well i finally got my predator and had it on the 65 hp for about 1000 miles. gas milage sucked i got 13-15 mpg. it was fun but not practical. so i took the hit and put the 40 hp tune in. i got 1200 miles on this tune. at first i was breaking even i got 19 mpg with my atv in the back on the highway going 75-80. thats average. well on the way home i dont know what i got exacly but it was good. then all the running around i did. since sunday i did 556 miles. and i filled up to day and put in just under 26 gallons of fuel.
now
300 of this is highway with tolls and traffic.
then monday i had to go to boston well i completly forgot what i was doing and drove 40 miles past my exit. so thats anouther 80 miles extra. plus wot because i was so late and mad. that KILLED my milage. i uses about 1/4 tank that day.
then boston traffic so that was stop and go same thing for the way home. thats 43 miles each way. then the same thing to day. the rest of it is just running to stors and around town
so if i didnt get lost and burn all that other fuel i am guestamateing low to mid 20's for mpg.

my shifts points are low 1600-1900 and no more than 2100 when getting on the highway. this may varrie between truck but this is exacly what i got.

yamahagrizzly;

How many total miles on your truck? Do you feel the predator helped you mileage or were you getting these #'s before?

I`ve been running in the 65 mode and getting about 1-1/2 mpg better than stock. Think I`ll put it in the 40 mode and see what the difference is.

i got 18,3?? my milage before was 17-18 around town and 18-20 on the highway. power wise with the 40 hp isnt great. but its notice able. i think the drive ability of the 40 is great also. i bought the predator for a little more towing power and something to play with while out on the weekends.
i cant garrantee that others will be getting this kind of milage. theirs allot of factors that involve fuel consumption.
i just dont want to be held responceable if any one go and buys this tuner and they dont get the same milage.
over all i am very happy with my truck and programmer. i dont beat on it much because im in it for the long run and dont want to trade in every 2 years.

Just filled my tank for the first time (the dealer filled the first one)
and checked my mileage. 21.3 mpg! And it is supposed to get better?
Is this typical for others? I am considering adding some module or programmer for more power for towing but would like to improve fuel economy for non-towing times. Any ideas on which unit may be best for this?

Thanks!

Just filled my tank for the first time (the dealer filled the first one)
and checked my mileage. 21.3 mpg! And it is supposed to get better?
Is this typical for others? I am considering adding some module or programmer for more power for towing but would like to improve fuel economy for non-towing times. Any ideas on which unit may be best for this?

Thanks!

I don't mean to insult you but, are you sure about that calculation. I just got my truck last week and the best I've seen so far is 13.5 mpg.

My father in law had similar numbers but not quite as good. I cannot be sure how full the dealer filled my truck. The guage showed full. When I filled the truck, it was completely full and the numbers were at 21.3. I'll let you know what the next mpg comes in at. It sure seems that there is a pretty large variation of mpg here in this forum. I hope your does improve!
My truck is bone stock, so far.

2004.5 Chevy x-cab 4x4

I hope your does improve!
My truck is bone stock, so far.

2004.5 Chevy x-cab 4x4

So do I, Thanks

hoppyray, If you are getting 21mpg on winter blend fuel, you are doing alot better than most people are doing with tuners. I would be happy with what mpg. Is your truck 4x4? I was getting 19mpg after I changed to a 4:11 gear. Since the winter blend of fuel has come out, the best I can do is 17mpg.

Hoppyray,

No offense but that sounds too high to be true. I've done everything to try to get above 17MPG and have nt been able to do so.

Maybe your dealer filled the tank as full as it could go but when you filled it it clicked off when the foam rose and you called it full????

I know if I stop filling when the foam clicks the nozzle off the first time the gauge will show full but I can still put a couple more gallons in if I let the foam settle.

Just to add to this. I have had my truck for 6 days and 850 miles. The computer digital readout has computed a steady 16.5 MPG. I have not reset it as yet but will on the next fillup and compute it myself by crunching numbers and comparing it to the on board computer. I have the 4X4 extended cab 8' bed.

Most of the driving 90%, is freeway at 70-80MPH here in SOCAL. I don't believe we go with winter fuel here?

