Hello everyone. I just purchased a 2005 2500 4wd 4 door duramax. I love the truck, and currently get around 15 mpg. Im leaving the tires and and height stock, but would like to do a couple mods to up the mpgs.

Ive read about the cai from keepmyduramaxcool.com and plan on it.

2nd, i want to do the egr block off, and this being an 05, ill need the fingerstick, correct? Where do i find the fingerstick and the template for the block off plate, ill make that myself.

Next, where is the best pcv re route kit?

What is the best programmer for mileage?

Anything else anyone here can think of, besides keep your foot out of it, lol, please share. Thanks, ive done alot of reading on this site, and everyone here seems very knowledgeable.

Sean

I would think if 15 is highways miles per gallon you have a problem to fix first but if in town it is doing good.
chevman

you should first start with an air intake ,then move to an exhaust system, then decide on a programmer or tuner that suits your needs.all these mods work together for better performance and increased milage depending on your tune and the weight of your foot.

my driving is mixed, but mostly city. in my 20 mile commute i spend about 15 miles in the city and 5 on the highway, and during the day i make many short runs around town to pick up parts, and they are 2-3 miles each.

btw, i meant to say, i do keep my foot out of it, i try to keep the rpms below 2000, i prefer 1800 if at all possible. it accelerates just fine there.

15 mpg at best before EGR blocker and fingerstick (Kennedy Diesel sells that), K&N air filter and Edge Juice with attiude. Now I am getting 18-21 mpg empty. Last week I pulled 34 ft fifth wheel camper with a jetski in tow behind cruising at 65 mph and 1950 rpm for a 220 miles round trip to a lake and got between 12.5 to 14.6 on DIC. Hand calcuated at fuel pump confirmed that at 13.6 at end of trip. all of that on cruise control!

fill up, use a GPS to log miles, fill up to measure MPG accurately. With my programmer, 35's and mixed normal driving during commute (85miles round trip) = 17.85. I'm sure it's close to 20 on hwy only. I'll test hwy next time I have a long trip.

Draft large truck,because they have slowed down also. With the mods I made plus exhaust i gained 2-3 mpg. Plan to change the lly mouthpiece for a lbz mouthpiece. Currently get 13-14 towing my fiver ,19-21 empty highway. ScangaugeII is a excellent watchdog for watching current mpg,driving like a egg is under my foot. Get 10 when I'm having fun tho..

K&N air filter

Uuh... NO. You want to get that TxC CAI from CoolMyDuramax.com and use your stock air intake box with the AC Delco filter. It's been proven to be the hands down best filter for your truck. Read the definitive research here:

http://www.dieselplace.com/forum/showthread.php?t=117009

K&N has an impressive story, and they look good to boot. However, you can easily end up with oil all over your MAF, and then you're gonna wish you'd never even heard of K&N. YMMV...

TxC's CAI added 1-2 MPG to my rig...

fill up, use a GPS to log miles, fill up to measure MPG accurately. With my programmer, 35's and mixed normal driving during commute (85miles round trip) = 17.85. I'm sure it's close to 20 on hwy only. I'll test hwy next time I have a long trip.


hummmm :rolleyes: wonder how your getting such GREAT gas mileage? I have nearly the same setup 35 12.5 18.....

hummmm :rolleyes: wonder how your getting such GREAT gas mileage? I have nearly the same setup 35 12.5 18.....

And now some partial scores from the world of major league baseball:

12
16
8
3

Yeah - this mileage thing has been extensively debated. Not sure why some get more and some seem to be really low.

Thanks for bringing this to my attention and somehow I missed this forum. K&N was added few months ago and used about 3,000 miles. It will go out of door in no time. Will go back to AC Delco filter. Uuh... NO. You want to get that TxC CAI from CoolMyDuramax.com and use your stock air intake box with the AC Delco filter. It's been proven to be the hands down best filter for your truck. Read the definitive research here:

http://www.dieselplace.com/forum/showthread.php?t=117009

K&N has an impressive story, and they look good to boot. However, you can easily end up with oil all over your MAF, and then you're gonna wish you'd never even heard of K&N. YMMV...

TxC's CAI added 1-2 MPG to my rig...

I think the most direct way to gain MPG is to get rid of the engine fan.

