# Mileage, gearing



## mstyles0927 (Nov 30, 2000)

I had a 1976 1/2 ton 2WD LB AT truck with a factory 350 in it. When I wrecked it, I bought a 1980 1/2 ton 4WD SB MT truck with a used-up inline 6.

When the inline 6 finally gave up the ghost, I pulled the 350 from the 76 and dropped it into the 4x4. I have rebuilt the carburetor myself with a kit from AutoZone(2 barrel), replaced the plugs and wires, checked the timing, etc (you know, a basic tune-up). I left the 4 spd manual tranny in the 4WD. Also, I know the 76 LB had a bigger gas tank (I think 18 or 20 gallon) than the 80 (16 gallon). 
But it seems like the 4x4 really drinks the gas much harder than the 2WD--I hit the station to refuel a lot. Is this common--I haven't made the time to pull the rear differential to look at the gear ratio, but this thing is really hitting the old wallet now?
Last check on the highway trip to the lake I got just under 13mpg. In the city (with all the traffic and lights) it drops to around 11-12mpg.
Any ideas out there?


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## John DiMartino (Jan 22, 2000)

4x4's do use quite a bit more fuel than 2wds especially in older rigs.you might have like a 3.73 in the 4x4 and had 3.08 in the 2wd,which will make it even worse than it should be.


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## mike reeh (Oct 8, 2000)

man you get 13mpg!! i envy you  

a quadrajet or other 4bbl will wake up the motor at full throttle but say bye bye to gas mileage...

like john said, its probably in the gearing, plus its a heavier truck. i definately know what you mean when you say its really hittin the old wallet.. 

good luck

mike reeh


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## 85w/350 (Sep 15, 2000)

*WoW*

I also envy you I drive a 2wd sb GMC w/350 and it gets 10-1/2mpg in the city and 12mpg on the highway...i just mounted some 31 inch tires in hopes of helping my highway mileage by slowing down the RPM's a bit...city probably got worst I'll be filling up soon so i'll post another within the next few days


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## Joseph Meidling (Jan 11, 2001)

I will be looking for a 4wd, 1500 series to commute back and forth to work in. I was thinking about the 4.3L?? Any input would be appreciated. The commute is 30 miles each way.


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## mstyles0927 (Nov 30, 2000)

Thanks for all the input. It seems like maybe I don't have it too bad, compared to some of you guys! I guess you have to give up the gas mileage for the privilege of driving one of the best trucks in the world!

Thanks for all the input.


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## Mowman (Jun 18, 2000)

*25 MPG + !!!!!!!!*

Yes, 25 MPG pulling my trailer and equipment. I bought this truck new (ordered) it in 1998. I wasn't mowing much then and wanted the best MPG. S-10 w/ 2.2 Vortec 4 w/5 speed trans. I'm now pulling a 5x10 open trailer w/ Walker mower and misc. equipment, about 1900lbs. It handles it fine. Next truck will have a 4.3 V-6 and auto w/ 4X4 for snow removal. But hey for now it's getting the job done. 
And I'm whining at 25, don't know how you guys do it, 8-12 MPG? 
Mowman


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## 85w/350 (Sep 15, 2000)

*give it up*

Mowman, 
If you are complainig about 25mpg somethig is wrong...I see you also have a 4cylinder compared to our 8's...the 4.3 is a good little engine and I have seen up to 30mpg out of one in an s-10, but it was highway mileage, not a 4x4 and definately not pulling a 19,000lb trailer...now a days if you can even find a chevy truck much less any truck (I'm talking real trucks 1/2tons and bigger) that can get 25mpg you found yourself a deal....

mstyles0927
In my opinion sometimes you have to give up the mileage for power and for driving a dependable truck that will run practically twice as long as any other vehicle...my mileage is bad and i wish it were better and i am going to change the gearing soon hopefully to 3.08's from 3.73's...


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## roland26 (Nov 13, 2000)

*mileage and gearing*

my 84 gmc has a 350/300 gm crate engine with hedders,edelbrock manifold and quad jet. it has a 700 with 28" tires. with the 308 gear it runs about 2000 rpm at 65. 
and it get 13mpg. but according to the vac gage I am in the 
carb alot.I think my final gear is 2.10 (in od) and that is toooo high. I am going to 3.42 (mabe a 3.73) and mabe I want be in the carb so deep. with the 3.42 I think the final drive will be about 2.60 and the 3.73 about 2.80. do these figures look correct. I dont expect 17 to 18 mpg but 14 to 15 would be nice. roland


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## 85w/350 (Sep 15, 2000)

I heard that the 3.42 with the 700 tranny is a nice setup as far as gearing and gas mileage...as far as the numbers i'm really not sure


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## MTCK (Feb 13, 2000)

The 700r4 transmission has a 70% overdrive, which would give you a 2.61 final drive ratio with 3.73 gears or a 2.40 final drive with 3.42. Hope this helps.


