REAL World MPG's

[boss_hog]

Once you own a diesel truck that you actually use as a truck (which it appears you do) you will never be able to deal with a gas truck again. Believe me I have had countless customers try and it never lasted. For one 2.06 vs 2.76 here for low grade gas vs diesel. So for 400 miles you would get a best of $0.113 per mile (400/18.2=21.978 gallons x $2.06=$45.27/400). I would say average for my customers for strictly highway is 22mpg, with many getting more if they try and have a decent setup for mileage. At 22mpg it is 0.125 miles per dollar. I will gladly pay the extra $0.012 per mile to drive a that pulls like nothing is behind it, has 425 rwhp and 800 ft lbs with a simple tune, and will last a half million miles if taken care of properly.

Towing you got 8.4mpg so it would be $0.245 per mile. A load like that I would normally get 13mpg so $0.212 per mile. So any time I am towing not only do I have a trans meant for it and the torque and power to not notice it, but it cost me less per mile. The price isn't just the engine, it's the Allison trans, trans cooler, etc that comes with it.

I know a lot of people with duramax and Cummins closely. Some farmers, demolition contractors, manufacturer business and some who just use them for there offshore rigs. All of them tell me the same thing that somebody saying they get 20mpg is lying. The ones with 35" tires never got over 16, Cummings more like 15 if driven like a baby. I really trust these people to be telling me the truth because as well as I know them. One has a boat that is very similar in weight, size and shape. He gets 12.5 pulling it around 60mph and 17-18 unloaded with stock 265 tires non mud grips with a 2012 Duramax cc/sb 4x4. I don't doubt that they will Last 500000 with some maintenance but in my fleet of service trucks i have many gassers 1/2 ton and 3/4 tons with 300-400k right now that run great. I would love to tow with one and do believe that the next service truck I buy will have a duramax. But one thing I will say about towing is a lot of people jump straight from a 1/2 ton gas to a 3/4 ton diesel and say it's a phenomenon but so is going from a 1/2 ton to a 3/4 ton gas. I'm sure the torque difference will be undeniable on a 6% grade towing 20000# but not everyone will tow something like that ever. The heaviest I'm worried about is a 580k backhoe and the gooseneck which is right around the 20k
mark. It will be a lot less wind resistance than the tt or boat so that should help but honestly I don't feel my boat behind the truck until I'm around 75 mph that's when the truck gets noticably slower,still don't feel it in the suspension. I need to pull the backhoe over the mountains because I refuse to drive my dump truck that far. So we'll see how it handles it.

 

[WolfLMM]

Boats are a different animal buddy. They have huge bows and t tops that act like sails. My old Denali quadrasteer with a 6.0 got 4.4 mpg pulling my 26 footer. I took it to key west once and had to stop every 80 miles to fill it up...:roflmao:

Hey Wolf, you going to Key West yourself to fish the sail tourney?

Holy old thread!

 

[NC-smokinlmm]

Holy old thread!

Just saw that. Lol..

Like 4 years old... Haha...

 

[WolfLMM]

Btw, I pulled that boat with a 3500 dodge, boy I'm not sure why I ever complained about my LMM

And nope, I'm not fishing any tourneys, to damn broke right now. Must work

 

[othrgrl]

I know a lot of people with duramax and Cummins closely. Some farmers, demolition contractors, manufacturer business and some who just use them for there offshore rigs. All of them tell me the same thing that somebody saying they get 20mpg is lying. The ones with 35" tires never got over 16, Cummings more like 15 if driven like a baby. I really trust these people to be telling me the truth because as well as I know them. One has a boat that is very similar in weight, size and shape. He gets 12.5 pulling it around 60mph and 17-18 unloaded with stock 265 tires non mud grips with a 2012 Duramax cc/sb 4x4. I don't doubt that they will Last 500000 with some maintenance but in my fleet of service trucks i have many gassers 1/2 ton and 3/4 tons with 300-400k right now that run great. I would love to tow with one and do believe that the next service truck I buy will have a duramax. But one thing I will say about towing is a lot of people jump straight from a 1/2 ton gas to a 3/4 ton diesel and say it's a phenomenon but so is going from a 1/2 ton to a 3/4 ton gas. I'm sure the torque difference will be undeniable on a 6% grade towing 20000# but not everyone will tow something like that ever. The heaviest I'm worried about is a 580k backhoe and the gooseneck which is right around the 20k
mark. It will be a lot less wind resistance than the tt or boat so that should help but honestly I don't feel my boat behind the truck until I'm around 75 mph that's when the truck gets noticably slower,still don't feel it in the suspension. I need to pull the backhoe over the mountains because I refuse to drive my dump truck that far. So we'll see how it handles it.