Rad Mod V2 if you tow with the truck
Electric Fans if you never put more then appx 1500 pounds behind or in it. (still learning this one the hard way)

hummmm :rolleyes: wonder how your getting such GREAT gas mileage? I have nearly the same setup 35 12.5 18.....
I also have the approx. same setup and I am also seeing 17 mixed/20 frwy(hand calc,gps verified). Everything listed in my sig plus I have been using redline diesel fuel catalyst for the last couple months. I definitely know I could get better, but I cant stop putting the foot into it!:rolleyes:

dang! i get 13.5 mixed. going to do the egr soon. i get the same milage whether im drive lightly the whole take or play a little.

If I go the EFI, do I still need to get the EGR blockoff, etc?

If I go the EFI, do I still need to get the EGR blockoff, etc?

Yes... 'cause even though you can turn it off, you can blow the valve open under heavy acceleration. You want to block it... period.

All you guys are lucky. 11.8 since the day it drove off the lot. Unlaoded. I pushed 13 on the highway a few times unloaded.....

I've been averaging 17.6 and 19.1 per the DIC at 75mp with the tach at 2200... bone stock! I guess I'm lucky.

I saw 17-18mpg city/ 21-22mpg highway with my truck on 33's, and the same now that it's on 32's. Those are the unloaded ratings though. With about a 5000lb+/- load I still see upper-teens on the highway and mid-teens in the city.

Tom

I just recorded my best mileage to date.

290 miles indicated on the trip meter, 14.2gal used. But this is with stock gearing, no programmer, and 35x13.5x20" tires.

When you factor in the larger tires it comes out to something like 335 miles, which is a real world 23.6mpg :eek: :D

Tires were at 55psi front, 50 rear, all synthetic fluids, stock exhaust and no programmer. Stranadyne performance additive in the fuel, and I kept it at a real 65mph, which is around 57 indicated on the speedo, and cruise control set 90% of the time, no AC.

It can be done, seems speed SERIOUSLY effects the mileage these things get. Slow it down and mileage goes up considerably. Guys with 5spd trucks, throw on taller tires, it helps on the highway.

I used to get lower mileage but after towing the 5th wheel out to Seattle and back I do much better now. You just need to get some miles on the truck (not necessarily towing) before it gets broke in.

My neighbor who drives a Dodge always told me about his fantastic mileage. When I explained my situation, he said just wait it will get better about 40K miles.

I am still not quite there but I have seen a significant increase in mileage now that I am about 34K...

My mileage was always 15-16 no matter where i went empty. I just recently started getting better mileage, im now at 19-20 I just drive between 60-65 with no cruise. Its been a good 3-4 months since I've gotten on it at all. Im wandering if mileage increases as you go longer without getting on it due to the addaptive learning. I also went back to 265s instead of 285s and have seen a small increase since then.

QUOTE "K&N has an impressive story, and they look good to boot. However, you can easily end up with oil all over your MAF, and then you're gonna wish you'd never even heard of K&N."


I hear that same story about K&N filter oil all of the time and I just don't see it being an issue. I have used them for years with 0 problems. I have had one on my 05 lly since new, currently have 60K miles. again no issues. When I was a dealer tech, I installed one in a used car with 50K miles on it that a fellow tech was buying. When he junked the car at 600K miles because of hitting a deer, it still had that same filter in it with the original MAF!

As a tech, I could fill a large house with bad MAF sensors that had nothing to do with K&N or any other brand of filter. Most of the time it is an issue with of not wanting to cover the part under warranty and looking for a scape goat I think.

The stealers not only steal from consumers, they are making it tough on the techs to make a living. Most HATE doing warranty work because it pays so little.

My hummble opinion!

I have an 05 lly with 5" straight pipe and egr blocked and can't get any better than 15 to 16.5 hand calc. wanting to get it programed by so-cal for milage. my 06 cummins gets 19 to 22 no matter how you drive it. but this duramax will woop up on it in a race :D

I drive my truck pretty hard but I've only seen 20 mpg once and that was driving on flat ground and never going over 60 and it was 100% freeway. Based on what everyone is saying they are getting 500-700 miles per tank........

i might get 450 miles if i ignore the low fuel light.

What is the best programmer for mileage?

Everyone has their own idea- however, I believe the PPE Standard is one of the best and much safer on the trans. Only set it on 2 and your mileage will improve- guaranted by PPE. :D ANything higher than 2 will limp the tranny. Then it is time for a big buck rebuild.:(

Are people experiencing tranny problems with these programmers, if so what type of problems?

It all depends.....lots of reading to do with many facts and opinions. I suggest you search on the Allison aftermarker threads.

Are people experiencing tranny problems with these programmers, if so what type of problems?