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## 2401 (Feb 3, 2001)

*Mileage and gearing*

Considering that you're running a 4x4, and with all the other information you have posted, I don't think you're doing that bad. That transmission sounds like the same one in my welding rig, (1979 Chev C-30 dually, 350 gas) around here we call them "farmer four gears". Good transmission, that grunt low 1'st gear is nice for launching and pulling but there isn't much top end! That will really make a difference in the mileage. Hey, 85w/350, couldn't have said it better myself. Sure my truck (1975 GMC C-35, 350 gas, T400, 2wd dually) uses more fuel (I'm lucky if I hit the 10 mpg mark!) but it doesn't cost me a lot in other ways. It's paid for and I do pretty much all my own repair work. I guess my employer feels the same way too, that's why he's running the '79 I drive and just put a bunch of $$$ into a body job and mural on the hood.

1975 GMC C-35


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## John DiMartino (Jan 22, 2000)

Joe M,the 4.3 V6 will be fine in a 1500 4wd for commuting,just dont put big tires on it,it'll bog it down.I know a couple of guys with them,and they test drove the 4.8 270hpV8 first,there isnt a very big difference in power,the 4.3 has more torque at lower RPM's and has 200hp on the top end.If you plan to tow anything over 3000 lbs,on a regular basis,go fop the 5.3/V8.


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## steveair (Feb 24, 2000)

Hello,

Not to say it can't be possible, but I find it hard to believe a s10 is getting 25 mpg, especially pulling a trailer.

Just got rid of my 99 gmc sonoma, 2wd.5 spd manual/2.2 liter, and the best mpg I got was 23 on the highway with no load. Avg, commuting 30 miles each way to work was around 20-22. No way can I imagine getting 25 mpg out of the 4 cyl pulling a 2k trailer. 

I once had a 2.6 liter isuzu pickup, and that never did any better than 23 or so on the highway also. If you are seriously getting 25 mpg pulling a trailer, then I would keep that truck forever and sell it on ebay as a 'rare vehicle' because it doesn't sound possible. Maybe, and I mean maybe, 16-17 with a trailer, but that I doubt. I use to put a yard of mulch in the back of the truck and I couldn't leave 4 th gear. Just no way.

steveair


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## Chopper Lover (Feb 6, 2001)

I know it has been a while since the original post but I was wondering if you have manual or automatic hubs on your front end.

Automatic hubs, depending on the transfer case, will sometimes activate themselves when any slip is noticed. They are also creating drag in your sytem while you are driving causing a need for more fuel to be used.

For less than $80 you can easily install manual hubs and you will see a slight increase in your fuel economy. I had switched mine in my old 1982 because I could never tell if they had disengauged when I shifted back to 2WD. I picked up about 1 MPG.

Just an idea.
Mark


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## RTallday (Feb 27, 2001)

I get 10 miles to the gallon in my 79 K-20. Thats with 33 inch tires!! The 4X4 will generally get worse gas mileage than the 2 wd, cause there is more weight in a 4X4. Also, u have the transfer case, and the tranny is cast iron, so theres a lot more weight there. I also have 4:10s. I would guess you have 3:23s or 3:73s. Good luck.

-Rich


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## mike reeh (Oct 8, 2000)

what kind of tranny are you talking about? a manual gearbox i take it..

but god you said it all when you said the xfer case is heavy! what a freakin monster a 203 and 205 are.. not as heavy as a 3/4ton rear axle! 14 bolt axles are unholy beasts.

all that added weight PLUS a front axle, its hard to beleive they dont get MUCH worse mileage vs. a 2WD..


mike


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## mstyles0927 (Nov 30, 2000)

*Yes, Manual Hubs*

Chopper Lover, I have the manual locking hubs. I thought about looking for automatic hubs to switch, but figured the time and expense were not worth it. The 4 spd manual and probably lower geared rear-end probably make the mileage as bad as it is.

I do 'lock' the hubs every 2 or 3 months and run them locked but in 2WD for a day or two when I haven't used the 4WD in a while. I had a friend tell me this was a good idea to keep the manual hubs in good working order. Anybody ever heard of this? Good or bad?


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## Chopper Lover (Feb 6, 2001)

Yes, it is a good idea to lock the hubs from time to time to keep them lubed up and working freely. When I switched mine to manuals the hub manufacturer (Warner, I think)recommended once a month for 2-3 miles. I would guess what you are doing will work just as well.

