My experience has been different. My son's 5.7 with trick turbo and my 6.0 with radix have about 12" of vacuum at cruise. My truck actually gets a little better mileage even though I have a bigger cam and more cubes. I suspect his compression ratio is less than mine and his truck is also quite a bit heavier. I really can't see MPG as a deciding factor in choosing one of these systems. Either will do a good job (relatively) if set up right. Add a turbo to a stock truck and check the MPG. Take it off and add a radix. I'd bet it wouldn't be 1/2 mpg difference. Once you start jacking the motor up, things can change. It all depends on the setup.

 

At 65mph just cruising slightly into boost you will see a gain. I got almost 2mpg better that way. Any faster or more boost your gain becomes a loss.

 

Ive had my truck turboed for over two years now. And with my driving habits ive never seen better than 14 MPG in town it never sees the highway so i cant help you out there its not my dd either. In two years ive only put 6k miles on the truck.

 

With the bypass open on a Radix the load on the engine is extremey minimal whereas the turbo is always a restriction in the exhaust

 

I lost 1~1.5 mpg hwy after my last mod, the Radix. Went from 18 mpg with all mods in sig. (accept Radix) to 16.5~17 hwy cruising after Radix install. I didn't add the Radix for mpg concerns but the trade off in added power more than makes up for the drop in fuel economy.

 

With the bypass open you are circulating the air while spinning the inertial load of the rotors. Say you have a backpressure of 5,10, or 15psi at low load levels with a turbo, this is overcome by 100+psi exhaust pressure exiting the cylinder. You loose some in both cases, but once you start spinning the turbo it is able to make up the loss before you go into boost.

I'm not going to say one is better than the other, I just *think* the turbo has a better shot at mpg out of boost. Don't choose one or the other based on this. Ride in both if you have the chance and pick based on power delivery and make sure you will be able to meet your goals.

 

My average mileage never really varied much after the turbo. I have gotten about 12.5 to 13 mpusg since the truck was new.

 

I can see what yall saying. I love turbo bec can adjust more boost what I want Hey Trever1t Is your sc radix correct. IS there anywhere I can see or explain me to compare radix, procharged, Magnacharger, kennel bell or whipple. I am curious which is better for supercharged? I thought its procharged or kennel bell (KB have 2.8 bored) not sure.

 

lol, don't go all tech on me

 

Sorry about that