Sounds like they are all talking about bone stock trucks that are choked out with emissions crap and wasting fuel to clean the filters that choke them in the first place. On a 6.7L Cummins you can pick up about 3-5mpg by doing an exhaust and tuner. If you do an intake and intake elbow you will be more likely to get the full 5mpg gain. Not to mention that you can add horse power and torque while you gain mileage. On a 2007.5-2010 LMM Duramax it is similar results. 2011 and newer don't have quite as much to gain so easily, but they are easy to get over 20mpg out of, and many guys do stock. When I say don't know it's back there I mean you can accelerate like it is not there and the transmission doesn't feel all sloppy with a load. A 6.0L gas with a 4L80 just doesn't compare, even the 8.1L doesn't compare because of the lack of torque. The biggest thing to me is that with a cam, heads, tuning, headers, exhaust, intake, etc you can't get out of a gas what we can with a conservative tune on a diesel - and you'll lose mileage as you add power, while we'll gain mileage.

Either way, if you love your 6.0L gas trucks, that is great but you are on the wrong site and need to go over to gmfullsize.com to find a few people that agree.

 

[boss_hog]

Bahahaha!! No need for anyone to have waded panties just giving some comparisons like everyone else. Like I said I have been considering purchasing diesels. But either way the last thing I will do is add and change stuff where it pushes the drive train too far then off to the repair shop. If it was just that easy to get big gains with no damage don't you think the manufacturers would have figured that out and did it to get the advantage on the competitors? Over half of the people I know have tuners and exhaust. The same people i was referring to. One has had 3 new rams in the last 11 years with a bully dog in the first 2. Just mentioning all the repairs he has had would take all day. He probably doesn't remember all of them. Those trucks have been back to the dealer as much as he has had them. Transmissions at 8k, 30k, 56k and so on. Engine failure as low as 22k. I'm not interested in that. It should perform out of the box. Will a guy that pulls 2 lawnmowers and 3 weeders benefit from a diesel, no. Someone that pulls delivering 15-20k for a living heck yeah. Someone that pulls a camper 2-3 times a year 1000 miles no. A bunch of people buy diesel now for the same reason so many buy iPhones, because everyone else is doing it and it's popular. People trash the 6.0 without even knowing what it can do way too much or lie about ever having one. I am in the middle of the needs. I pull heavy loads often but not extreme loads. Will save enough in under 100k before I trade it in, no. But if for some unseen reason I start pulling the extreme loads often then it would be there if I need it if it pulls so much better than gas. At the same time most of my loads are on flat ground. So if I integrate a duramax are 2 in my work vehicles they will be there if I need it. Btw the dump truck is diesel but it flares my back problems on long drives. It gets a whopping 4-6 mpg pulling empty with the backhoe in tow and the same mileage loaded with topsoil

 

[WolfLMM]

My 2001 lb7 has 300k on the clock, 180k at or over 600hp buddy. It's only needed injectors. Don't even play around like GM gassers don't have problems.

 

[WolfLMM]

Btw, I'd love to see a 6.0 pull my new boat. I bet it would rarely see anytime below 4000 rpms

 

[boss_hog]

My 2001 lb7 has 300k on the clock, 180k at or over 600hp buddy. It's only needed injectors. Don't even play around like GM gassers don't have problems.