As for switching to automatic hubs I would say no. Normally you will know when you are going to need them and can lock them in advance. If you wake up and have a foot of snow on the ground you can always lock them as you clean off your truck. 

I got rid of the automatic hubs on my 1982 because that model truck required you to back up for 20 feet or so to unlock them. I would always hear one unlock right away, but never the other. Rather than taking the chance of burning one up, I switched to the manuals. On any truck I order from here on out you can be sure I will go with manual hubs if it is available. 

Mark


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## mstyles0927 (Nov 30, 2000)

*Thanks*

Thanks for the info.

As I mentioned, I have the 3 spd + 'granny gear' manual tranny. Is it a good idea to mess with the rear gears to move to something like a 3.08 or the like in a 4WD? I can get the rear-end from my old 2WD truck if needed, but I am afraid of 'messing up' the 4WD or something.


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## 2401 (Feb 3, 2001)

Because your front & rear wheels need to turn at the same speed, if you alter the rear end gears you will also have to change the fronts to match. If the front & rear drivelines are turning at different speeds, it will cause problems - the more drastic the mismatch the more the more drastic the problems!

Unless you can get a set of axles out of another 4x4 to bolt in, I would be inclined to leave things the way they are. Just my opinion!


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## farmboy4 (Mar 29, 2001)

*2 barrel carb*

Aren't the primary barrels of a two barrrel carb bigger than that of a 4 barrel. therefore if you drive reasonable you will actually get better mileage from a four barrel. I've heard of cases where a 350 with a 4 barrel got better mileage than a 305 with a 2 barrel.


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## reallyrusty (Mar 18, 2001)

If you are talking about a quadrajet you are correct.
The metering jets are are also adjusted by engine demand so they can be very efficient and the primaries are tiny. Just remember thou if you change the carb you have to look at the (breathing) rest of the engine (ie cam, timing,exhaust)
To make it all work.


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## Albemarle Lawn (Mar 31, 2001)

*AN S10 IS NOT A TRUCK*

We are only allowed to speak of real trucks here.

Also, 4.3 V6 is junk. Most have balance shafts. They are very weak for towing, and a starter is $150 at a cheap parts store.

I changed my 4.3 GMC 1500 to a 383 Stroker with a towing cam and higher compression. Also went 10 4:10 rear. With a 700r4 the acceleration rocks unloaded- I smoke 5.0 and 4.6 mustangs at stoplight derby.

8 MPG on premium fuel sucks, but it has enough torque to pull a small church off of its foundation.


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## plowjockey (Dec 3, 2000)

Funny but my 91 S-10 4.3L used to tow an 18' Starcraft open bow boat that weighed 1,565 lbs dry and had a 710 lb trailer and never had a bit of trouble towing or pulling out of any boat ramp that I ever encountered. Not to mention I could blow the doors off Monte Carlo SS's with a chip at will.(no my truck was stock the other vehicle had the chip)
Since I work at the truck plant that built my truck (in the chassis dept.) I can say with knowledge and facts to back it up that this S-10 was built truck tough as were all of our trucks.

Bruce

Oh yeah I loved the 22 mpg on the highway cruising at 72 mph. and passing all of those guzzlers while they were filling up. No offense meant to guzzler drivers.


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## Albemarle Lawn (Mar 31, 2001)

*MONTE CARLO SS*

Funny you should mention one of my favorite cars.

It's just a darn shame that they had 305 engines and carburetors.

A 350 LT1 or Vortec 350 can really wake up an SS since they came with factory 3:73 gears and limited slip rears.

BUT beating a 305 Monte Carlo with a 4.3 S10 is a breeze. Beating anything with a 305 is easy unless you are in a Hyundai or something.

How about a LT1 s10? There's a rocket for you!

KB


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## plowjockey (Dec 3, 2000)

10-4 on the rocket. If we just didn't have E-Check in this part of Ohio I could really build some street fun.

Bruce


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## Alan (Mar 2, 2000)

*Opinions are like Anuses,,everybody has one and they all stink*

I'm pretty please with the 4.3s that are in our two S-10s. The 88 isn't quite as strong as the 91, but it does ok. The 91 does right fine pulling about 2500 lbs of trailer and load all summer and they both grunt good behind 8' plows.

As far as S-10s not bieng "real" trucks, they're a lot more real than some of the minis are. Mine work hard and seem to be up to the task. What more do you want?