This is a great board, and I will input my experiences with this vehicle.
I also own a 1986 Ford F-250 with 120K on the odometer. The transmission was the weak link in that rig, along with many accesories electrics, etc. The truck is self destructing before my eyes. I have a Crown Vicky doing the same, and an Escort. All the trannies seem to go at 50 60K miles. So I will replace them with GM products!

The Allison is familiar ground for me, as I sold high line Motor coaches(Foretravel) for a few years, with legths up to 42', and I loved the Cummins/Allison combo. Unbeatable and indistructable in my experience. It sold me on this rig, and I do love it so far. Ford trucks seemed to always track wrong, but this Chevy seems real tight in the front end. I have yet to get her dirty, off road, but that is next!

I tow #20K GVW, 40' 3 axle 5th wheel, Kountry Aire, and a 2002 MacGregor 26X sailboat with a 50HP outboard on the transom.

Thanks again for a great board

I have 1500 miles on my 05 Duramax and am also running the 65hp Predator. A recent trip to Fresno I got 16 mpg. 15 on the return trip. No bad really. I assume it will improve as I get more miles on the truck.

When calculating mpg on our trucks, you need to do an average over about 5 or 6 fill ups to get something that makes sense. The way diesel foams when filling up can make a 1 to 2 gallon swing every time. I usually wind up putting almost 2 gallons more in my tank (26 gal SB model) after it first clicks off. Yes it takes me 5 minutes extra to do it, but I usually fill it until i see liqued (not foamy) diesel come up in the filler neck and "stay". I can easily take my mileage over 20 by filling it completely up using the method above, then on the next tank just filling it up till it clicks. By doing it over 5 or 6 fill ups, you get a better picture of what your real avg mileage is.

12k miles on the truck.

Best tank 16.3 MPG
Average tank 14.1 MPG
Worst tank 10.9 MPG

All hand calculated and adjusted for 285s.

I have not idea how you get 20+ mpg. This is my second duramax and my last truck never got close to 20mpg and I don't think this one ever will either. I drive 80 mile round trip on the highway cruise set on 70-75 every day.

My average fill up point for my CCSB (26 gal tank) is around 300 miles. I would **** my pants if I filled up after 500 miles :eek:

??? Searay90 If you fill-up that way, you are shorting your gallons "a 1 to 2 gallon swing " each fill-up. Thus, you are calculating MPG with fewer gallons than actually used. Resulting in artifically high MPG's. To get proper MPG you need to fill-up to the neck each time. Different pumps pump out faster than othere, resulting in more foaming which clicks-off the pump quicker.



When calculating mpg on our trucks, you need to do an average over about 5 or 6 fill ups to get something that makes sense. The way diesel foams when filling up can make a 1 to 2 gallon swing every time. I usually wind up putting almost 2 gallons more in my tank (26 gal SB model) after it first clicks off. Yes it takes me 5 minutes extra to do it, but I usually fill it until i see liqued (not foamy) diesel come up in the filler neck and "stay". I can easily take my mileage over 20 by filling it completely up using the method above, then on the next tank just filling it up till it clicks. By doing it over 5 or 6 fill ups, you get a better picture of what your real avg mileage is.

??? Searay90 If you fill-up that way, you are shorting your gallons "a 1 to 2 gallon swing " each fill-up. Thus, you are calculating MPG with fewer gallons than actually used. Resulting in artifically high MPG's. To get proper MPG you need to fill-up to the neck each time. Different pumps pump out faster than othere, resulting in more foaming which clicks-off the pump quicker.You might want to re-read my post. :) I do consistantly fill mine up to the "neck". and I average about 17mpg BUT, I told him that if I do a "short fill" and only fill it up till it first clicks off then I am 1 to 2 gallons short and the resultant calculated MPG will be upwards of 20 MPG. So saying your getting 21 mpg is not accurate as your calculating it only an a data sample of ONE. You need at least 5 data samples (fill ups) to get a decent average you can talk about. AND you need to fill it up till the liquid diesel stays in the filler neck so that all 5 data samples are the same (well as close as we can get it).

