Edge Evolution CTS on Duramax +18.8% (or +3mpg)

[joggerfogger]

I seriously doubted that a $625 programmer (I paid $375 used) could actually make a difference.

The problem is that the programmer screws with the fueling tables in the ECM and in the past massively screwed with the DIC (driver's information center on GMs). So the Dashboard computer would say 23mpg, and when hand calculated, the number was more like 17mpg. Throw into the mix that almost every diesel truck driver puts on bigger tires (including me) you've got a semi-complex math problem for the average diesel dunderhead.

So I hook up the programmer and immediately I see +3 mpg averages on the DIC. I immediately didn't trust it as it had a +/- 0-5% error every tank anyway vs. hand calculating.

So I finally fill up again and the DIC says an optimistic 15.8 and hand calc was 16.1. For the same driving before the programmer was around 13mpg. Now one tank is not a good study, but it's amazing considering the only thing I did was hook up the programmer.

I use this truck for many different tasks, but the only time it sees the highway is with a 6,000lb RV trailer behind it. The rest of the time it's 6mi to daycare, then another 6mi. to work, haul a load of firewood, move a friend, etc. etc. repeat.

Yes, I get really bad economy, but I drive in the worst possible conditions for short trips, in bad traffic, over two 900ft. hill two times every day. I'd love to run a whole tank on the highway, but if I was going to do that without the RV, I'd just take my 32mpg Golf.

An improvement of 3mpg is substantial to me.

[Backtobasics]

There is a lot of untapped potential in the average diesel truck, as the OEMs do not know what the person is going to do with it. There is such a large range -- Fully loaded all the time (lawn and landscape), around town combo use, or unloaded high performance enthusiast. As such, they can't the more aggressive tune, as the guy who works it hard loaded, would kill it. The diesel programmer market is huge, as they can give huge power and torque gains for moderate cost, yet almost all have multiple levels, and they highly discourage towing and loaded use in the more aggressive settings for the engine damage reason.
This is also the reason that these vehicle respond so favorably to the other 2 common modifications, air intake, and exhaust. The engine is not restricted by throttle blade such as gas motor, so unrestricted air intake has benefits, and low restriction exhaust compliments the turbo, which likes reduced back pressure.
I wish I could trade my moderately lowered 2wd gas truck for the same in a diesel, I bet I could go from the 15 I get now to 25+.

[joggerfogger]

Completely agree.

So this truck replaced 3 vehicles for me:
1. BMW 745Li (16-26mpg) $30k
2. Tacoma 4x4 (15-20mpg) $5k
3. Airstream Motorhome (6-7mpg) $14k
It's almost as nice as the BMW and will carry 5 full adults. It has 4WD like my Toyota, and I can pull a RV trailer when I need to. I race motorcycles, fly hang gliders, and camp (RV) with the family.

I read extensively about efficiency with this truck on all sorts of forums before and since I bought this truck. Insane amounts of reading. I would guess +200hrs.

I have the LBZ motor found in the 06-07 "classic" models right before the body redesign and adding of the DPF (diesel particulate filter) systems. All the mods for better FE (fuel efficiency) are to use the LBZ intake and delete the DPF. My conclusion after reading reports from respected tuners and enthusiasts alike, is that the stock intake is about as good as it gets until you go over 500hp. Same thing with the 3.5" exhaust; going to a 4" exhaust won't help unless you're demanding flow increases to support +500hp. (360hp is stock).

I did buy a cat delete pipe, but I'm waiting to establish some baseline numbers with the tuner alone before I swap out the kitty. From what I've read, there are negligible FE gains to be had with the delete, but the EGT (exhaust gas temp) should drop with the same conditions. But for $63 I thought it was worth a try.

-Kevin

[joggerfogger]

So this tuner has 4 settings:
1. Economy +30hp +60tq
2. Towing +60hp +135tq
3. Performance +85hp +185tq
4. Extreme +100hp +220tq.

Stock is 360hp and 650tq. There's "race" versions of this tuner that will do +225hp and +335tq with just a tuner. It's really amazing.

The transmission builders agree that +85-100hp is the most you can go without doing damage to the transmission.

What's interesting is that I'm getting slightly better numbers on level 3 than I am on level 1. Ever so slightly, like 0.5mpg, and completely unscientific, just watching the mpg on the dash readout. Many users find the same thing, but I find it weird that the designers of the product wouldn't make the Economy setting the most economical?
1. maybe level 3 is more efficient, but it's harder to stay out of the high power.
2. maybe it's a function of using more power smarter via pulse/glide theory.

-Kevin

[NHRABill]

The diesel truck tuners are fun and glad to hear that you are having a good initial experience. Start a log and keep track of your mpg so you can test out different driving habits it will surely help in teaching you how to drive that truck better.

I sold a 2002 Chevy S-10 4.3 5 speed and 1978 Chevy fullsize straght 6 3spd manual and a 2002 Pontiac Aztek 3.4l v6 and a 4x8 trailer when i bought my cheap used 1995 Tahoe. Cost wise I saved a ton even though my mileage is less I experience same driving conditions as you daycare runs and towing other than that I ride my motorcycle or take either the wife's Cadillac SRX AWD 4.6 V8 24-28mpg hwy or her Olds Alero 3.4 v6 26mpg average.

You get great mileage from your Golf that must be nice for those longer trips.

Looking forward to seeing your continued improvements.

[joggerfogger]

I have two 1985 Honda Sprees that get 98mpg and a 1982 GS1100E that gets about 33mpg.

For some reason I'm not really excited about ecomodding the Golf. I feel like I'll get more % results from working on the truck.

I use a iphone app called Gas Caddy to track my fuel usage (on all the vehicles). But it's kind of hard to interpret since I use the truck for such a variety of activities. Since I have a hour meter, I was recording the hrs vs. miles to get a average MPH for the tank, but I stopped doing it because every tank was 25-30 mph average.
The hight spot when I bought the truck was the drive home. A partial tank of 160 miles highway. The rest is either commuting, pulling a trailer, or a boat. The worst was when I was putting a 8,000lb boat in the water every day and towing it over mountain ranges.
Ideally, I'd like to build a "fastback" or "aerocap" if I can figure out how to make it cheap and look decent. And then the rest of the mods will be "stealthy". Like underbody coroplast and behind-the-grill blocking.
I'll be sure to document everything I do and post it here.
-Kevin