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?