sound dumb, but what if someone built a motor for...

[carbed87]

gas milage! like mabey a motor with like 250hp, but with like 30mpg.

is this possible, could doing things like port the heads, but just enough to free restriction of airflow, and freeing up the exaust just enough to get the air moving better actually end up helping the gas milage.

i guess the point would be to free the motor of restriction, while being careful not to cross the line to where it trades it's gas milage potential to performance.

im not trying to sound stupid or anything, but wouldn't it be cool to have a rather modest 13 second car that at the same time gets like 30+

let me know what you think of this.

 

[poneypower89]

yea, most mid-level performance imports already do that.

 

[carbed87]

ouch, i can see where this is going... better put my flamesuit on.

 

[poneypower89]

yep... sorry bro... sometimes you just walk into to situations like this.

 

[MyBad70]

:damnit:

 

[Aliate X]

Honestly, if you want gas milage and power you shouldnt look towards a V8, smaller forced induction motors do this much better than V8's like STi's

 

[dragnazz5.0]

yeah, its called building a motor with better volumetric efficiency....it just so happens that when you build a motor to be more effecient it also makes more power.

 

[Aliate X]

yeah, its called building a motor with better volumetric efficiency....it just so happens that when you build a motor to be more effecient it also makes more power.

More power = more air and more fuel. More fuel is less gas milage.

You cant have something for nothing.

On the other hand, after my h/c/i swap, my gas milage hasnt changed much but the car is a whole new animal.

 

[CRASH7772]

Stock 5 speed 87-93 5.0's (notchbacks and SD stangs would be best) get close to 30MPG highway and run low to mid 14's when healthy. If you lighten it up, keep the 2.73's and free up some HP with pullies, exhaust, and filter with a good dyno tune I don't see why you couldn't dip into the 13's with a good pass and get close to if not 30MPG with it. If you have the low end torque to pull the gear this will net some good ET's with 2.73's and keep good fuel mileage. I was running low 14's and getting 24-27 for MPG on a tank of all around driving prior to me messing with the gears and engine witout a dyno tune.

I have gotten 31 MPG with my 220HP Mazda 6 and that's a higher reving 6cyl which has no balls down low IMO.

 

[Aaron]

View attachment 462461

 

[795.0pacecar]

My car makes 260hp at the wheels (probably a bit more now since I've done some garage tuning) and I consistently get between 21 and 25mpg. Not bad if you ask me.

 

[dragnazz5.0]

More power = more air and more fuel. More fuel is less gas milage.

You cant have something for nothing.

On the other hand, after my h/c/i swap, my gas milage hasnt changed much but the car is a whole new animal.

i wasnt necessarily saying build the car to make more power and you get better gas mileage. i was saying that the gas mileage and effeciency of a motor depend entirely on its capability to change heat into motion (thermal efficiency). most engines run at about 30% thermal efficiency. the volumetric efficiency i was talking about has a lot to do with thermal efficiency. you cannot build a gasoline engine that runs at 100% efficiency...its impossible. but the closer you get to 100% the better the gas mileage and you just happened to be making more power.

i know what youre saying that more power equals more fuel and air...which is true. but if you take a motor that can run at 60% efficiency and a motor that can only run a 30% efficiency than the previous motor will get better mileage and make more power simply because it is converting more heat into more mechanical motion (power).

 

[ryan218]

no in the 5.0 magazine there is a fox in there that has 800hp and 20MPG

 

[bryce93lx]

You can check to see how much gas it burns??? i always figured it just burned all i put it, if you want to go fast an get good mileage buy a motorcycle

 

[carbed87]

lol, i wasn't going to do it, just a stupid idea i had. sorry

 

[poneypower89]

well.. to help you our from get'n too flamed here...

An american company far exceeds your wish list here...


Yep.. the NEW zo6 corvette.. 500+ hp and 30 mpg on the HWY.. and this is with a PUSHROD

Oh yea, think I read somewhere they run something in the 11's as far the 1/4 mile