COMPLETE LS SWAP MPG

20Grand

20Grand

Apprentice
Mar 16, 2018
59
10
8
#1
We took a trip from Omaha to Las Vegas a few days ago and averaged almost 22 mpg going 75-80. The swap is a 5.3 from an 05 Silverado. That includes running AC full time and mountain passes. The last part of the trip from Salina, Ut to Vegas was right above 19, which my average speed was around 85-87 and some very steep inclines coming out of Salina. I thought this was pretty excellent. I’m running 20” Camaro wheels with low rear end gears and a good tune. New O2 sensors as well.
 
69hurstolds

69hurstolds

G-Body Guru
Jan 2, 2006
691
429
63
#2
Sounds great. All that plus a little better power than stock as well? Can't beat it with a stick. Well, you could, but the body work bill would be astronomical to fix.
 
street sweeper

street sweeper

Greasemonkey
Jun 12, 2017
174
163
43
Central Indiana
#3
im assuming a 4l60e and a factory highway gear?
 
CaliWagon83

CaliWagon83

Royal Smart Person
Supporting Member
Nov 12, 2017
1,373
698
113
Orange County, CA
#4
I’d be very happy with that, especially considering the difference in power over stock. I read somewhere that a ‘55 Chevy with a 6.2L E-Rod swap got about 23 mpg highway.

I would be thrilled with that level of FE in my wagon, considering it probably gets less than that with the wheezy stock V-6. What rear end ratio are you running?
 
20Grand

20Grand

Apprentice
Mar 16, 2018
59
10
8
#5
Yes, 4l60e with stock 2.73s I believe is what it is. I drove 2005+ Cad STS’s and even their v-6 couldn’t do that. The best I ever got with those 8s were 18 and I’d have to do 65 to get it. The only thing I’d like to do is increase the gears. I overheated going up a mountain in Utah and I wonder if that had anything to do with it. But, posted this so people knew what was going on. I’m a stickler for efficiency and mpg.
 
CaliWagon83

CaliWagon83

Royal Smart Person
Supporting Member
Nov 12, 2017
1,373
698
113
Orange County, CA
#6
Out of curiosity, what were your freeway RPMs at 75-80?
 
20Grand

20Grand

Apprentice
Mar 16, 2018
59
10
8
#7
Out of curiosity, what were your freeway RPMs at 75-80?
I wish I knew but I don’t have an rpm gauge. It feels low, and I’d say somewhere around 1800. I don’t have much power in 5th.
 
O

oldsmobile joe

G-Body Guru
Nov 12, 2015
822
522
93
mpls
#9
if you tell us the tire size and rear end gear ratio, transmission type and does it have lock-up converter. we can tell you the rest
 
20Grand

20Grand

Apprentice
Mar 16, 2018
59
10
8
#10
Tell me the rest about what? 245/35/20, 273 and 4l60e. Not sure on converter. All stock 05 Silverado.
if you tell us the tire size and rear end gear ratio, transmission type and does it have lock-up converter. we can tell you the rest
 

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