Did I say something negative about duramax trucks. That was a Ram. I will never buy one of those, seen them with too many problems. I have never had engine failure with any gm products made after 2000 with up to 400k on them

 

[boss_hog]

Sounds like they are all talking about bone stock trucks that are choked out with emissions crap and wasting fuel to clean the filters that choke them in the first place. On a 6.7L Cummins you can pick up about 3-5mpg by doing an exhaust and tuner. If you do an intake and intake elbow you will be more likely to get the full 5mpg gain. Not to mention that you can add horse power and torque while you gain mileage. On a 2007.5-2010 LMM Duramax it is similar results. 2011 and newer don't have quite as much to gain so easily, but they are easy to get over 20mpg out of, and many guys do stock. When I say don't know it's back there I mean you can accelerate like it is not there and the transmission doesn't feel all sloppy with a load. A 6.0L gas with a 4L80 just doesn't compare, even the 8.1L doesn't compare because of the lack of torque. The biggest thing to me is that with a cam, heads, tuning, headers, exhaust, intake, etc you can't get out of a gas what we can with a conservative tune on a diesel - and you'll lose mileage as you add power, while we'll gain mileage.

Either way, if you love your 6.0L gas trucks, that is great but you are on the wrong site and need to go over to gmfullsize.com to find a few people that agree.

07 up doesn't have the 4l80 in 2500HD models

 

[boss_hog]

Btw, I'd love to see a 6.0 pull my new boat. I bet it would rarely see anytime below 4000 rpms

What boat at what speed at what grade. On pavement or dirt. I only hit 4000 with my tt and tools when passing a Ford up 6% at 75mph

 

[WolfLMM]

40ft long 10'9" beam 19,000 pound center console. That's all my duramax wants, I couldn't imagine trying to pull it with a gasser. It would be an awful experience I'm sure.

 

[boss_hog]

40ft long 10'9" beam 19,000 pound center console. That's all my duramax wants, I couldn't imagine trying to pull it with a gasser. It would be an awful experience I'm sure.

That's bigen. The biggest I've pulled is a 32'. I bet that boat gets multiple gallons to the mile. Did you ever hit s top speed with the boat in tow?

 

[LWATSON]

Once you own a diesel truck that you actually use as a truck (which it appears you do) you will never be able to deal with a gas truck again. Believe me I have had countless customers try and it never lasted. For one 2.06 vs 2.76 here for low grade gas vs diesel. So for 400 miles you would get a best of $0.113 per mile (400/18.2=21.978 gallons x $2.06=$45.27/400). I would say average for my customers for strictly highway is 22mpg, with many getting more if they try and have a decent setup for mileage. At 22mpg it is 0.125 miles per dollar. I will gladly pay the extra $0.012 per mile to drive a truck that pulls like nothing is behind it, has 425 rwhp and 800 ft lbs with a simple tune, and will last a half million miles if taken care of properly.

Towing you got 8.4mpg so it would be $0.245 per mile. A load like that I would normally get 13mpg so $0.212 per mile. So any time I am towing not only do I have a trans meant for it and the torque and power to not notice it, but it cost me less per mile. The price isn't just the engine, it's the Allison trans, trans cooler, etc that comes with it.

Dustin, remember the eco tune I tested for you a few years ago? I got 24.5 mpg hwy. It wasn't a responsive tune but I still turned an 8.04 in the 1/8th with it. Still had 4 other tunes to choose from depending on my needs. I own a gasser also, I daily drive it but if I have to tow over 20 miles I pull the Dmax out of the garage.

 

[othrgrl]

For one you talk about Rams with trans issues... big surprise there, LOL. Then you mention Bully Dog - I wouldn't put a Bully Dog on a Scooter if you gave me both of them. I also do custom tuning on GM gas engines including the LQ9 6.0L that comes in the SS, Escalade, Denali, GMC VHO, and VortecMax trucks and the weaker LQ4 that came in the 1500HD, 2500, 2500HD, 3500 (your trucks) and up and am aware of what they are capable of. I have also built, rebuilt, and modified gas engines since before computer controlled diesels were in trucks. I have had quite a few customers who started to think they didn't need a diesel, for the reasons you've listed so they sold it or traded it for a 6.0L or 6.2L truck and the first time they towed with it they got home and put a for sale ad up on the gas truck.

