Gen III/IV Chevy LS motor swap fuel mileage

[Cataldo]

What is your average mpg with your Gen III/IV swaps? Please give some insight into your set up as well, transmission, gear ratios, tires, roof rack, etc. Also let us know what modifications to your motors you did (cam swap, intake, etc) and lastly your driving habits and conditions.

Thank you

[hutcho]

Following

[Nikkormat]

I won't vote because my LS isn't swapped... But I average 12.6 with the 5.3 LM7 in the family sierra. 3.73, 33's (roughly), and a 4L60E.

[Cataldo]

Any and all input helps build a better picture

[Cataldo]

I was hoping more people would have cast in on this pole. Anyone care to divulge their fuel consumption with us?

[DustinLangston]

I had a 5.3, stock internals/tune, with headers and cold air intake. Running 31" BFG All-Terrains with a 2"lift and the stock Wagoneer roof rack. I consistently got 2-23 mpg on the highway and 17-18 around town. My axles were running 3.31 gears and I used the 4L60E trans. I am actually going to start building another one right now with an LS swap but with bigger tires (33's most likely) and possibly 4.11 gears. I'll let everyone know what we get on that one. My build thread will begin this weekend on the new LS swap (into a 79 Golden Eagle restoration). Make sure to watch for it.

[Cataldo]

I had a 5.3, stock internals/tune, with headers and cold air intake. Running 31" BFG All-Terrains with a 2"lift and the stock Wagoneer roof rack. I consistently got 2-23 mpg on the highway and 17-18 around town. My axles were running 3.31 gears and I used the 4L60E trans. I am actually going to start building another one right now with an LS swap but with bigger tires (33's most likely) and possibly 4.11 gears. I'll let everyone know what we get on that one. My build thread will begin this weekend on the new LS swap (into a 79 Golden Eagle restoration). Make sure to watch for it.

That awesome fuel mileage. What transfer case?

[DustinLangston]

NP208

[Cataldo]

That is what I am thinking as well. How did it do with the 3.31's?

[DustinLangston]

Great going down the freeway. Just above 2000 RPM's. For towing it could have been better. But it was fine.

[Cataldo]

That gives me hope for 33s and 3.54s with a 700r4/4l60e

[area52]

Jay,

Off topic but I'm in San Bernardino also and also doing this swap (slowly). Send me a pm if you want to shoot the breeze or compare notes sometime.

Wade

[Cataldo]

Jay,

Off topic but I'm in San Bernardino also and also doing this swap (slowly). Send me a pm if you want to shoot the breeze or compare notes sometime.

Wade

Very cool, I am near Cal State

[DustinLangston]

Also important to add. I live in Utah so I was able to get rid of all the smog equipment and EGR with my swap. I don't think you guys will be as lucky being in California.

[Cataldo]

1975, I don't have to have anything as well

[ProTouring442]

The worst I've gotten is 16-17mpg while running 80mph in the mountains on our way to Albuquerque, NM. Otherwise, I run around 19-20mpg.

[Jeff from Iowa]

I don't care about mileage but I did drive it 100 miles and filled it up. It was over 16 mpg but I don't remember specifically as its just a sunday funday driver.

[Cataldo]

Thanks for the input! very promising results. Obviously not going to pay for itself in fuel mileage alone, but for enjoyment factor it will take car of the costs quickly in my opinion. The 195/260hp 350 chevy that is in it now is adequate for now, but with towing the Camaro out to Vegas and back ~500 miles round trip, I would have liked to had more power. Plus I can pull the motor out and swap cams and swap it into my chick's sbc YJ that has a tired 305 in it!

[DustinLangston]

You're coming out to Vegas? I'm just up the road in Cedar City, UT.

[Cataldo]

I want to replace my tank with a rear mount, so I'll run a 2 door blazer tank with an appropriate fuel pump and that takes car of my fuel system. Motor mounts and that is it other than the motor and associated wiring, which a buddy's buddy does for like $250 with a mild tune (Getting rid of the nonsense mostly). The 6.5 Diesel is still an option, but the lack of diesel in remote places is a major turn off. I'll have to try and get a better idea of diesel availability way out in the boonies.