My First 6.0 with a 228/230 cam averaged about 17-18mpg. I never really babied it around to try and get any better mileage. The 404 high compression motor averaged about 9mpg on E85...LOL
My First 6.0 with a 228/230 cam averaged about 17-18mpg. I never really babied it around to try and get any better mileage. The 404 high compression motor averaged about 9mpg on E85...LOL
E85 makes a big difference for one... and the 404 had a donkey dick cam and stall which I KNOW you never babied.Originally Posted by DBRODS
1969 Chevy RCLB C10 350/TH400 SOLD
2007 Chevy RCSB 4.8 4x4 LS SOLD
2008 Chevy RCSB 5.3 4x4 LT SOLD
2010 Chevy CCSB 6.2 4x4 LT SOLD
2005 GMC CCLB DRW 6.6 Duramax 4x4 191,000 and counting
2013 FORD CCSB F350 6.7 Powerstroke 4x4
Okay, this would be my daily driver. If I do a conversion then I want to keep the 3.42 gear in there. I drive alot easier than when I was younger. Not old man driving but not to the floor everywhere I go either. Just in the middle I would say. I will stay with an auto trans. After I origianlly posted this I got to thinking. Doesn't the true LS engines get better mileage and the 4.8,5.3,6.0 truck engines. I have read (whether true or not) a couple of conversions where getting low to mid 20's mpg. This may have been in a 2wd thought. I can't remember.
Now on my 03 2500HD Crewcab 4x4 with the 6.0l I got around 14mpg when first bought it with 80,000 on the clock. Now it has around 140,000 and gets worse mileage. I am sure a tune up would do some good but the initial mileage was around 14. I was told to loose the fatory muffler and open it up with a good one but have yet to that. I am told the factory muffler restricts a ton.
I am not wanting unrealistic mpg just trying to get a feel on what I should be looking at if I start looking for an engine/drivetrain. Would it be better to try and find something out of a car verse a truck?
Car vs truck, NO. There is no difference. It's all in the setup. Devin (Frenchy) on here gets 26mpg with his 5.3/5speed setup. There are multiple people with conversions getting 20-22 highway. Hell, I've gotten 20 in my 6000lb crew cab more than once.
1969 Chevy RCLB C10 350/TH400 SOLD
2007 Chevy RCSB 4.8 4x4 LS SOLD
2008 Chevy RCSB 5.3 4x4 LT SOLD
2010 Chevy CCSB 6.2 4x4 LT SOLD
2005 GMC CCLB DRW 6.6 Duramax 4x4 191,000 and counting
2013 FORD CCSB F350 6.7 Powerstroke 4x4
Have basically the same setup but mine is a 5.7, I get about the same gas mileage on the highway. It has nothing to do with the size of the engine, the bigger the engine the less it has to work to maintain speed and get up to speed. My LS6 is WAY better on fuel than my 4.3 V6! Don't have exact numbers but I'd say between 24 and 27mpg.
2000 Chevy Silverado RCSB LS6 5 speed, LS6 short block, 317 heads, LS6 intake, Lunati 220/224 .575/.575 112LSA cam, Edelbrock Headers, CTS-V accessory drive, Nelson Performance Custom Tune.
I just got done a few weeks ago doing an ls1 swap on my 89 obs truck with the same gear ratio with a nelson tune and i still average about 18you when my foots not through the floor. Either way going from a tbi fo fuel injection is alot better on gas. Ls1 is a little bit harder to find but its great power and decent mileage
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