Author Topic: more power = better fuel economy  (Read 14722 times)

Offline Captkaos

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Re: more power = better fuel economy
« Reply #15 on: July 27, 2009, 05:10:27 PM »
My brothers Silverado gets from what I remember 18 city/ 21 hwy before the turbo, it gets 18/23 now.
We took the same trip he in his 00 Silverado (5.3L/4L60E/turbo) and me in my 87 R10 (305TBI/700R4) and he got 22.9x and I got 22.1 mpg.

4x4s I have never seen get above 17mpg EXCEPT in a diesel app.

Offline gold84gmc

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Re: more power = better fuel economy
« Reply #16 on: July 27, 2009, 05:50:14 PM »
on my truck i have 32" mud tires in the back so i take it those dont help with mileage...my mom has an 08 sierra with a 5.3L and it gets around 21mpg
92 buick century custom 3.3L

Offline exilous

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Re: more power = better fuel economy
« Reply #17 on: August 02, 2009, 08:14:31 AM »
well I'll add my .02. My 05 Dodge ram 1500 quadcab short box AWD with the stock 20s got 11-18MPG before I changed to 17 rims with 31s to try and keep the tire size the same without having to change the speedo and adding a flowmaster super 40 and an AEM brute force intake it upped it to 12-19MPG which still stinks. As for my 85 GMC I dunno yet I can hope to have it in the mid teens, but with all the performance stuff I threw into it on the engine side of things and that I'm adding a second transmission to make it a 12 speed and thats its a dually I will assume 12-15MPG if I am lucky. haha.

Offline gold84gmc

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Re: more power = better fuel economy
« Reply #18 on: August 02, 2009, 08:37:40 AM »
a 12 speed in a pickup? i didnt know you could do that lol
92 buick century custom 3.3L

Offline werewolfx13

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Re: more power = better fuel economy
« Reply #19 on: August 02, 2009, 11:51:14 AM »
I'm going to assume he means a 3 speed auxiliary, which is doable, but its application is questionable, unless you're running an old 4-53 detroit or a small cat..I've seen a road ranger of some sort shoehorned into one of these trucks, making it a 13 speed, and it was bolted behind a late model cummins, but that motor had no need for so gentle a ratio slope.
Chris
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'76 Chevy k20 LWB 6.5'x8' Flatbed
I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.

Offline Irish_Alley

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Re: more power = better fuel economy
« Reply #20 on: August 03, 2009, 12:00:34 AM »
one of my Buddys' was telling me up in NY one of his friends took a motor and Tran out of a cat. just to go 10 mph he was shifting multiple times
If you cant tell yourself the truth, who can you tell it to?~Irish_Alley

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Offline 76 k10

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Re: more power = better fuel economy
« Reply #21 on: August 05, 2009, 10:46:52 PM »
ya i dont exactly baby my truck so i probably get about 7

man your lucky! im getting 4 mpg no lie

Offline eventhorizon66

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Re: more power = better fuel economy
« Reply #22 on: August 05, 2009, 11:24:32 PM »
ya i dont exactly baby my truck so i probably get about 7

man your lucky! im getting 4 mpg no lie

4!!!  You must have a hole in your tank.
'85 C10 SWB 350 700R4 TKO600

Offline gold84gmc

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Re: more power = better fuel economy
« Reply #23 on: August 06, 2009, 10:07:20 AM »
ya i dont exactly baby my truck so i probably get about 7

man your lucky! im getting 4 mpg no lie


wow and i thought my truck was bad on gas lol
92 buick century custom 3.3L

Offline SUX2BU99

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Re: more power = better fuel economy
« Reply #24 on: August 06, 2009, 12:58:58 PM »
Well if you treat your gas pedal like an on/off switch, I could see 4 MPG in a 4x4 lol
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline 1980c10

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Re: more power = better fuel economy
« Reply #25 on: August 06, 2009, 09:42:23 PM »
I recently had a 82 lwb k10 305 quadrajet 4bbl carb and a  4 speed. 31x10 tires and I would always get 18 mpg. I did replace the dist and gave it a full tune up. then i brought to a guy to adjust the carb timing and re-route vacuum lines for the best effect. most of my driving was a combo of city and highway. I now have an 80 swb with a 250 Inline 6 2bbl carb and a 4 speed and get 17mpg after doing the same as i had done with the 305 plus a carb rebuild. it runs great but I wish i would have kept the 82 to use that 305.

Offline mean79

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Re: more power = better fuel economy
« Reply #26 on: August 07, 2009, 02:24:24 AM »
my 79 gets 15mpg its 4x4, but its a 4 speed, and my dad said his 78 with the automatic would suck it out of the tank as if it was goin outta style.

Offline jimbo

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Re: more power = better fuel economy
« Reply #27 on: August 07, 2009, 09:40:09 PM »
I've always been a proponent of the adage more power/efficiency = more mpg.  I cannot recall how many vehicles I have swapped 2 barrel carbs for 4bbl's and added an aftermarket intakes as well as exhaust and gotten better mpg nearly everytime.

Offline malibu795

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Re: more power = better fuel economy
« Reply #28 on: September 22, 2009, 09:11:49 AM »
I've always been a proponent of the adage more power/efficiency = more mpg.  I cannot recall how many vehicles I have swapped 2 barrel carbs for 4bbl's and added an aftermarket intakes as well as exhaust and gotten better mpg nearly everytime.
its fact you increase the effecientcy of the motor to burn X amount of fuel.. and the work stays the same you will get more work done for the X amount of fuel.

easier it gets air in and out, and better burn the effcience will go up.  also getting the motor to runs at its most efficent rpm band is key
adam wildman
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Offline jimbo

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Re: more power = better fuel economy
« Reply #29 on: September 23, 2009, 04:54:34 PM »
I've always been a proponent of the adage more power/efficiency = more mpg.  I cannot recall how many vehicles I have swapped 2 barrel carbs for 4bbl's and added an aftermarket intakes as well as exhaust and gotten better mpg nearly everytime.
its fact you increase the effecientcy of the motor to burn X amount of fuel.. and the work stays the same you will get more work done for the X amount of fuel.

easier it gets air in and out, and better burn the effcience will go up.  also getting the motor to runs at its most efficent rpm band is key
I completely agree.  I am hoping for a decent improvement after this winter when I add my longtube headers and exhaust to the little 305.  On the rpm note, I really need to upgrade my 2.73 rear.