Pleased with MPG results. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

C10Silverado79 · 08-01-2010, 10:59 PM

After the carb rebuild, I think I've finally got all the vacuum leaks plugged and the timing adjusted as good as I'll probably get it. Ran to Pittsburgh an back pulling a small utility trailer, today to take some furniture out to my son's new apartment. 420 round trip mostly highway. The truck is running real smooth now and the trip average was 14.3 MPG. I ran mostly between 60-65 but the GPS said I got up to 75 at least once. The best I used to get was 10 MPG so I'm pleased with the improvement. I have a 350 w/ Q-Jet 4bbl and a TH350 trans. (no idea what the rear ratio is)

84c10tony · 08-06-2010, 11:23 PM

Beats my 13mpg 65-70 mph with a 305 and 700r4, and no trailer lol.

iroc12valve · 08-07-2010, 12:02 AM

beats my 10 mpg's with a new F150

in the 5 years/230,000 ive never gotten better than 14 Mpg and it runs so smooth you cant even hear it, my old 89 camaro got 27 MPG Average as high as 34 one time all hand calculated, ran kinda rough even with a new motor, smelled like an old chevy and had very good power.... Gotta love Emissions (B.S.)

Rpratt · 08-07-2010, 07:25 AM

I have a one ton dually 4x4 with a 6.2 turbo. I got 19.6 and 19.1 from the last two tanks of fuel.
I have been planning on doing a cummins swap, but I really like this engine for the mileage.

Prerunner1982 · 08-07-2010, 07:39 AM

My 87 GMC with a 5.0 TBI and 700R4 got 16mpg in town, however my 82 Chevy with carb'd 350, Th350, and 32" tires and 3.08 gears got considerably less. I don't think I ever tried to calculate it because I knew the odometer was off due to the larger tires.

68 TT · 08-07-2010, 09:57 AM

Quote:

Originally Posted by C10Silverado79

After the carb rebuild, I think I've finally got all the vacuum leaks plugged and the timing adjusted as good as I'll probably get it. Ran to Pittsburgh an back pulling a small utility trailer, today to take some furniture out to my son's new apartment. 420 round trip mostly highway. The truck is running real smooth now and the trip average was 14.3 MPG. I ran mostly between 60-65 but the GPS said I got up to 75 at least once. The best I used to get was 10 MPG so I'm pleased with the improvement. I have a 350 w/ Q-Jet 4bbl and a TH350 trans. (no idea what the rear ratio is)

Glad you got it figured out. You get twice the gas mileage I do with my 78 K20. Most of my mileage problem is due to the 5.13 gears and no overdrive though.

primrrd · 08-07-2010, 10:33 AM

has anyone got one of those gear vendor under/overdrive units?
I wonder what they would do to help MPG?

As it sounds, Im not sure that the expense of going to a 700r4 would be worth the trouble...

BigRed76 · 08-08-2010, 10:23 PM

Quote:

Originally Posted by Rpratt

I have a one ton dually 4x4 with a 6.2 turbo. I got 19.6 and 19.1 from the last two tanks of fuel.
I have been planning on doing a cummins swap, but I really like this engine for the mileage.

What year?

Rpratt · 08-08-2010, 11:18 PM

Quote:

Originally Posted by BigRed76

What year?

1987

08-01-2010, 10:59 PM	#1
C10Silverado79 Registered User Join Date: Feb 2010 Location: York, PA Posts: 180	Pleased with MPG results. After the carb rebuild, I think I've finally got all the vacuum leaks plugged and the timing adjusted as good as I'll probably get it. Ran to Pittsburgh an back pulling a small utility trailer, today to take some furniture out to my son's new apartment. 420 round trip mostly highway. The truck is running real smooth now and the trip average was 14.3 MPG. I ran mostly between 60-65 but the GPS said I got up to 75 at least once. The best I used to get was 10 MPG so I'm pleased with the improvement. I have a 350 w/ Q-Jet 4bbl and a TH350 trans. (no idea what the rear ratio is) __________________ 1979 C10 Silverado 1998 Camry 5spd 2005 Harley ElectraGlide

08-06-2010, 11:23 PM	#2
84c10tony Registered User Join Date: Feb 2010 Location: victorville, ca Posts: 10	Re: Pleased with MPG results. Beats my 13mpg 65-70 mph with a 305 and 700r4, and no trailer lol. __________________ If you wake up breathing, the rest is fun, fixable, workable or just doesn't matter. 84 c10 stepside sb, 5.0, a/t, 4x2, needing help.

08-07-2010, 12:02 AM	#3
iroc12valve Registered User Join Date: Jun 2010 Location: niagara, ontario Posts: 109	Re: Pleased with MPG results. beats my 10 mpg's with a new F150 in the 5 years/230,000 ive never gotten better than 14 Mpg and it runs so smooth you cant even hear it, my old 89 camaro got 27 MPG Average as high as 34 one time all hand calculated, ran kinda rough even with a new motor, smelled like an old chevy and had very good power.... Gotta love Emissions (B.S.) __________________ 1991 V3500 350TBI/4l80/205 D60/14bff - Crew long 1987 IrocZ-28 525 horse/567 Lb Tq 383 1976 K30 on 39.5s One wheel drive thanks to a np203 and some K5's lol

08-07-2010, 07:25 AM	#4
Rpratt Registered User Join Date: Mar 2010 Location: Grand Rapids Mi Posts: 47	Re: Pleased with MPG results. I have a one ton dually 4x4 with a 6.2 turbo. I got 19.6 and 19.1 from the last two tanks of fuel. I have been planning on doing a cummins swap, but I really like this engine for the mileage.

08-07-2010, 07:39 AM	#5
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	Re: Pleased with MPG results. My 87 GMC with a 5.0 TBI and 700R4 got 16mpg in town, however my 82 Chevy with carb'd 350, Th350, and 32" tires and 3.08 gears got considerably less. I don't think I ever tried to calculate it because I knew the odometer was off due to the larger tires. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

08-07-2010, 10:33 AM	#7
primrrd Registered User Join Date: Jun 2010 Location: houston, tx Posts: 323	Re: Pleased with MPG results. has anyone got one of those gear vendor under/overdrive units? I wonder what they would do to help MPG? As it sounds, Im not sure that the expense of going to a 700r4 would be worth the trouble...



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