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

Oct 6, 2014
Also don't just say "diesel". :) I know that's the REAL right answer but $5.50 a gallon and shortages are giving me pause. They're also difficult winter starters in minnesota...


At the point when I replace my current light duty pickup truck with something 3/4 ton or 1 ton I plan and need to tow 10k behind it on a ball hitch. (mostly to use a car hauler, less aero loads than an RV) I'm willing to swap or modify engines to get what I want because I plan to use it for 20+ years to come. Plan is to get a Suburban with, or swapping to a 5.3L LS.

If i'm keeping it that long i'm thinking about long term fuel cost, ongoing maintenance costs, future replaceability. (availability of future junkyard cores if something dies to swap in cheaply)

I need the ability to tow variable weights (but generally lower aero resistance) on weekends, otherwise it's an all purpose 2nd vehicle at least, daily driver in winter when roads are iffy.

I know a big block will do the job and might be simplest but regular driving of a big block drinks gas, I used to do it and had to get rid of it. I consider a 6.0L LS to almost be a big block/this is as much a question about using more commonly available and cheap engines with a power boost for towing like the 5.3L or even 4.8L.

Option two is doing my own version of fords ecoboost and turboing the 5.3L. Though everyone with an ecoboost tells me they get v8 mileage/I don't know why but I rarely or never hear of a turbo engine getting the same mpg as a nonturbo engine. Saab tried to make one back in the 90's calling it a light pressure turbo using steeper gearing and a higher engine load to put the specific fuel consumption more on the high efficiency island but I don't know how well it succeeded in the real world. At times i've wondered if a rear mount turbo and a physical turbo bypass (similar to exhaust cutouts) would give small block mileage with big block power when needed...

Option three is putting a supercharger, like one of those used on the cadillac and camaro models, LSA or whatever. I wouldn't have considered this back in the day but what i've seen on those TVS type rotors where there's a clutch - if that could just be disabled under most driving conditions maybe the MPG wouldn't be affected at all? I'm comparing against a turbo which otherwise should be better for not heating the charge as much, greater efficiency and no real parasitic load.

The 5.3L might have enough horsepower but hunting in gears and such struggling to keep up is bothersome to me. Lots of 90's chevy pickup guys say they prefer a 383 small block to the smaller LS's for actual work-work because of torque and that's what i'm interested in is boosting across the board torque and wondering what happens to the MPG at the same time. I know I could add 100hp with just a camshaft swap but it shifts the powerband up, a wilder cam in general might add 60ft-lbs across the board but be harder on the valve springs when using an engine over 100k miles, so I simplified the question to more cubic inches or forced induction.

I'd like big block torque say 400ft-lbs or a bit more across the midrange powerband i'm just wondering the best way to get there, what the MPG laden and unladen might be, and what the long term durability consequences are. I open the floor for general commentary...
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I don't think your requirements are that extreme. 10k isn't crazy. 400ftlbs isn't a ton.

My Ram with the 3.92 gears is rated at 11,500lbs. The 5.7 hemi has 410ft-lbs of torque.
3/4 ton or 1 ton gas engine pickup would fill the bill just fine here.

We use a boatload of Ford superduties at work, and any of the gas engines with the exception of the 5.4 in the older superduties will work fine. ( Some will not be speed demons when loaded, but work just fine. I'd imagine I'd say the same about GM's offerings and even Ram's.

I'd not venture into a customized GM V8 for this type of duty. My 2 cents...

Understandable on the diesel "fun" in the winter here, along with the usual dollar plus more a gallon for Diesel that is the norm here...
Ford F-250 or F-350 with 7.3L gasser, preferably dualies

I wouldn't bother with adding turbos/superchargers to ANY worked engine. Will be a tuning mess, mechanical nightmare, and not economical at all. You will have power and bragging rights. Will you have enough suspension or brakes when up powering a lesser truck? Better off with the future fuel expense of diesel, and an extension cord for the block/pan/battery heaters with some synth oil and antigel. Diesels in cold weather isn't rocket science, but is beyond the brain power of most consumers that cause their own problems.

Rated at and comfortable at, towing 10k are two different things. Seen plenty of blown transmissions, overheated twinturbo v6's, owner incompetence, and probably why many say ... get a diesel. Saw a pretty nice boat behind a 'not diesel or big enough' truck in a little accident... enough to cause the hitch to fail and for the boat trailer to punch thru the bumper and bed. Jacka$$ had enough power to drive too fast like a moron, but not enough suspension or brakes to deal with a little traffic emergency. The boat also came partially off of trailer and was dragged/ruined. Truck/boat were traveling south, across the center median, and ditched in the north breakdown lane. Driver was lucky that the trailer didn't smack him in the back of the head. Big HP and small brain is a bad combo!

Around here, everyone has a giant camper, a big boat, and a broken pickup truck from all 4 makes. Funny how the twinturbo'd sixes and big HP V8's get replaced with a diesel soon enough.
Big displacement: Probably reliable, enough power, big fuel bill.
Small NA engine like the 5.3: Probably (maybe?) reliable, lean on power, more moderate fuel bill as a DD.
Forced induction: Reliable or cheap, pick one if you're lucky. Lots of power. Fuel consumption somewhat dependent on what you ask of the engine.

Unless your use case involves a lot of miles unloaded, get a bigger gas engine (6.2/7.3).

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Let me get this straight. You're opposed to cams because of additional valvetrain wear/stress?
You want to slap a turbo on a 5.3L and tow with it for 100k+ trouble-free miles?

Best of luck with that.
I will still say opt for a diesel if you want piece of mind rather than over working/stressing a smallish V8. Other than the current price of fuel, I have zero complaints . My 6.7L PSD tows my 37’ TT with ease and does 90% of the slowing down for me without using brakes (exhaust brake and transmission strategy). It will also start at 0F* near instantly without any assistance (just use anti gel).
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I'll be real. Your expectations are too high and your not going to cobble up a reliable boosted 5.3. I don't care if you add sucky lower boost.
You would need to use high octane gasoline in a boosted engine while 87 octane is just fine in a 6.0L Chevy/GMC 2500.
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.
Chevy 6.2
Ram 5.9 or there 6.2 supercharged

Lowest gears you can get
3.92 or 4.10
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.
The chances of you installing a turbo on a LS base truck engine, and then driving problem free for 200k miles is slim to none. I don't care if you're only pushing 4psi through the hairdryer. Ford put millions in development for their Ecoboost engines, and first ones were not problem free. They're still learning as they go.

What is much cheaper than upping your power is being patient while towing. I used to pull over 40k with a 210 hp/520ft/lbs Scatterpillar C7. It takes many things to tow, power isn't one of them.