Tree DR

Has anyone tried driveing on the half power setting to see what kind of mpg you'd get?

djbikeman

I don't know if anyone has, but I am of the opinion that it won't do much.

Here is my reasoning. If it takes 100hp (I don't know/just throwing that number out there) to keep a CTD at 60mph, then it doesn't matter what the max hp of the motor is, it will still take the same amount of fuel. That is why a 700hp CTD can get the same mileage as a stocker.

The difference that most programmers make in improving mileage is that they change duration and/or timing to make 100hp more efficiently with less fuel. With this increased efficiency, comes HP increases under full throttle. Most people will report the same or better mileage increase at the higher Smarty settings with timing, 7 and 9, that they got at level 1 and 3, even though you wouldn't expect it.

Tree DR

I agree with your thinking. Just heard some things that made me wonder.

t-boe

How would you explain why the older 24 valve and 12 valve trucks got better mileage than the common rails?

MikeyB

Several reasons, many of the earlier trucks have 3.55 gears, vs. the 3.73 for the 3rd gen. Also the CR's have extra injection events that requires more fuel. For emission reasons the CR's is running less advance timing compared to the 12v or early 24v engines which doesn't make the engine as efficient in the use of fuel.
Last but not least the CR's make more power.

MikeyB

Tree DR

Makes lots of cent for some one, not me. As said earlier more HP doesn't mean less MPG if you don't use the HP. So emissions are a issue. First lets make them less efficient (timeing=more fuel) so they produce more emissions and then add a cat to catch those bad emissions which makes it less efficient =(more fuel) and put lower gears so its rpms are higher =(more fuel)?????????

MikeyB

Retarded timing reduces the NOx emissions. Increasing the EGTs will help burn off the rest and helps keep the cat hot for the catalyst.
Nobody said the EPA is smart.

MikeyB

abc4yew

I'm running mild torque management SW 9 now and I'm getting the best mileage yet and even with my aftermarket injectors ....no timing rattle. I got ok mileage on the Aftermarket Injectors program but my injectors like the timing it seems. I'll post the mileage figures after a couple of tanks but I'm driving really conservatively .... max 65 mph (our fastest speed zones here are 55mph) and maybe 50mph on the uphills. If we were able to eliminate the other injection events and run auto adjust 23 degrees timing ..... a six speed CR would kill a 12 valve in mileage. Gotta remember that a 12V truck is more than 1000 pounds lighter than a CR truck. ks

Tree DR

They have been talking about tuneable cummins power. If it is possible that sounds like the way to do it. Get rid of the third injection event and increase timeing and maybe good mpg?

Bob Wagner

we already removed the 3rd injection event and lost 100 hp and got higher egt's

cquestad

F1 injects like the timing programs!

RAMRODD

Why not try just one event like the 12 valve At least then we could hear the engine
I have run several New John Deeres and for example a 8430 uses pilot injection until the engine gets to about 100 the pilot injection stops then it sounds like a regualar diesel. These tractors have fuel consumption moniters and you save about .2 gal an hour after the pilot injection goes out, and that is just at Idle!!
Another tractor I have run was a JD 7920 with the same results. To me it seems pilot injection just burns extra fuel. And in my opinion is to make happy people that want a quiet engine, and of course emissions.

Tree DR

RAMRODD You maybe on to something. Maybe it's not the 3rd it's the first one that really needs to go.