Economy and power from a H/C/I combo

[dstang01]

Ive been wondering about this for awhile. Because the stock 5.0 intake and heads are so restrictive, and the cam isnt optimized, can changing your top end actually help gas mileage as well as power if you choose a more mild combo? It makes sense that with more efficient parts, the engine should run more efficiently and get better economy and power. For example the ls1 is a pushrod engine like the 5.0 and it also has .7L more displacement, yet it makes much more power and gets better mileage as well. I know new technology has to do with it, but arent re really just retrofitting new technology to our motors when we modify? What do you guys think?

 

[FastDriver]

Increased compression ratio is a big difference between the LS1 and the 5.0. A leaner tune, increased CR, and a cam optimized for gas mileage and free flowing heads, intake, maf, and TB would go a long way toward increasing gas mileage. I doubt there's any reason why you couldn't get 30mpg if you tried to do it with a 5.0.

You still won't have the low Cd of the vette, and Camaro, so don't expect to get good gas mileage at 80mph. Also, consider that the LS1s CR is so high that it has to run premium. 20 cents per gallon makes a car that's getting 28 mpg about the same cost to run as a 25 mpg car that runs on the cheap stuff.

And, the money it takes to build a combo that's fuel efficient will never pay for itself. Lets say you go from 20mpg to 26mpg in your mustang (a realistic difference if you go with a mild cam. Whereas $1,000 for aluminum heads, $450 for intake, $250 cam, $200 for injectors, $200 for MAF, $200 for throttle body, $80 for pullies, $100 to install (doing it yourself), and $500 for a dyno tune adds up to $2,900. At $2.30/gal, you'd have to go 109,275 miles (check my math if you like) driving lightly (yeah right) to make up the difference assuming you wouldn't do anything smart with your money like investing if you didn't spend it on your car.

Chris

 

[mustangramair]

When i changed my H/C/I, my mileage stayed about the same. I average about 18 mpg. I was happy, i thought my mileage would drop.

 

[CRASH7772]

The GM's also run a 6 speed transmission with a .50 6th gear compared to the .68 of most 5 speed 5.0's. I do know of a local that runs 260RWHP and gets mid 20's MPG and runs high 12's on street tires with 3.73 gears. Of course his family member runs a dyno shop and has it dialed in.

 

[bubba-dough]

There are a lot of variables on that. Btw aren't LS1's a 6.0? But those cars have thousands of hours of design and engineering to achieve those power levels and mileage. And when they do those gas mileage test how are they doin them? Its more than likely a controlled environment and on a dyno or some type of rollers where they are granny drivin it. Not out here in the real world where Johnny is gonna be punchin it from stop light to stoplight.

Aftermarkets parts for our cars are just to go fast.

 

[90_Red_LX]

There are a lot of variables on that. Btw aren't LS1's a 6.0? But those cars have thousands of hours of design and engineering to achieve those power levels and mileage. And when they do those gas mileage test how are they doin them? Its more than likely a controlled environment and on a dyno or some type of rollers where they are granny drivin it. Not out here in the real world where Johnny is gonna be punchin it from stop light to stoplight.

Aftermarkets parts for our cars are just to go fast.

Ls1 is a 5.7 which is no longer in production idt, and the ls2 is it's replacement. The ls2 is the 6.0.