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Old 02-22-2012, 12:39 AM   #1
CROWN
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How many MPG is your LSX getting??

Hey guys! I would like to see the setups yall are running and what kind of mpg you're getting out of them?? Ill be running a 4xx ci lsx with a 4l80 and havent decided on what gear yet. Post up!!
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Old 02-22-2012, 12:49 AM   #2
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Re: How many MPG is your LSX getting??

I get 14 mixed. But not factory efi. Its a FAST EZ-EFI 85 4x4 burb 33 inch tires and that was a 700r4 with 3.73 gears. May not be exactly what your looking to hear but i bet mine is one of the lowest. Got 7 with out of tune carb....found out quick i suck at carb tuning.
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Old 02-22-2012, 12:53 AM   #3
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Re: How many MPG is your LSX getting??

Exactly what i wanted to hear! Im just trying to see what engine/trans/gear is of everyones setup. Your also in tyler too...hmm im in longview!!
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Old 02-22-2012, 12:55 AM   #4
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Re: How many MPG is your LSX getting??

I have heard 20s with factory efi. That is what the wifes truck will be reciving one day. A 5.3 with factory efi. I drive by longview almost everyday. Hate to drive threw it. Seems it does not matter what time of day there is always traffic.
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Old 02-22-2012, 12:25 PM   #5
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Re: How many MPG is your LSX getting??

I get about 14.5 mostly in the city. I have only taken one long-ish trip in my truck and I got about 19.5 on the highway, all highway.

I didnt put the specs in there...I am currently running 3.08 with a 28" tire ( soon to be 3.73) 4.8/4L60E
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Old 02-22-2012, 12:32 PM   #6
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Re: How many MPG is your LSX getting??

5.3/4L60E in a '66 C-10 w/3.50 gear and 28" tire. I just drove it on a 250 mile trip across the desert at 65 MPH with a little tailwind and got 21 MPG.
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Old 02-22-2012, 03:01 PM   #7
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Re: How many MPG is your LSX getting??

4.8/4L80E city driving about 15. Haven't had her on the highway much.
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Old 02-22-2012, 06:31 PM   #8
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Re: How many MPG is your LSX getting??

Only had mine together for a short while. 5.3/4L60E,3.42 gear,28" tire 87 short bed 4X2. The last 2 tanks got 16-non highway driving. Seems like the computer is learning as it goes and milage getting better.
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Old 02-23-2012, 10:30 PM   #9
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Re: How many MPG is your LSX getting??

I have a 6.0 LS2 with T56 and 3.73 posi. So 70 mph is 1700 rpm in sixth. Stock tune from a 2005 SSR with cats, and SSR type exhaust. Really makes a good running reliable daily driver.

I am getting an honest 17 mpg over about a year of driving back and forth to work. (I check every tank)

I say honest because it was 20 mpg before I calibrated the odometer. Actually I now use the calibrated VSS signal and the ECM distance calculation read by my scan gauge. (calibrated with GPS over a long distance).

I am a little disappointed. My Vette with essentially the same engine and exactly the same gearing gets an honest 21 mpg over the same routes.

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Old 02-23-2012, 11:00 PM   #10
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Re: How many MPG is your LSX getting??

Bricks.aren't real aerodynamic ...
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Old 02-24-2012, 09:41 AM   #11
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Re: How many MPG is your LSX getting??

^^^and quite a bit heavier.
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Old 02-24-2012, 11:58 AM   #12
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Re: How many MPG is your LSX getting??

You mean I won't get in the 20's with my CCSB 6.0/4l80e cammed, heads, and heavy foot? That's it, I'm stopping my build, and buying a smart car!
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Old 03-03-2012, 07:17 PM   #13
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Re: How many MPG is your LSX getting??

I get 16 around town 3:42 gear and a 26 inch tire. The CCSB weighs in at 5000 pounds.
Lots better than the 454 it was getting 6-8 mpg. Jay
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Old 03-04-2012, 07:59 PM   #14
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Re: How many MPG is your LSX getting??

Just looking to make the swap to a GenIII/IV motor. This is important info as fuel will only become more precious with time. With my BBC LS6 450 horse motor, I get about 17 on the hwy albeit with 3.08 gears and a 700R4 OD. I can go almost 300 miles on a stock tank (70CST). Interesting to think that I would not get that much better with a newer motor. No doubt though it would afford me a better rear gear with not much sacrifice in MPG. Thinking of going to a 3.42 LSD.

Also intersting to read that there is not much diff between the 4.8 and 5.3 and about the same diff to the 6.0.
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Old 03-05-2012, 06:50 PM   #15
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Re: How many MPG is your LSX getting??

