If this is a 2000-2006 Suburban I'd go with a 6.0L. A cam is a good upgrade for durability and low end torque! For the 2007+ Suburban get one with a 6L80/90 transmission. The gear spread helps significantly.

Make sure to go with a 3/4 ton. You'll need those brakes, suspension and cooling.

If this is a Square-body dream build... get a 2009+ 6.0L and 6L90 pullout with the ECM and harnesses. Another option is Holley's Terminator X Max EFI computer. Depending on the model it can control any Gen3/4/5 engine....and a 4L80 transmission as a standalone setup. It is self learning and self tuning.

Differential gearing will be your friend. Pick some gears that will put you around 2000RPM in overdrive.

Good torque upgrades would be a BTR Racing Truck Norris cam and a Trailblazer SS intake manifold. Maybe a slightly larger throttle body too. Long tube headers and a free flowing exhaust will also help.

 

[cb_13]

Upgrade to a crew cab Superduty with a 6.2. You’re gonna be stressing that suburban greatly if it’s a 1500.

The Superduty chassis is excellent and depending on year/options will have the 6r140 or 10r140 both of which have proven to be reliable. The 6.2 has also shown to be reliable, can expect an unloaded mileage of about 14 and 405-430 ft-lbs of tq depending on year. 4.30 gears will help with towing power. Expect about 8 mpg when towing heavy.

A coworker went from a 6.2 to 7.3 gas both in duallys that he mostly used to haul cattle or round bales. He said the 7.3 gets significantly better mpg when towing heavy than the 6.2 truck did. He also went from 6 to 10 speed trans. The 7.3 trucks will cost you a pretty penny though.

 

[homeyclaus]

Towing mileage will be comparable between all platforms. Why? Because getting the weight moving, and keeping it moving, is going to be close to the same. If what you're towing, aerodynamics of the trailer are going to dictate what it takes to keep it moving through the air you're pulling it through.

Engine efficiency doesn't vary all that much anymore either. Diesels will be at one rate, and gasoline engines at another. Yes gearing matters, yes all engines have an rpm sweet spot, but unless you're the jerk on the highway you're not likely to be in it often anyways.

The mpg variance you will find is with an unladen vehicle. I work through a spreadsheet with mileage numbers I gather, and for me pulling my 8400 lb camper and family, next will be a hybrid F-150 based on my towing miles, unladen miles, and desire for torque. I have no illusions - it'll burn fuel at the same rate as the truck it replaces when towing: 7.5-9.5 mpg. Strangely, my towing pattern works against diesel - I'd need to tow less to end up with a similar total cost of ownership.

As others have said - _stopping_ is going to be the determining factor with any load you tow. A VW Golf will eventually get 10k lbs moving, and keep it moving in most circumstances. It won't have a snowflake's chance in hell of stopping it in a reasonable distance, or steer it around something that needs to be steered around right now.