What's the secret to retaining good gas mileage in a performance application?

[HotRoddin]

Originally Posted by Vector

I KNOW there are motors out there delivering 400 horsepower, and still get 20mpg on the highway.

There is !!! ??? You're gonna have to show me some "official" specs to get me to buy that one.

There is no question however that the MPG vs HP ratio has vastly improved in the last few years, and it's all about efficiency. The combustion chambers have been designed to burn fuel more efficiently, the fuel/air charge is metered more precicely, there is less friction, everything is lighter, there is a crapper load of little things they have done that all adds up to better fuel economy for the HP produced. The car factories all have huge Engineering staffs working on that stuff all the time. I don't think you can pin it down to any one or two things, it's a combination of lots of things.

Rod

[GhettoPop]

Originally Posted by Vector

I KNOW there are motors out there delivering 400 horsepower, and still get 20mpg on the highway.

Well, i doubt any fox body is doing that, but the new dodge charger/magnum/300 srt8's w/ the 6.1 425 hp hemi might get close to 20mpg highway, but keep in mind these engines only run w/ 4 cylinders on the highway to reduce fuel consumption.

I may be off your original question though. Do you have a specific stang your looking to get better MPG with? need more info

[Vector]

Well, I don't have a stang, I've got a truck with the 302. And down the line I'm looking at having heads/cam/intake/exhaust but I was wondering if it's too much to hope for that a good combination can retain decent mileage with 'light driving'. I get about 15-17mpg city 20 highway. Is it too much to hope that I can keep it like that? With more power available and torque won't the engine have an easier time of it anyway?

Also the o2 sensor, will it hurt mileage to use long-tube headers? Thanks!

Originally Posted by Vector

Well, I don't have a stang, I've got a truck with the 302. And down the line I'm looking at having heads/cam/intake/exhaust but I was wondering if it's too much to hope for that a good combination can retain decent mileage with 'light driving'. I get about 15-17mpg city 20 highway. Is it too much to hope that I can keep it like that? With more power available and torque won't the engine have an easier time of it anyway?

Also the o2 sensor, will it hurt mileage to use long-tube headers? Thanks!

I doubt you'll be able to retain your current 15-17mpg with aftermarket heads, cam & intake. I bet you'll be able to stay close to those #s though. Maybe somewhere between 13-16mpg with a well tuned motor & a light foot. When you're into modifying cars or trucks to go faster, and produce more power...getting good gas mileage just isn't part of the deal really. Unfortunately you can't have your cake & eat it too.
As for the oxygen sensor...the header company might be able to help you on where to tap into the header, or the exhaust tubing and thread in the O2 sensor. I'm pretty sure as long as it's within 18" from the exit of one of the headers...you're truck's (or car) computer can still adjust accordingly. I'd do some research with header companies first. Look into the reputable ones and talk to their techline...if they have one.