18-19 on my stocker(02 siverado, 4.8). I run generally 70-72 on the hyway, & figure around 14 in town. The old truck has 3.42 gears. crazyl
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Old 03-05-2012, 07:20 PM   #16
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Re: How many MPG is your LSX getting??

My big cam/ported headed 11-1cr 347 was getting about 11mpg mixed driving with a 4L80E and 3.73's with 30" tire. But the cam was designed to make big power at high rpm. Not really meant for MPG at sub 2,000rpm. Lot's of overlap.

With the new 418ci motor with glide, not too sure, haven't driven it around much.
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Old 04-23-2012, 01:51 AM   #17
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Re: How many MPG is your LSX getting??

my 6.0 4l80e gets about 7 in town,I sure need to get it re tuned I probably double my mileage but when add the 3600 stall it will probably get 7 still
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Old 04-23-2012, 01:13 PM   #18
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Re: How many MPG is your LSX getting??

from 12-18 w/bed full of gear on 3:73's and m/t drag radials.
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Old 04-23-2012, 02:17 PM   #19
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Re: How many MPG is your LSX getting??

if our l33 swap can get mid teens city/mixed and low 20's straight highway. i would be totally stoked. that is what my wagon gets and it is affordable to drive everyday
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Old 04-24-2012, 09:10 AM   #20
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Re: How many MPG is your LSX getting??

Well when I first did the swap about 7 years ago I got around 20ish, that got boring so I added a bigger bummpty cam and gained a lot in sound and power and lost a couple miles per gallon then I got bored again so it is now turbo charged with that same cam. I am still above 15 but had not continued to check it real close. Its a heavy truck of course but sure screams now. I drive it alot and loaded it up this weekend and went camping
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Old 04-24-2012, 10:12 AM   #21
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Re: How many MPG is your LSX getting??

Quote:
Originally Posted by Custom 68 View Post
Well when I first did the swap about 7 years ago I got around 20ish, that got boring so I added a bigger bummpty cam and gained a lot in sound and power and lost a couple miles per gallon then I got bored again so it is now turbo charged with that same cam. I am still above 15 but had not continued to check it real close. Its a heavy truck of course but sure screams now. I drive it alot and loaded it up this weekend and went camping
Do you have a link to a picture of your turbo set up? Is it a single and what size? lbs boost? Blown V8 Gen III/IV sure would be sweet!
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Old 04-24-2012, 02:17 PM   #22
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Re: How many MPG is your LSX getting??

I will get some better photos it seems like most of my projects I just do and dont document too good or do alot of posting on them on here. I know I should but have not been good at that I just seem to work on it when I can afford the time and money. Currently I had gathered parts for a while and in the used stuff I had was a T60 turbo it is too small IMO as it chokes up top however it will spool instantly so it is alot of fun on the street I am intercooled and am only pushing 8 or so psi. Once I can afford a larger turbo I will swap out. I didnt want to go too big since I wanted teh quick spool when I collected the parts it was supposed to be a T67 but once I got it it was smaller. Like I said I can be at full boost in an instand so it is crazy from idle to about 4500 then it chokes some so I dont run it that hard for now. These gen III and IV sure like cams and boost.
I had NOS for a while and that was fun too but this turbo is a neat addition plus I can drive it and not worry too much.
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Old 04-24-2012, 02:42 PM   #23
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Re: How many MPG is your LSX getting??

Quote:
Originally Posted by Custom 68 View Post
I will get some better photos it seems like most of my projects I just do and dont document too good or do alot of posting on them on here. I know I should but have not been good at that I just seem to work on it when I can afford the time and money. Currently I had gathered parts for a while and in the used stuff I had was a T60 turbo it is too small IMO as it chokes up top however it will spool instantly so it is alot of fun on the street I am intercooled and am only pushing 8 or so psi. Once I can afford a larger turbo I will swap out. I didnt want to go too big since I wanted teh quick spool when I collected the parts it was supposed to be a T67 but once I got it it was smaller. Like I said I can be at full boost in an instand so it is crazy from idle to about 4500 then it chokes some so I dont run it that hard for now. These gen III and IV sure like cams and boost.
I had NOS for a while and that was fun too but this turbo is a neat addition plus I can drive it and not worry too much.
IMO, small turbo to these Gen III/IV motors is an excellent addition. They are over built compared to the small blocks and are rock solid. Even a 4.8 would reach 500HP numbers with a single 67mm at about 12-14 lbs. of boost! The stock 5.3 numbers just don't impress me given the excitement I get from my LS6. If I go with a 5.3 it will have to be boosted. (just a matter of time)

I'll friend you so that when it comes time, I can consult you...if you don't mind. I know FI but not too much about boost...parts vendors and such. Pics a definite plus so I can see how you routed the tubing, blow-off, intercooler attachment, etc.
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