Carb'd 6.0 MPG
 

Sorry with another MPG question. Ive been considering going the carb route with a 6.0. What kind of gas mileage are you guys getting with a carb vs an efi setup?

I will be running a 6.0 with a decent cam, 6 speed manual and 4.10s in the rear if the MPG is reasonable.

I should know all of the above sometime in the near future. Setup the same as you but 3.89 gears. I think it all depends on how often you want to tune on it

Mine has been shitty lately mostly because of my converter. Which is a 3400 stall. If I'm driving under my stall speed then it's wasting energy through the converter. Also it revs at 3500 at 70mph. That's with a 27"tire and 373's with a th350.

If "decent cam" = less than 226 or so, with the 6-speed in a Chevelle, 750 carb, I would ball-park it at 16-17 mpg highway, maybe more if you run a A/F gauge to fine-tune your carb

Does anyone have any actual proven numbers and not ballpark figures. I dont want to put this engine together and find that it gets a couple mpg's better than my 454.

There have been multiple threads on this.

I'm running a 6.0L LS2 with the stock LS2 cam (i.e. LS6), 750 DP, 2500# car, TKO 5 speed, 3.54 rear and 25" tire. I turn about 2200 RPM at highway speeds and regularly get 25 mpg. In fact, my conversion is the economy car of the family.

Most guys with heavier/larger cars are pulling down 20's if they have a proper overdrive. Gearing is key in this case, not the induction method.

....and the mass of the vehicle

T56 Trans, 27" tall tire, 4.30 gears, trex cam, I get bottom 20s driving normal.

Wow, thats pretty impressive. What RPM do you run at.......................say 60 mph in 6th gear if I may ask. Again, impressive results for a carbed application IMHO. Eric L

Have it dialed in to 14.7-15.0 AFR at cruise speed, 2000 rpm in 6th is 77 mph, lol.

With 4.30 thats crazy good.

Double over drive baby!

with my old combo 3400 stall th400 3.89 28" tires on E85 i got 10 at 70ish :)

E85 is not for economy, lol.

No not at all.... Hell I was pretty happy with 10 LOL

Not sure but my 78 Malibu is easily getting twice the mileage as my 81 505 BBC powered does. I have gotten 28 passes out of a tank where the 81 gets around 8. And I still have 1/4 tank.