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## 2401 (Feb 3, 2001)

*Think first, then type.*

I won't get into a discussion of what's faster etc, but I will say there's nothing wrong with an S-10. I certainly wouldn't say they are "not a truck" - anymore than a Mack Mid-Liner is "not a truck" as compared to the Mack Super Liner I used to drive.

Each truck is designed for a different application. An S-10 may not be big enough to serve as the welding truck I drive at work, but there's also lots of jobs where the S-10 is better than the big dually - a mechanical contractor who I occasionally do pipe welding for has one & it's perfect for them. (That dually welding rig would make me one of the "guzzlers" you passed at the gas station Bruce  !)

Think first before typing. Making a statement such as "S-10 is not a truck" indicates to others a certain lack of forethought, and perhaps lack of knowledge as well.

[Edited by 75 on 04-01-2001 at 12:41 PM]


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## John DiMartino (Jan 22, 2000)

An S10 is not a truck-right,You need glasses,first off,The sS10 might be small,but it has a more substantian chassis and frame than any other small truck out there,and the most torque with the 4.3 V6.The 4.3 is a great engine IMO,I know of 5 right now with over 300K on them-all city driving,never had the valve covers off.Towing performance with the L35 4.3195Hp is excellent.The blazer can pull proportionally better than the full size 1500 IMO.Id love to see your 383 stroker pass emissions.


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## plowjockey (Dec 3, 2000)

OK White flag. Albermarle and I got thta straightened out very well.
The S-10 has a good substantial frame and plenty of power but may not be every driver's cup of tea. 
As a matter of fact the 383 stroker, although admittedly a tough cookie to get through E-Check, is a very strong set up. When I worked on a pit crew for an "E" modified roundy rounder it was the class of the field at least in our case.
As for the Guzzler comment I made. My other "car" is a C-70 dump truck with a 366 big block and a 650 Holley that must be very friendly because it wants to stop and say hello to every gas station thatwe come to.

Bruce

[Edited by plowjockey on 04-01-2001 at 09:09 PM]


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## 85w/350 (Sep 15, 2000)

I drive a fullsize guzzler with lots of power....and I have much more bedspace than any s-10 can ever provide...However I'll agree that the s-10 can probably manage to pull the same load as a fullsize but an engine can only withstand so much strain...anything with the right gearing and setup though can do a great job at whatever the owner has in mind. I have ridin in a s-10 when we raced the same year full size chevy both had chips the 96 s-10 a 4.3 the 96 chevy 350 and that s-10 smoked the fullsize by more than a truck length...hp for hp the fullsize has it but when you take into account the weight of each the s-10 has a definate advantage....as far as collision test and how safe I feel the full size is for me...overall I am not a fighter within the family


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## Albemarle Lawn (Mar 31, 2001)

*S10*

Okay, folks, I apologize for knocking the S10. I have never even driven one so I was being judgemental.

Here is where I am coming from: I have owned several half ton trucks and recently bought a 3/4 ton Chev Suburban. I got sick of wearing out axle bearings, weak GM 10-bolt rears, small brakes, swaying trailers, etc. I swear I will never buy anything less than 3/4 ton 8-lug trucks with diesel engines.

This is because I routinely tow 7,000+ lbs. But an S10 is a good little "truck" for towing up to 3,500 lbs. And great for running estimates and going to the store to buy grass seed.

How about an S10 with a 383 Stroker, Vortech heads, and 4 spd auto with 3:42 gears. That would be a joy to drive! Torque to accelerate and tow and never hunt in and out of overdrive on hilly terrain.


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## 85w/350 (Sep 15, 2000)

At the last local car show I went to they had a early 80's s-10 blazer with a stroker 383 in it. Looks like it takes talent to free up enough space to drop on of those suckers in


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## 2401 (Feb 3, 2001)

Bruce - white flag is out!

Albermarle: OK, I admit I was a little hasty with my reply. Sounds like you use your trucks in an application where light duty won't cut it - for the same reason, 1/2 ton trucks have never worked out as welding rigs at my work.

S-10 with a 383 stroker sounds like a good combo (I like my small-block Chevys) - just don't go t-o-o big on the trailer because you'll still have the smaller tires/brakes/etc!


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## mason.rendowski (8 mo ago)

send me a picketer of the monte carlo.


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## Mike N (Dec 21, 2008)

Zombie thread revival!!


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## mason.rendowski (8 mo ago)

what kind of car and what year.


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## BossPlow2010 (Sep 29, 2010)

mason.rendowski said:


> send me a picketer of the monte carlo.


Wow! Insanely old thread to bump, welcome to plowsite, going to lock this thread, I’d suggest starting a new one.


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