How Many Miles Per Tank?

[Firebirdjones]

Originally Posted by C-10 simplex

Not good. i get about 294-302 per tank.

As far as the 700r, it depends on what your rear axle ratio is.

i think the only way to get over 20 in trucks like these are, in order or preference:

1) move down on cubes----4.3 v-6. This may reduce towing/hauling ability.

2) 6.2 diesel

3) A new LS with cylinder deactivation. A regular LS should do it too.

I've done it with carbed 350's, (over 20 mpg) with an overdrive and sharply tuned. So it's doable but most people won't or can't spend the time to dial one in properly. Shucks I get 17 mpg out of my 70 formula with a 434 cubed pontiac, a carb, 400 turbo, and 3.31 gears. An overdrive in that would put it right at 20 mpg piece of cake.

I get 22 mpg with the 6.0 LQ4 (LS engine basically) swapped into my 72 4x4 blazer, 4L60 and 3.73's on 33" tires, and no cylinder deactivation (that's cheating ). Alot of people told me mileage wasn't going to be it's strong suit either, but it holds it's own against any new V8 SUV. A 6.0 is just 364 cubes, it's not a big engine by any means.

There is so much more to mileage than the engine choice. It's really best to concentrate on the little things before spending money changing the total package. So many things that rob power and MPG. Tires, wheels, the weight of the tires and wheels, tread patterns, the tune, the weight of the vehicle, driveshaft, engine driven fans, oil viscosity, gas quality, correct gear choices, transmission choices. You can go on and on, and find at least 2-3 mpg if you are willing to spend the time and money on simple things first.

If I can get 14 mpg out of my 79 1 ton with a 502/400 turbo and 3.73's then anyone can at least do it with a 350. I'm expecting to pick up another 2-3 mpg with the gearvendor install.

[jon75]

Originally Posted by Firebirdjones

I get 22 mpg with the 6.0 LQ4 (LS engine basically) swapped into my 72 4x4 blazer, 4L60 and 3.73's on 33" tires, and no cylinder deactivation (that's cheating ). Alot of people told me mileage wasn't going to be it's strong suit either, but it holds it's own against any new V8 SUV. A 6.0 is just 364 cubes, it's not a big engine by any means.

There is so much more to mileage than the engine choice. It's really best to concentrate on the little things before spending money changing the total package. So many things that rob power and MPG. Tires, wheels, the weight of the tires and wheels, tread patterns, the tune, the weight of the vehicle, driveshaft, engine driven fans, oil viscosity, gas quality, correct gear choices, transmission choices. You can go on and on, and find at least 2-3 mpg if you are willing to spend the time and money on simple things first.

If I can get 14 mpg out of my 79 1 ton with a 502/400 turbo and 3.73's then anyone can at least do it with a 350. I'm expecting to pick up another 2-3 mpg with the gearvendor install.

I find your claims of 22mpg interesting with a 6.0 in a blazer, especially with the setup you are running. I worked for GM for a number of years and was there when the LQ engines were released. They have never been efficient engines, they are made for torque. But if that claim IS true, please write GM and let them know how you did it!

I do agree that there is a lot more to MPG than the engine so I was glad to hear you say that.

And I have a 350 in my truck. Without changing the front and rear gears to a 2.89 or something, there's no way I will achieve the economy you are claiming in your truck with the 502 (I have 4.11 gears and an SM465 tranny). Maybe one thing you are missing in your list is load % on the engine while cruising.

I'm really not trying to start anything, but if you could clarify how in the heck you did achieve these numbers, please enlighten us! Share the wealth man!