estimated mpg 6.0 chevelle
03-24-2012, 06:08 PM
#1
Launching!
Thread Starter
estimated mpg 6.0 chevelle So I've decided to go with a 6.0 instead of a 5.3 because I don't have the skill to fab up a turbo and I would like to keep the swap cost to a minimum.
I currently have a 461 with a th350 and 4.11 gears. As you can imagine, its not very street friendly and the gas mileage is god awful at 8mpg or less.
My plans are to sell or part out the BBC, sell the tranny, and use the money to put together a 6.0, higher gears in the 3.42 range and an overdrive auto or manual tranny.
What kind of mpg could I expect with the above combo?
I currently have a 461 with a th350 and 4.11 gears. As you can imagine, its not very street friendly and the gas mileage is god awful at 8mpg or less.
My plans are to sell or part out the BBC, sell the tranny, and use the money to put together a 6.0, higher gears in the 3.42 range and an overdrive auto or manual tranny.
What kind of mpg could I expect with the above combo?
03-24-2012, 06:53 PM
#3
TECH Apprentice
iTrader: (12)
Join Date: Oct 2011
Location: Denton Md
Posts: 381
Likes: 0
Received 0 Likes
on
0 Posts
I say keep the 4.11s and get a t56. That will be a fun ride. Im hoping to be up and running in about a few weeks, Im doing a 6.0 swap with th400 with 3.55s im waiting to see what that combo will do.
Trending Topics
03-25-2012, 07:27 AM
#8
The 22mpg is a combo of city and hiway as my DD.
The 6.0 LQ9, Richmond 0.76 OD, 3.08 rear (2.34 overall) runs at 2000 rpm on the highway. Best of 26mpg. You'll be turning a few less rpm with the T56/4.11, that helps, but the chevelle will be a couple hundred pounds more and less aerodynamic. So I'm thinking low to mid 20s is pretty realistic if your foot isn't too heavy.
I dont think a 3.42 rear is practical in a heavy vehicle using a 0.5 OD, so you gotta ask yourself if the cost of a 3.72 swap is worth a couple percent increase in milage. My experience is in my old camaro is that even the 30% rpm change with OD would only increase milage about 10% on hiway. A 10% change in the rear would be considerably less and probably negligable in city driving.
The 6.0 LQ9, Richmond 0.76 OD, 3.08 rear (2.34 overall) runs at 2000 rpm on the highway. Best of 26mpg. You'll be turning a few less rpm with the T56/4.11, that helps, but the chevelle will be a couple hundred pounds more and less aerodynamic. So I'm thinking low to mid 20s is pretty realistic if your foot isn't too heavy.
I dont think a 3.42 rear is practical in a heavy vehicle using a 0.5 OD, so you gotta ask yourself if the cost of a 3.72 swap is worth a couple percent increase in milage. My experience is in my old camaro is that even the 30% rpm change with OD would only increase milage about 10% on hiway. A 10% change in the rear would be considerably less and probably negligable in city driving.
03-25-2012, 09:47 AM
#9
03-25-2012, 11:24 AM
#10
Launching!
Thread Starter
Wow I guess I am wrong. I think im just cynical towards my 4.11s haha. Im going to look into what it takes to swap in a T56 as I have an automatic right now. Thanks for the ideas!
03-25-2012, 01:54 PM
#11
Launching!
Join Date: Jan 2011
Location: Arizona
Posts: 200
Likes: 0
Received 0 Likes
on
0 Posts
maybe concentrate on the rest of the swap and try the 4.11's first. at least you can change them later without disturbing anything else. But let us know how the mileage works out both ways.
03-25-2012, 03:00 PM
#12
The 22mpg is a combo of city and hiway as my DD.
The 6.0 LQ9, Richmond 0.76 OD, 3.08 rear (2.34 overall) runs at 2000 rpm on the highway. Best of 26mpg. You'll be turning a few less rpm with the T56/4.11, that helps, but the chevelle will be a couple hundred pounds more and less aerodynamic. So I'm thinking low to mid 20s is pretty realistic if your foot isn't too heavy.
I dont think a 3.42 rear is practical in a heavy vehicle using a 0.5 OD, so you gotta ask yourself if the cost of a 3.72 swap is worth a couple percent increase in milage. My experience is in my old camaro is that even the 30% rpm change with OD would only increase milage about 10% on hiway. A 10% change in the rear would be considerably less and probably negligable in city driving.
The 6.0 LQ9, Richmond 0.76 OD, 3.08 rear (2.34 overall) runs at 2000 rpm on the highway. Best of 26mpg. You'll be turning a few less rpm with the T56/4.11, that helps, but the chevelle will be a couple hundred pounds more and less aerodynamic. So I'm thinking low to mid 20s is pretty realistic if your foot isn't too heavy.
I dont think a 3.42 rear is practical in a heavy vehicle using a 0.5 OD, so you gotta ask yourself if the cost of a 3.72 swap is worth a couple percent increase in milage. My experience is in my old camaro is that even the 30% rpm change with OD would only increase milage about 10% on hiway. A 10% change in the rear would be considerably less and probably negligable in city driving.
I tend to agree. I have 3.73 gears w/15 in 235/60/15 442 wheel/tires on my cutlass. I could only use the 6th gear for highway cruising w/my LT1/t56 combo. When I had my T56 built I had TDP put in the higher number 5th/6th gear combo (forget but 6th gear closer to .6). Hoping to enjoy 6th gear more w/my LSx setup.
