All you guys with brand new 2005 trucks....anyone see any differnce in performance / fuel mileage with the 2005's compared to the 2004.5's?? Wondering if the added torque output makes any difference?? Tell us about your truck!

Have too few miles to tell (under 100 - in various shops gettin equipped). I break mine in pretty hard - cleared the dealers lot and ran it immediately to 3500 rpm. First 500 miles I drive the hell out of a new truck - then just drive fast and try to get some mileage. Couple things to note - power seems about the same as my 2002 LB7, except my 2002 was about 2,000 lbs heavier when I equipped it. This truck will be that way in a couple of weeks so we shall see. Have front bumper (another damn rubber band) off to put on my "Hit me and die" bumper, and it looked to me that the radiator was a bit wider. Grill opening seems bigger for better air flow. Has a flimsy air deflector to shove air up in it. I have never seen a 04 LLY manual, but in the 05 manual, the General says engine temps to 250 are normal under tow, and don't worry until 260. While my 6.5's and 6.2 Banks Turbos saw up to 260 (actually to 275 once), my 02 DA NEVER went over 210, even at 33,000 lbs on the Grapevine. I ran this one up a couple of hills with the pedal on the floor and saw 210 so far, without a trailer. Haven't notice much else in 100 miles or so. Mine is a 3500 CC 4X4 LB SRW. In a couple of weeks, I'll run it hard on a short trip of 1500 miles and see what happens. By the way, I LOVE my new CHEV service manager. He came out for delivery (first 05 diesel they have delivered - more on the lot now), and asked me what mods I was going to make. I ho hummed, and he again told me he would warranty anything no matter what I did so long as I didn't get totally stupid. He has several other trucks running all kinds of chips, 36" tires, and other engine mods, and they all say he has stood behind them every time. We'll see. The last SOB GMC service manager would not wash the underside of my truck after 2 injectors cracked, dumped fuel in the crankcase for 3500 miles, and made my red truck look like a dirty brown fuel truck. So far, he has lost 5 new car sales for that dealership in 3 months. My goal is 20 new car sales lost for the year. Really Pi--ed me off!Edited by: gardnerteam

I wonder if anybody with an '05 has disconnected the EGR yet??

Mine runs reallly good an its my 1st diesel its a 05 cc 4x4 it averaged about 14 mpg on the interstate withthe org tires an wheels now im @ 500 mi. with hummer tires an wheels. So imsure it will decreaser a lil bit bu t as it gets broken in I hope mMPG will increase to @ least 18 mpg on the interstate @ say around 70 mph I HOPE.. Going to chanege the oil but not sure what to go with Rotella??? Devco I think its called???? What do you guys use?? So far I love the truck haven't heard hte famous tick yet so thats good!!!!!

skoryaro2-


I have an '05 and I disconnected the EGR at 500 miles. I have 3000 miles on it now and no codes with my actron scanner. It has slow turbo spool up compared to my '03 but I fixed that with the open filter. Gas mileage is still about 1.5mpg worse than my '03. I am going to buy the block off plate some of the guys on here are making.

I heard it that the 2005.5's are geting upgraded software and 605ft/lbs of Torque.

So far I love the truck haven't heard hte famous tick yet so thats good!!!!!


Unfortunately, you'll hear it after that first oil change.

2k4hd,

When GM released details on 2005's they said that they boosted torque slightly but HP stayed the same. I'm curious what they did to make the increase. I'm sure it was just a programming change but was hoping it would increase fuel mileage also.

No mention of 2005.5's

skoryaro2-


I have an '05 and I disconnected the EGR at 500 miles. I have 3000 miles on it now and no codes with my actron scanner. It has slow turbo spool up compared to my '03 but I fixed that with the open filter. Gas mileage is still about 1.5mpg worse than my '03. I am going to buy the block off plate some of the guys on here are making. Talked to Actron 2 days ago. Their code scanner does not read EGR codes. I took mine to the dealer and had 4 EGR codes that my Actron did not see.

RickDLance,

I'm assuming you have the EGR unplugged. Why the trip to the dealer and what did they say about the codes???

2k4hd,

When GM released details on 2005's they said that they boosted torque slightly but HP stayed the same. I'm curious what they did to make the increase. I'm sure it was just a programming change but was hoping it would increase fuel mileage also.

No mention of 2005.5's

All they did is tweek the perameters in the ECM, I doubt the fuel economy will change if at all. I heard that the 605's wont be avaible till the first of the year.

But IMO I think its more of a marketing thing than any thing else, its more for bragging rights against the Cummins 600

If it was bragging rights, it should be Dmax 750.


Quit nickle and dimeing, trump them good.

It's not like GM to release HP/TQ plans for future products. Now customers may be willing to wait a few months for a more powerful product, which is bad for business. But also, competitor diesels can bump up their #'s, and that too could be bad for business. Doesn't make sense.http://www.dieselplace.com/forum/smileys/Confused.gif

My truck had 10 miles on it when I picked it up on 8/5/04 as of Saturday 8/28 it had 1,785. During the break in period I followed GM's recommendations.

One thing I have noticed is my DIC is offhttp://www.dieselplace.com/forum/smileys/Ermm.gif (gotta love that acronym). As an example, if my DIC tells me that the average MPG is 17.00 and I fill the tank up, by topping it off, my average MPG is going to be 16.00. However, if I put in the exact amount fuel that my DIC tells me I have used the average MPG is correct. I took my DIC's advice for 3 tanks of fuel. By the time I filled the tank the third time my fuel gage did not read full. http://www.dieselplace.com/forum/smileys/Confused.gif

Living in northern Michigan most of the roads that I travel are 55 mph, which I believe has helped my average MPG. My low MPG is 12.63 and my high was 19.05. My average MPG over 7 tanks of fuel has been 16.61.

This being my first diesel I have nothing to compare the horsepower or torque to… I do know that I love this truck and look forward to making a few mods to it this fall and next summer.

The next big test will be when we take our fifth wheel (approx. 8,000 lbs) on its maiden voyage this weekend.

I'm glad to see u got a purdy GMC.


Most of us have found the DIC to be off some, but it is still handy to have it.

skoryaro2-


I have an '05 and I disconnected the EGR at 500 miles. I have 3000 miles on it now and no codes with my actron scanner. It has slow turbo spool up compared to my '03 but I fixed that with the open filter. Gas mileage is still about 1.5mpg worse than my '03. I am going to buy the block off plate some of the guys on here are making.


Talked to Actron 2 days ago. Their code scanner does not read EGR codes. I took mine to the dealer and had 4 EGR codes that my Actron did not see.


Which scanner are you using? Did you happen to ask if any of the Actrons read those codes, or just about the one you have?


Some of those codes will be GM specific, but others are part of the emissions equipment and should be generic. I would think a failed EGR would be part of the generic OBD II stuff for emissions...http://www.dieselplace.com/forum/smileys/Ermm.gifEdited by: Zeeb

Smoky,

Let us know how the "plate" mod does once you get it installed. Curious if any diff between 2004.5's???

My Actron scanner (9135) will read the same codes that the guys are having (I forget the specific number) on my VW GTI but not on my truck. I am going to check the codes with another scanner to see what I get. I am sure the EGR is a "generic" DTC because of emissions testing in some states. If the car came with emissions controls the govt. mandates they be working.

My actron scanner reads all my EGR codes fine.

My actron scanner reads all my EGR codes fine.


which scanner do you have?