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

Newer diesel on 3/4 ton and buy fuel at Mobil/Exxon. Block heater if needed. Diesel fuel has come down in price and I get it for $4 a gallon with Mobil/Exxon 10 cent discount.
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...
I personally prefer the super low rpm torque of a turbo engine.
Gas or diesel.

Less down shifting needed.
We have a 1974 Chevy camper special with the 454. Gets 6ish mpg regardless if it's empty or pulling 15k+ lbs 😂

I'm all for fuel efficiency but a truck should be about durability. That thing has been worked pretty hard it's whole life and shows no sign of slowing down.

I know people have differing opinions but I work on vehicles every day for a living, the smaller engine boosted trucks usually need a lot more costly repair than the older basic V8's or straight six's.
I have owned three of these trucks...towing. What planet where you on when you chirped the tires towing 12,000 pounds?
For real, the 5.3 can hardly chirp the tires empty 😂. I drove a 6.0 Silverado home from my used lot the other day and even that was kind of a dog.
Diesel but I'm biased and if not turbo especially with elevation changes. Newer diesels have no problem in Minnesota as long as your batteries are decent which you could say even for a gasser.