CE Zero

OK Guys;
A question for you...
I've recently did 3 seperate trips to Shelton, Washinton from Vancouver,Wa. The round trip is 272 Miles all freeway except for a mile or 2 on each end. The Truck was running an empty bed, filled with fuel (At the same Pump (Start/Finish) and the Mileage reset at the start of each trip and Cruise was set at 70MPH. (Smarty JR ME)
Trip #1 was set @ Level 2 (Towing - +70hp)- MPG 22.5
Trip #2 was set @ Level 1 (Economy - +40hp) - MPG 21.5
Trip #3 was set @ Level 3 (Perfornamce +100)- MPG 23.1
POD was set @ 65 for all 3 - What gives? One would generally expect the milage to drop as the HP goes up. Don't get me wrong as I'm pleased with these numbers, I'm just a little confused.
Milage was hand Calculated.
Dana

sheriffav8r

I think mileage drops when you USE the performance. The chips/programmers use fuel injection timing and amounts to increase horsepower and torque over a spectrum. That is different from older gassers that have aggressive cams, etc., to build horsepower. I believe that if you run max performance chips and drive very conservatively you will see the best mileage. Some people don't like that very much when the cruise is on because you get a ramjet effect felt as pulsing that is somewhat annoying....JM2C

Blake Clark

Nope

Remember that the POD function is NOT linear.

For the given increase in HP on certain tune the POD responds in a much different way and the derate it performs is drastically different.

Its apples to oranges to prunes.

Just find what works for you and stick with it. Personally Id be staying with Door #3!

madhat

HP to weight ratio. That's what I was told.

Scotty

My best mpg is always on SW 3 with the options either set at default or all but VGT set at 1.
My truck weighs 9200 pounds and I can net over 21 mpg if I keep the speedo between 60-65 mph. I can net low 19 mpg 65-70 mph. After that it drops to 17 til about 80 mph. Then... She glides along real nice but mpg will be in the mid to low teens. I had to get to a location quickly one night as a friend was stranded and storms on the way. I was cruising at 90 mph for an hour and 20 min, the mpg was around 12. glug glug glug.
I had the blessing of an escort from a LEO friend of mine on that run.

Lil Dog

That is correct. The amount of HP required to push your truck at 70 mph doesn't change other than wind and weather factors. So it doesn't matter if you have 1000hp , if it only takes 130hp to go down the road thats all you use. Mileage will not change..... much...

Now the tuning of the program can play a factor in combustion efficiency with respect to timing, fuel pressure, boost etc but all in all, the changes aren't that drastic. 1-2 mpg over a stock program would be the most. Where you make most gains with those programs is in the acceleration mode. Having more fuel down load can cause reduced mileage. However, if you have better programming for smoke reduction (ala Smarty) you can have improved mileage in town.

The biggest difference would be towing. If you have more power, you will use it and that takes more fuel. Near stock program and I can get near 12-13 mpg pulling my TT. I towed a shorter trip on level 5 with some hills and it dropped to 11. I make the hills better, but pay for it at the pump.

sheriffav8r

Yeah, what he said....

CE Zero

Thanks Guys, all good answers. Kind of makes sense when you put it all together. So let me get this straight:
The Smarty maximizes the tune to the HP setting, including timing and I assume Turbo speed (Pressure). With all this combined it may actually take less fuel to produce an equal amount of HP at the different tune levels. Is this about correct?
And Blake, I'm not understanding this non-linear thing on the POD. Is it of more help on acceleration? My in town milage doesn't seem to change all that much from setting to setting (16-17 MPG depending on the Lights) and that doesn't make a lot of sense either as I seem to be depressing the Accelerator about the same distance no matter the setting. I don't jack rabbit off the lights just steady acceleration.
So far I don't see a down side of the 100HP Tune except when Towing but then again I don't I don't drive it like I stole it.
Dana

Blake Clark

The POD being non linear:

This aint easy to explain sometimes.

Ok lets say if it was linear. On the 70hp setting the POD setting of 50 would equal 35hp. This is a linear function. Picture a graph with a steady increasing straight line. This would be a linear function.

Now picture a graph with a curved line. As the POD number would increase the HP would increase along the curve. So on 70hp a POD of 20 may be 10hp, and 70 may be 40hp... and so on. The POD number is not a direct percentage of any given HP, its just a point between 0 and 99 on a non-linear graph.

So to sum up that mess a given POD setting, say 65, for each tune, yields drastically different results. Now bear in mind, there are multiple variable being tuned here, fuel pressure, rail pressure etc... so its actually modifying several variable on a non linear scale. That is why different trucks perform different with the POD, because everyone has different supporting mods in place that are factors.

All in all, to find what POD setting works for you, you just have to play around with it.

Hope that makes some kind of sense.

CE Zero

Yep Blake, clear as Mud.
Actually I kind of think I get what you're talking about. I just started to play around with the POD, still haven't even started into the timing and torque settings.
Dana

mega-engr

Yes, it is confusing. Here are the instructions straight from the horses mouth:

http://www.madselectronics.com/downl...structions.pdf