Could GM up the power from the factory, yes and they do when they are torture testing any new changes. Thing is they have to turn them down enough for the biggest idiot with the heaviest foot and the worst maintenance habits to still have one last 100,000 miles so that they don't have to come out of pocket to fix it under warranty. Do you put larger than 245-75R16 tires on anything you've owned? Oh no, the powertrain can't handle it, better head to the repair shop... come on. Are there limitations on certain components, of course and that is why I said 425 rwhp with a tune - that is the highest that is safe on a stock 6 speed Allison. With tuning alone we can hit 500rwhp on 06-10 trucks, but it's not safe on the transmission. With a transmission that is beefed up to handle it I have guys that have put hundreds of thousands of miles on their trucks with over 500 rwhp without hurting anything else. Like I said if you like your gas trucks and they do what you need that is fine, I just don't understand why you would join a site called "Duramax Diesels" to post up in a 4 year old thread that you are happy with your decision to stick with another gas truck; and especially why you would be surprised when we have this reaction:roflmao:.

Landon, I do remember that and I remember the trash that was talked about it not being a mileage tune when you posted up what it had run.

 

[boss_hog]

For one you talk about Rams with trans issues... big surprise there, LOL. Then you mention Bully Dog - I wouldn't put a Bully Dog on a Scooter if you gave me both of them. I also do custom tuning on GM gas engines including the LQ9 6.0L that comes in the SS, Escalade, Denali, GMC VHO, and VortecMax trucks and the weaker LQ4 that came in the 1500HD, 2500, 2500HD, 3500 (your trucks) and up and am aware of what they are capable of. I have also built, rebuilt, and modified gas engines since before computer controlled diesels were in trucks. I have had quite a few customers who started to think they didn't need a diesel, for the reasons you've listed so they sold it or traded it for a 6.0L or 6.2L truck and the first time they towed with it they got home and put a for sale ad up on the gas truck.

Could GM up the power from the factory, yes and they do when they are torture testing any new changes. Thing is they have to turn them down enough for the biggest idiot with the heaviest foot and the worst maintenance habits to still have one last 100,000 miles so that they don't have to come out of pocket to fix it under warranty. Do you put larger than 245-75R16 tires on anything you've owned? Oh no, the powertrain can't handle it, better head to the repair shop... come on. Are there limitations on certain components, of course and that is why I said 425 rwhp with a tune - that is the highest that is safe on a stock 6 speed Allison. With tuning alone we can hit 500rwhp on 06-10 trucks, but it's not safe on the transmission. With a transmission that is beefed up to handle it I have guys that have put hundreds of thousands of miles on their trucks with over 500 rwhp without hurting anything else. Like I said if you like your gas trucks and they do what you need that is fine, I just don't understand why you would join a site called "Duramax Diesels" to post up in a 4 year old thread that you are happy with your decision to stick with another gas truck; and especially why you would be surprised when we have this reaction:roflmao:.

Landon, I do remember that and I remember the trash that was talked about it not being a mileage tune when you posted up what it had run.

Wow!! With that explanation it's amazing they make a camero, corvette any performance vehicle for that matter. Lookout 6.2 vehicles that's borderline hp ratings for the mighty Allison with an inferior transmission . Keep pondering why I joined since you haven't figured it out yet. Btw Chevy taunts at least 200000 miles of heavy work with the 6.0. Speaking of the 6.2, the z06 version 650hp 650 ft tq. Now that would be interesting in a 3/4 ton. I know my way around engines too. I've built gas and tractor diesels. I have a 1979 k10 with a 389 stroker I built 3 spd with granny I have towed loads that scared many just see it hooked behind it. It was geared like crap 3:08 running 33's. I couldn't keep a drive shaft on it. Got 10 mpg no matter if it was empty or towing a 690 e trackhoe. In 2000 I hooked bumpers to a brand new Ram diesel he locked his in 4 wheel drive after the first pull was so terrible while I stayed in 2h and i drug that until he blew a tire. It was awful. But that is a different league of engines. I've built dirt track engines up to assisting with top fuel. Nowadays I just want to buy something I'm confident in and will not ignore when both products are doing well. I'm happy for gm with the duramax because the previous diesels were a joke

 

[othrgrl]

