Fuel economy C10 with carb

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CapAhab

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Suburban C10
Engine Size
350
Hej community !

I have a stock C10 Burb with a 350 engine and auto (not sure which version) from 82 rather new edelbrock carb fitted and runs well, what type of mpg should this set up be expected ?
Recently did a trip from mid of Sweden (Gothenburg area) down to the Nederland approx. 1200 km (745 miles ish) one way mostly freeways and "normal" roads, i sort of end up at 1,6 - 1,7 L/km (13-14 mpg) would that consider to be "normal" ?.

And of course the tread shall consist of pics :)

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CapAhab

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Suburban C10
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I should have been 1,6-1,7 per 10 km sorry
 

Vbb199

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That doesnt seem bad for a carbed 350
Being an 82 i guess it could be a 3 speed th350 automatic, or a 700r4 (4 speed automatic)... if its stock

With the current tire size, i'd expect a little better than 13-14 though

Whether its a 3 speed or a 4 speed automatic will really determine your expected MPG though bottom line.

With a 4 speed automatic i'd expect better than 13-14.

With a 3 speed automatic thats reasonable
 

SquareRoot

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That doesnt seem bad for a carbed 350
Being an 82 i guess it could be a 3 speed th350 automatic, or a 700r4 (4 speed automatic)... if its stock

With the current tire size, i'd expect a little better than 13-14 though

Whether its a 3 speed or a 4 speed automatic will really determine your expected MPG though bottom line.

With a 4 speed automatic i'd expect better than 13-14.

With a 3 speed automatic thats reasonable
:laughing1:10-12 like every squarebody ever.
 

TotalyHucked

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I would say that's about as good as you'll ever see. My '85 (305, T350, 2.73 rear gear) got 12 on the highway, 12 in the city, 12 uphill, 12 downhill, 12 sitting in the driveway, 12. But it had 2 cylinders down on compression. I have a few friends that have seen as good as 14-15 with a healthier 305 or 350 and a 700R4.
 

3 Ton

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My 78 gets 19 mph in the summer, and 12 mpg in the winter (ethanol).
Its a 6000 lb lifted 4x4 Suburban.

If your going for fuel mileage, go with a Rochester 2 barrel. My buddies tri power get better mileage than any 4 barrel.
Just running foo the center carb.

For all you Holley new buyers, there is no parts no support for many of Holley's Chinese made carb. Enjoy
 

Bextreme04

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My 78 gets 19 mph in the summer, and 12 mpg in the winter (ethanol).
Its a 6000 lb lifted 4x4 Suburban.

If your going for fuel mileage, go with a Rochester 2 barrel. My buddies tri power get better mileage than any 4 barrel.
Just running foo the center carb.

For all you Holley new buyers, there is no parts no support for many of Holley's Chinese made carb. Enjoy
No, lower mileage in winter has nothing to do with ethanol content. You can actually get BETTER fuel mileage with a higher ethanol content up to 30% if you are properly tuning for it... but legally there is never more than 10% ethanol content in your fuel anywhere in the US unless it is E85 or you have selected a higher percentage in a station with a blender pump. In the PNW, there are only 2 fuel stations in the entirety of Oregon/Washington that I have been able to find to provide E85. That is a single station in downtown Portland and a single station just south of Eugene.

Ethanol has a hard time with cold weather, so they actually REDUCE the amount of ethanol in the fuel and add other cold weather package additives to help prevent the fuel gelling or water intrusion. The lowering of the fuel mileage in winter is almost always due to the cold start cycling and people leaving their vehicles idling for extended periods of time with the choke on or the fuel mixture excessively rich to support warmup. Additionally you are almost always running your AC compressor to support the defrost cycle as well. This all adds up to a significant reduction in fuel mileage.
 

Vbb199

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:laughing1:10-12 like every squarebody ever.


Naw, my ol' 90 burban got 22 on the hwy

But that was a gutless tbi350.....stock
700r4..... stock
Stock 3.08 axle with a stock tire/wheel
2wd
Stock stock stock stock
 

ali_c20

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My K5 is 10-13 mpg. Depends mostly on my right foot.
 

CapAhab

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So as i expected its kind of normal :), depending the right foot etc
 

Poodlehead

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My 78 gets 19 mph in the summer...

If your going for fuel mileage, go with a Rochester 2 barrel. My buddies tri power get better mileage than any 4 barrel.
Just running foo the center carb.
My 77 gets ~ 13 mpg with a stock 4 barrel Rochester, 350, and 400 trans.

I'm more interested in gas mileage now so maybe I need to look into a Roch 2 barrel??? Would you know of a specific carb # that would be a 'bolt on' swap or is it that simple?

Thanks in advance!
 

77Dmax

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Hej community !

I have a stock C10 Burb with a 350 engine and auto (not sure which version) from 82 rather new edelbrock carb fitted and runs well, what type of mpg should this set up be expected ?
Recently did a trip from mid of Sweden (Gothenburg area) down to the Nederland approx. 1200 km (745 miles ish) one way mostly freeways and "normal" roads, i sort of end up at 1,6 - 1,7 L/km (13-14 mpg) would that consider to be "normal" ?.

And of course the tread shall consist of pics :)

You must be registered for see images attach


If you haven't tuned the new edelbrock you are leaving a lot of power and mileage on the table.

Also timing with vacuum advance will make a big difference.
 

Ricko1966

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c20
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350
My 77 gets ~ 13 mpg with a stock 4 barrel Rochester, 350, and 400 trans.

I'm more interested in gas mileage now so maybe I need to look into a Roch 2 barrel??? Would you know of a specific carb # that would be a 'bolt on' swap or is it that simple?

Thanks in advance!
It's not that simple,the right way would be change carbureator and intake manifold. Your stock Quadrajet is a small 2bbl until you get into the secondarys,just drive with a lighter foot. Put a vacuum gauge in the car so you can see when you are really using fuel.
 

newguy11

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C/k 10
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305/350
I just finished a 400 mile trip.
1985, single cab 2WD 8’bed
350, quadradet. All stock except for summit 1102 cam.
3.08 rears
TH 350
Cruised around 75mph

15.25 MPG
 

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