The way diesel foams when filling up can make a 1 to 2 gallon swing every time. I usually wind up putting almost 2 gallons more in my tank (26 gal SB model) after it first clicks off. Yes it takes me 5 minutes extra to do it, but I usually fill it until i see liqued (not foamy) diesel come up in the filler neck and "stay".I’ll second that, try filling up with one of the fat pipes at your local truck stop! I just returned from a trip to the Oregon coast over Christmas and was filling up at the big rig fuel stops, man those things can pump some fuel! When the pump would click off I’d wait several seconds and start up again, I was able to consistently get 4-5 more gallons of fuel in my tank due to the foaming of the high speed pumps. I don’t pump fuel up the neck till it’s at the opening but I do pump till I can see fuel in the neck

Running the Predator tuner I was getting 20MPG running pretty constant 75MPH going to Oregon from Reno. I hand calculated because my DIC was showing 24-27MPG!!! I knew there was no way I was getting that good. My normal MPG’s hand calculated before I installed the Predator tune were close to what most on this forum are reporting, 14-15 in town and 17-18 on the highway, I have noticed an improvement in my MPG’s with the Predator. Roughly 2MPG’s better with the 40HP tune, it’s not a lot but to get extra power and better MPG’s to boot, couldn’t ask for much more.

out of the last few weeks my worst mpg was 14.5 mpg during 2 snowstors and allot of travleing in 4wd. and allot of hot rodding. my average mpg with the 650 hp pred is 20 mph for both city and highway. i will start takeing loggs so i can prove to you that i can get 20 mpg.
right now i an at 250 miles at just over a half a tank. that includes traveling 50 miles in 4 wd yesterday during the snow storm.

if i was gona make up stories i woudl say i got 25 mpg at wot for 600 miles.

not sure if i said it before but i fill my tank till i can see the diesel in the neck.

.... with the 650 hp pred ...
WOW! :ro)650 hp preditor. Mike L. must have done some real magic on you Ally.

Jim

Searay, Agreed, your post was just a little confusing when you mentioned "using the method above" in that there were 3 methods "above."

Ditto on the foam, to get a reliable reading you do need to fill to the same level each tank to have an acurate reading on fuel ecomony. If I am patient I can get 2+ more gallons in the tank.

on my truck the fuel tank is the same as it was the day i drove it off the lot. its a one ton but not a dually, regular cab. Full to empty I can get about 540 miles to a tank. thats full to the brim until im down to fumes. you do the math.

Yamagrizzly:

Are you calculating the MPG or using the on board computer? Feedback from my customers has been that both GPS and computer are off approx 3-5%. I've had customers that claim 19-20ish on computer but realize an actual 17-18ish when they do the math. The most accurate is doing the math. I've got and LB7 and I've never hit 20mpg yet with over 50-60K on the truck. Just curious.

Thanks

Yamagrizzly:
Feedback from my customers has been that both GPS and computer are off approx 3-5%.
Putting a tunner in also screws up the GPS? Amazing. How does that happen?

Jim

on my truck the fuel tank is the same as it was the day i drove it off the lot. its a one ton but not a dually, regular cab. Full to empty I can get about 540 miles to a tank. thats full to the brim until im down to fumes. you do the math.

How much fuel does the long bed hold. I know you guy's can fit more than us short bed drivers.

When calculating mpg on our trucks, you need to do an average over about 5 or 6 fill ups to get something that makes sense. The way diesel foams when filling up can make a 1 to 2 gallon swing every time... ...then on the next tank just filling it up till it clicks. By doing it over 5 or 6 fill ups, you get a better picture of what your real avg mileage is.Here's an idea... Those of you who have the DIC fuel consumption readout can use it to check and make sure you're adding roughly the same amount of fuel that was consumed by the engine. Once you've topped off one tank, the next time the gallons used/pumped should end up to be very close. Mine usually ends up to be within a tenth of a gallon using this method. That way I know the DIC (and my own math) is not playing tricks on me!

I think the SB has a 26gal tank, the LB has a 34gal tank... http://www.gmc.com/specs/specs_content_files/specs_print_all.jsp?brand=sierra&vehicle=2500hd

-AJ

Has anyone noticed that after the reflash, the DIC readings were approx. 8% more optimistic. Thanx Geo.