Hello everyone. I just purchased a 2005 2500 4wd 4 door duramax. I love the truck, and currently get around 15 mpg. Im leaving the tires and and height stock, but would like to do a couple mods to up the mpgs.

Ive read about the cai from keepmyduramaxcool.com and plan on it.

2nd, i want to do the egr block off, and this being an 05, ill need the fingerstick, correct? Where do i find the fingerstick and the template for the block off plate, ill make that myself.

Next, where is the best pcv re route kit?

What is the best programmer for mileage?

Sean
Either there is something wrong with your truck, or it's your driving habits. I get over 20mpg's on the highway driving around 60mph, and about 16.5mpg city. I take my sweet time accelerating.
Anything else anyone here can think of, besides keep your foot out of it, lol, please share. Thanks, ive done alot of reading on this site, and everyone here seems very knowledgeable.

The best thing I have done so far for mileage is getting rid of the darn cat, when I bought my d-max it had a 5" cat back and I just added a 4" front pipe (cheap mod) and my mileage jumped at least 2 mpg. Did the boost stick at the same time but it just seems to breath so much better and sounds better to.

This has been beat to death many times. I get 14mpg on the highway empty and 9-10 mpg when towing a 27' TT. I don't expext anything good when I'm towing because I still drive 75 mph. But empty it has always only ever been 14 mpg no matter what mod I have done. I've given up hope and just plan on stopping every 300 miles at the most.

isn't the egr blocker plate from kennedy like $10? Just buy it, aint worth the time to make it, IMO

lately, I'm paying more attention to the fuel quality.

some fuel burns very well, and some does not.

Furthermore, I can tell if I have good fuel based on the fuel consumption at idle, out of gear.

Also, and here is the fun part, If I add power service diesel kleen to the tank, I can make bad fuel burn well.

The difference between good and bad fuel is 15% or so - that's my best guess. (although, it seems that around town mileage is more affected by bad fuel than highway mileage)

I have only had this truck for a couple of weeks but so far I am averaging 15-16 around town (35-50 MPH) and about 18 MPG on the highway. This is using my GPS to correct for tire size, I have 285's on it. This is so much better than my 08 gasser that only got 11 MPG. :eek:

This has been beat to death many times. I get 14mpg on the highway empty and 9-10 mpg when towing a 27' TT. I don't expext anything good when I'm towing because I still drive 75 mph. But empty it has always only ever been 14 mpg no matter what mod I have done. I've given up hope and just plan on stopping every 300 miles at the most.

Well, if you have any lift to that truck to account for the 285's, you can figure that you're not going to do much better than that. The bigger tires and getting the truck up in the air (not to mention driving 75) is gonna keep you from getting much better.

Keeping the stock tires, keeping it closer to the ground, and keeping it closer to 2k rpm will improve your mileage considerably. BTW, are you compensating for those bigger tires in your mileage?

If you like the truck as it is, then the mileage is what it is. :rolleyes:

I have a 05 lly with 5" straight exhaust,egr blocked and the best i have ever got out of mine is 17.5 driving only 62 on flat interstate. I do have bars cranked up and 20's with 275/65/20 street tires

i have a 05 lly cc sb with 285's, bully dog programmer, no muffler, stock filter, and exhaust. i used standedyn, and i use this green powder from BPI products. i am getting 24-26mpgs on the hwy and 19-22 city. since i started using the powder. it works awesome!!!

I have a completely stock 04 LLY, 4x4, crew cab short box.

I'm happy with the performance today. I got
9.9 litres/100km
or
23.8 US MPG / 28.5 Imp. MPG

For the first time ever, I got 400 km on the first 1/2 of the tank. No cruise control, all manual. I think CC costs at least 10%

My speed was averaging 96 km/hr, around 60 mph, slower than most drive I know.

cheers.

I think you can spend a lot of time and money doing mods and risk having problems with the warranty.

Or you can just wait until you get the truck broke in @ about 40K miles and re-evaluate the situation. Some of it is the way you drive - keep in under 2,000 RPM but one thing that goes unnoticed is that nobody says how many miles there are on the truck when they state mileage figures. It took me awhile but you need to get the mileage/break-in done before you can really get good MPG.

Some people claim better mileage due to tuners and stuff but you still have to drive like a grandma. Just be patient...

Driving conservatively I got 15-16 in town with a 5" and predator. Towing my 8k camper about 10, much less at 80mph.

Driving conservatively I got 15-16 in town with a 5" and predator. Towing my 8k camper about 10, much less at 80mph.

Fill out your sig so we can see how your rig is configured... and what tune do you use when you tow?