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Issues with the Edge

867 Views 4 Replies 4 Participants Last post by  smally
All of these mileage figures are hand calculated enless stated.
I'm giving a lot of useless info here, but what the hell I can't sleep.

I purchased this truck in August of 2008 when the price of diesel had spiked and I was lucky to pick it up for $17,500, a real steal. On the way home I recorded 19.5 MPG @ a steady 65 MPH. I had wanted a dieself for along time but refused to pay the high price, so as soon as I got home I purchased an afe stage 2 and Silverline 5" turbo back exhaust. The day after I installed them we excuated for a hurricane and I got 22.3 MPG @ a steady 65 on the trip. I was impressed and had plans to purchase a high end $1000 tuner a couple months later, but then the oil moratorium hit and my income went from $1100 a week to $300 so I never got that tuner (as well as losing a lot of things I was used to like deer hunting and fishing every weekend).

During the next couple years I started to notice the seats in this truck are horrible, I think the engineers who put this in a high dollar truck should be pistol whipped. Then my AC stopped working when I'd come to a stop, I checked the freon and it was fine, the compressor was turning so I was baffled. I brought it to a mechanic, he said since it was this model Dodge Cummisn he was sure it was the fan clutch wire being ripped out. He slid under the truck and sure enought came up with a lose wire. Cost about $600 to fix he said because you couldn't rewire it it had to be replaced.

Because I couldn't afford it at this time I rode around with it like this for a year, turning my AC off at every red light and sweating my azz off in the humid summers we have here. The good thing about a broken fan clutch is my fuel mileage went up to 25.0 MPG @ a steady 65. I decided to sell it and go back to gas. I had it fixed and procrastinated on selling it and the fan clutch broke again. This is about the time I got a new job; with the deep water oil drilling coming back online I was able to change jobs to a 7&7 job (I work 7 days then get 7 days off) The bad thing is it's 120 miles round trip away, at first I slept down there but that proved to suck, so I decided to drive back and forth. Figuring I'd never get a gas 1/2 ton to get 25 MPG I decided to keep the Cummins, fix the fan clutch and get another seat.

To keep my mileage gains I ordered a Flex-O-Lite electric fan set up and an Edge Tuner ($300 range) from one of the dealers on here. I installed then both at the same time. I was thrilled by the extra power, but I was even more thrilled to see my computer mileage go from 24 MPG (actually 22.3 measured by hand) to 28.5 on my commute (nearly all highway miles, only 2 red lights and on point slowing down to turn).

However, when I had to fill up something was fishy, my miles on a tank had gone down. So the next tank I kept track of, the read out went up (28.4) but figured out I was making 20.1 MPG. So I'm not happy anymore, but to make sure I tested it for a trip I had planned the next month just to make sure it wasn't me using that extra power. Driving to Disney World and back (750 miles each way) I averaged 20.9 MPG @ a steady 65 (my computer read out was 29 MPG), less than what I had before the tuner and Flex-O-Lite.

The biggest slap in the face is my computer mileage going up, WTF? I understand the Flex-O-Lite might be responsible for some of this loss because of the extra alternator use, but the computer mileage going up can only be the Edge tuner. I was getting 25 MPG without a fan clutch, with Edge's promise of added MPG I was expecting better than 25 MPG and I'm not getting 21.

Am I being cynical here? Is it out of the realm of possibility that Edge pumps up the computer read out to make peolple happy all the while they're losing actualy MPG?

Simply put
19.5 MPG @ 65 stock (75,000 miles)
22.3 MPG @ 65 w/Afe Stage 2 and 5" turbo back Silverline Exhaust
25.0 MPG @ 65 w/Afe Stage 2, 5" turbo back Silverline and broken fan clutch
22.2 MPG @ 65 w/Afe Stage 2, 5" turbo back Silverline Exhaust and fan clutch fixed.
22.8 MPG (commute almost all constand 58 or 65 MPH 3 stops or slow downs) w/Afe Stage 2, 5" turbo back Silverline, and fan clutch fixed
20.1 MPG (commute almost all constand 58 or 65 MPH 3 stops or slow downs) w/Afe Stage 2, 5" turbo back Silverline, Edge Tuner and Flex-O-Lite electric fan.
20.9 MPG @ 65 w/Afe Stage 2, 5" turbo back Silverline, Edge Tuner and Flex-O-Lite electric fan.
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Edge isn't "pumping up the computer read out to make people happy". The truck's computer thinks it is using less fuel than it really is.

I don't know what model programmer you are referring to but lets take my Edge Juice for example.
My Juice plugs in between the truck computer and the injector harnesses (front 3 on one plug, and rear 3 on second plug). It also plugs in-line of the MAP sensor (reads and fools boost reading to truck computer), along with another that I'm drawing a blank on at the moment.
The Juice takes IN what the truck computer is telling the injectors to do, modifies injector duration, and then the Juice commands the injectors. So what the computer is telling the injectors to do and what they are actually doing is two different things. This is why the fuel economy meter of the truck reads significantly higher than your actual fuel economy. The higher the power level, the higher the difference in the two calculations. This is one of the ways you get more power, the truck tells the injectors XX-duration, the Juice then 'amplifies' XX, then injectors react at the amplified value.

I ran my Edge on stock (0), 1, 2, 3, 4 on the same road at the same speed (SLC to near Denver when I was working there last year) every other week for months. My hand-calc mileage never suffered from the changes in power levels (or went up), but my overhead reading would get wild high. On setting 1 (what I normally run), it usually reads 3.5-4mpg higher than actual. 0 reads 2-3 high, I've never removed the Juice to see if they get any closer. This was done on an empty truck, cruise set at 70mph, and only 1 stop in 465mi for fuel (stop mid way because it was the cheapest along my route), my hand calc was 19.7-21mpg, overhead was approx 20.8-24.6 on setting 1.

When towing (on level 1). My overhead still reads high, but the numbers are closer. Remember that the difference in the readings can be considered a percentage of error, and at 0mpg you are still getting 0mpg and the overhead knows that you haven't moved. So when you are getting lower fuel economy (due to towing heavy), the overhead will read closer to your actual economy... Mine were ~2mpg different at 12.5mpg while towing.

Hope this helps you understand what is going on with your rig a little bit.

Also, I'm running my stock sized tires at 80psi, and when I hit the highway I rarely stop till I need fuel. On an empty truck at 65-70mph, I can bet that I'm going to get at least 20mpg as long as I didn't have a headwind.

Okay, this explains what I was pissed about, but why did my mileage go down when I installed the Flex-O-Lite and Edge? It wasn't just a little, it went down a lot.
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