454 mileage
 

i found a 454 at the local pick and pull in a '89 suburban. i know they like there gas but i was curious what kind of gas mileage i would get with a 454 carb,nv4500 trans,4.10 ratio, and 33 inch tire?:chevy:

Re: 454 mileage
 

What mileage? Hope you have two tanks!
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Re: 454 mileage
 

I think it might be mathematically easier to calculate that combo in feet per gallon. Haha.

Realistically though, you can probably expect 8-10 mpg.
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Re: 454 mileage
 

Every 454 ive been around gets 10 driving right. Dramatically less heavy footed
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Re: 454 mileage
 

i've stated it before. i will state it again:

BIG BLOCK ON THE STREET = FINANCIAL SUICIDE


i think the only way you can get any decent mileage out of a big block is to utilize very high compression----14.1-to-1 if that's even possible----which would necessitate using water injection (or as high compression as possible), headers and hi-gear such as 2.56.

Re: 454 mileage
 

well now im running 355 with 11.5 to1 comp ratio through a sm465, 308 gear ratio and 33 inch tires and im running 7.5 mpg and thats driving with a light foot. the reason i wanted a 454 was for torque

Re: 454 mileage
 

My TBI crew dually gets around 9mpg/empty/loaded/pulling seems not to make much difference. I get a little better on flat hiway and a little worse going over the mountain passes here in WA.
FWIW It is thirsty but then im not paying making payments on a 50k $$$ diesel truck i would only drive every other weekend. Total operating cost is actually pretty low if you look at it that way.:lol:
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Re: 454 mileage
 

What are trying to do? Towing?

Re: 454 mileage
 

My 82 C-20, 454, TH-400, 4:10 gets 10.2 mpg whether I'm towing, loaded down or empty. My 1998 C3500 ext-cab dually, TBI 454, 4L80, 4:10 gets 10.8 empty and 8.8 towing a 8200lb trailer and boat.

Re: 454 mileage
 

i live on a dairy farm so it tows wagons and a trailer for my classic tractors

Re: 454 mileage
 

Street/highway/empty/loaded/uphill/downhill/sea-level/high altitude = 10mpg. Period.

Re: 454 mileage
 

If you shut it off going downhill you might get a little better, LOL

Re: 454 mileage
 

Had a 454 in my stepdads 67 Chevelle before we sold it. Edelbrock intake, Holly Carb, 3:73 gears and TH400 later swapped to a Muncie 4 speed. Got pretty much 8 the whole time. Maybe 10 downhill, not running, with a tailwind and on a trailer....you get the point....
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Re: 454 mileage
 

About the same here.
82,4x4,454,t-400,with 373 rear.33x12.50 tires.
The only good thing is,it gets the same milage up hill or down!
With or without our 28'travel trailer.
9 to 11 per gallon is about normal.
BUT,nothing beats it for towing!
Mike.:chevy:/:gmc2:

Re: 454 mileage
 

But no power steering/brakes! :eek:

Re: 454 mileage
 

How bout the 2005ish 8.1 with an allison?

Re: 454 mileage
 

My 83 C20 2wd reg cab LB best mileage with gear vendor used frequently got 11 mpg city, 13 mpg highway. Realistically, I get 9 mpg city in constant stop and go traffic (the only place I drive now.) The lowest I got was 8 mpg city hauling dirt in my dump conversion. However, the 76 C20 350/350 did not get any better gas mileage. I think when you are hauling around an extra 1000 lbs. of dead weight compared to a 1/2 ton you are not going to get good gas mileage even if you had a 4 cylinder.

Re: 454 mileage
 

2 gallons = 1 mile

Re: 454 mileage
 

get the nv4500, leave the 454

Re: 454 mileage
 

Why not do a diesel swap? a 6.2 will bolt in have enough torque and get better mileage.

Re: 454 mileage
 

Ok here I propose a idea that isn't employed often

Cummins 6bt swap, the torque and fuel mileage you need and planty are available
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Re: 454 mileage
 

Guess I'm screwed then with the 496 that I built. :) Oh well, I built it for speed not for economy. I know that some stock 396's that get good mileage. My parents have a '66 Caprice that is a bone stock 325hp that, they have gotten 20mpg out of. But it also has 2.73 gears in it too.

Re: 454 mileage
 

If you can set it up in front of a 4L80E, it will help a lot!

And for all you diesel swap supporters...I can completely overhaul a 454 for less money than you can have a diesel injection system rebuilt. And if I add a turbo similar to what comes stock on most diesel engines, I'll out pull 'em and shave 400lbs off the nose of my truck.

Re: 454 mileage
 

I wouldn't swap to a diesel either. For what he is doing, its not worth it. Alot of money for nothing. Maybe he could find an '01 and up 8.1 instead.

Re: 454 mileage
 

Are you going to tow the tractors off-farm or on-farm?

Re: 454 mileage
 

I take it they are show tractors.

I thought about a swap last night, and if you did something like a 8.1 conversionfor are going to spend probably 3k to get it right and you will pick up 2-3 mpg, so let's use the high side. If you are currently getting 12 (for easy math) and you go to 15 then you will pick up a gallon every 60 miles, at $3.50 per gallon you would have to run over 51,000 miles to break even.

$3000 / $3.50 = 857.14 X 60 = 51,428

So do it to save money is a misconception, doing it for fun or better power it can be justified because of desire, but not economics. And yes, other swaps can be done more effeceintly but the math is still there and 3 mpg is a pretty good pick up.

Now an LS swap MIGHT make the math work because you will get more than 3 mpg and probably be well less than 2 grand if you plan it right.

Re: 454 mileage
 

I say go with the 454. Your 355 or 350 is not getting super great mpgs anyway. It is unlikely that overdrive will come into play pulling wagons around the farm. The deep torque at low rpms will.

My 355/350 with 3.08 gears X2 peg leg still only got about 10mpgs on the highway. So, 2x the torque and about the same mpgs? Seems good to me. In fact, I had a plan in place, but I did not get to the big block fast enough. :waah:

Re: 454 mileage
 

Not really my vortec 454 with a 4L80 In my crewcab gets 10 12 if my wife drives
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Re: 454 mileage
 

My '82 K20 (454/SM465/NP205) with 4.10 gears and 35" tires gets 11mpg...loaded or unloaded, trailer or no trailer.

Re: 454 mileage
 

That's the issue. It's not a lot Of money if you find a cheap decent running engine. Getting it in there is the issue. Really if he can pull it off it's perfect and will cost as much as a good Lsx swapp with overdrive in the end
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