http://www.usatoday.com/money/autos/environment/2007-06-25-cylinder-usat_N.htm?csp=34

sample quote

All those automakers already sell vehicles with cylinder cutoff. In most cases, it is said to boost mileage about 6%. While an impressive percentage, it typically works out to just 1 mile per gallon or so. At Ford Motor, "We have it, we can use it, but the real-world fuel-economy benefit hasn't been there," says spokesman Nicholas Twork. "Not to say it won't be some day, but for the time being," Ford's not planning cylinder cutoff.

 

at least one company realizes it...

 

Just read in Road and Track that DC is thinking about going to 3 cylinder MDS on their cars.

 

I think the MDS helps my 4x2 hemi. The 30minute commute to my job is on a slight incline. On the way there I average 19mpg. On the way back, if I keep it at 60, I can get almost 24mpg! (If I go up to 70, the milage goes down to 19.)

The MDS seems to really help save gas when you are coasting.

 

1 mpg gains might not seem like much but when you have gone from 17 mph to 20 mpg one mpg at a time it adds up. When you look at actual cost savings you're looking like you are getting about4 gallons of gas for free each tank full of gas if you use 26 gallons (standard ram tank size). That's literally $12 a tank of gas I can save.

 

Why not have injecters that can increase or decrase flue flow per cylinder upon demand instead of shutting off the spark to 4 cylinders.

If you could make all eight cylinders more efficent when you don't need the power, this would = out to the same amount of flue used to run four non mds cylinders vers four mds cylinders, and I'm positive the inturnal engine components will last longer.

I'm not educated on the mds princeapals, but to have four pistons draging when four are firing don't make any sense to me, esp in a truck that is having four cylinders fire to keeps a 5000+ truck coasting.

Or better yet have a extra intake and ex valve that don't open or close under light load, but open under high load, ie variable valve timming.

Did I just over complicate the issue?

 

LMAO

I drive 80 miles a day in a hemi Quad cab. They wanna GIVE me 1 MPG with no tradeoffs..... I'LL FREAKIN TAKE IT.

pokerman

 

I just want my non-MDS truck to see over 10 mpg just ONCE. Even at a solid 70 on the interstate using cruise, it never tops 10. Gonna do plugs & wires asap but not expecting huge gains from that.

 

But that's the great thing about a vehicle with bad mpg, you see huge gains in upgrades that would not be an noticable in a car with high mpg.

 

I drive 55 miles one way to work and 65 miles home (different route home to avoid traffic) 5 days a week. I'll take the 1 MPG even though I get 22 MPG in the truck.... all freeway driving.