Here's an idea... Those of you who have the DIC fuel consumption readout can use it to check and make sure you're adding roughly the same amount of fuel that was consumed by the engine.
Oddly enough, I hadn't thought of that . . .

after reflash my fuel used and milage indicator are off 30 percent. iam curious if milage on odometer is accurate? pulling a 2.5 ton boat fuel milage about 12 at 80. getting 15 local. nelson 05 chev

My LLY gets about 18 in the city and 19 on the HWY. Done by hand and the DIC shows the same average, I do fill until I have fuel in the neck. My LB7 gets about 13 city and 17 HWY and it has over 255,000 on it. The LLY has 17,000.


On my LLY I have thes urge issue at 1000 RPM, but with all the different info i am hearing about poor mileage, inacurate DIC after the reflash and other issues. Should I really have the reflash done?:eek:

yeah 34 gallons in my truck sounds just about right on

ya long beds got 34 gallons.
no i do not have the dic and i wouldnt trust it if i did.
as long as you dont beat on your truck and dont go over 2000 rpm's the fuel milage should be good. if not them i dont know what the problem is.

i fill my truck every friday. some times it takes 5 gallons and others it takes 30.

I have a 2005 GMC duramax & the best i can get is an average of 14-14.5 mpg between highway & city driving, and i only drive 70 mph on highway. Iam pretty disapointed in the mileage so far and hope it gets better with more miles. I only have 8000 miles so far on truck. If anyone is getting 20 mpg they aren't driving the speed limits on highway in my opinion.

On my 04.5 LLY, I am getting 17.5 mpg highway and 16mpg city. Everything is bone stock and I have 1 ton of materials in the bed (tools, cables, etc.). When on hwy, I go anywhere from 75 - 95 mph, depending on traffic and law enforcement presence. I have 58000 miles on mine now in the past 8 months. I use Stanadyne as an additive to increase the cetane levels and keep everything clean. I have yet to have a problem. I did have water get to my injectors the one time I didn't place and additive, dumb on my part. Poured some stanadyne in the tank and it cleared. Then changed the fuel filter for good measures. Everything is still original on this truck minus the filters and tires, due to normal maintenance.

I have found that the most accurate way to check my average mileage is to fill up, write down the mileage, then run a few tanks and take the numbers again later with the tank full. This gives you a better average as the mileage check is spread out over a few tanks and there is less concern from not filling exactly the same as the 1st fill or from filling while being parked on uneven pavement. The more tanks you run the more accurate the calc. I have been consistently around 18 MPG.

04.5 lly, 245 tires, speed was off 3.5 mph. I thought I was getting 18 mpg. Replaced tires with 265's, now my speed is off less than .5 mph. I asume this is correct because I took a trip(2 full tanks of fuel) with a Lowarance & a Garman Gps on the dash. Both read same mph & distance traveled. Compared fuel used (DIC) vers fuel replaced, same. Stock other than tires and no towing, no racing. New mpg is 16 to 16.5. I got 16 with my '98 gas 350 Chevy full size extended cab, wish I still had it. Sounds like a lot of fuzzy math on this site. Wouldn't own anything but a Chevy.

I am sorry most disagree with my numbers.:( As I said the gauge read full from the dealer and I filled it until I could see the fuel. I will update this after my next tank fill up.

I put the edge on a few tank fulls ago. This last tank I tried to keep the lead out of my foot but I did run on level 3 a couple of times hitting the speed limiter. I'd say that probably 90% of my tank was driving "normal" which means for me 65 freeway and easy on the streets. I got 18mpg this tank and the DIC showed 18.6mpg which is a lot closer than it used to be. Before the Edge my DIC showed 20.4mpg and I'd actually get about 18mpg hand calc'd. I'm going to try like H**l to keep my foot out of it this time and keep my finger off of the Attitude while driving. I want to see if I can get an improved mileage with the Edge.

I got 16 with my '98 gas 350 Chevy full size extended cab, wish I still had it.
I had a '97 Ext SB Z-71 with a 350 that would consistently get 19 mpg @ 70-75 mph. Gotta love that):h . It had adequate pulling power as well. DMax still rules:ro) !!