Wow!! With that explanation it's amazing they make a camero, corvette any performance vehicle for that matter. Lookout 6.2 vehicles that's borderline hp ratings for the mighty Allison with an inferior transmission . Keep pondering why I joined since you haven't figured it out yet. Btw Chevy taunts at least 200000 miles of heavy work with the 6.0. Speaking of the 6.2, the z06 version 650hp 650 ft tq. Now that would be interesting in a 3/4 ton. I know my way around engines too. I've built gas and tractor diesels. I have a 1979 k10 with a 389 stroker I built 3 spd with granny I have towed loads that scared many just see it hooked behind it. It was geared like crap 3:08 running 33's. I couldn't keep a drive shaft on it. Got 10 mpg no matter if it was empty or towing a 690 e trackhoe. In 2000 I hooked bumpers to a brand new Ram diesel he locked his in 4 wheel drive after the first pull was so terrible while I stayed in 2h and i drug that until he blew a tire. It was awful. But that is a different league of engines. I've built dirt track engines up to assisting with top fuel. Nowadays I just want to buy something I'm confident in and will not ignore when both products are doing well. I'm happy for gm with the duramax because the previous diesels were a joke

I'm not talking about crank horsepower numbers and I'm talking about in a 7,000 truck empty, not a car that weighs half as much. Of course even a "almighty" Allison that was spec'd for 365 crank hp and work, pulling, and normal driving type use has issues with nearly doubling the power and then drag racing. Stay within the power I mentioned (which is WAY above what a LQ4 makes, like 1.70 times more power and 2.7 times the torque) and the Allison will do perfectly fine. GM holds back some even on their performance cars for warranty reasons and they over-charge enough for them to cover the repairs under warranty anyway. I bet the COPO Camaros come with a 0 month 0 mile warranty since they are a production race car holding nothing back. Besides 90% of Corvette owners are 50+ years old and a little gentler on their cars than most.

A 6 speed Allison in perfect shape can have a few things done to it relatively cheaply to handle the full potential of the motor. With a lift pump and tuning we can easily do 540-550 hp at the tire (estimated 690 at the crank) and 1050 ft lbs of torque at the wheels (1300+ at the crank) and run mid to low 12s in a CCSB daily driver. I would gladly line that up beside a 3/4 ton with a 6.2L Corvette motor. Hell, I've lined mine up against numerous Z06 Corvettes at the track and embarrassed them.

Never mentioned resale, but I bought my 05 for $25,000 in 2007 when it was 2 years old and had under 60K on it. I see people paying $23-25K for 2005 trucks with over 100K miles on them in good shape, mine has just under 100K on it and in great shape and is still worth what I paid for it almost 8 years ago. 2001s with over 200,000 on them will still get $15,000. A running driving Duramax of any year and mileage will not last a day on craigslist if it is under $10K - literally my retired dad keeps a close eye on craigslist and calls me about any deals that I can flip and I'll call 3 hours after one is posted on a Sunday and it will be gone.

 

[moparkxracer]

I find that I get better mileage with more power it makes as long as I keep my foot off the floor.. I will never go back to a gas truck, I find it extremely funny when people with Cameos and corvettes get their feelings hurt when the try to play with me.

 

[boss_hog]

I'm not talking about crank horsepower numbers and I'm talking about in a 7,000 truck empty, not a car that weighs half as much. Of course even a "almighty" Allison that was spec'd for 365 crank hp and work, pulling, and normal driving type use has issues with nearly doubling the power and then drag racing. Stay within the power I mentioned (which is WAY above what a LQ4 makes, like 1.70 times more power and 2.7 times the torque) and the Allison will do perfectly fine. GM holds back some even on their performance cars for warranty reasons and they over-charge enough for them to cover the repairs under warranty anyway. I bet the COPO Camaros come with a 0 month 0 mile warranty since they are a production race car holding nothing back. Besides 90% of Corvette owners are 50+ years old and a little gentler on their cars than most.

A 6 speed Allison in perfect shape can have a few things done to it relatively cheaply to handle the full potential of the motor. With a lift pump and tuning we can easily do 540-550 hp at the tire (estimated 690 at the crank) and 1050 ft lbs of torque at the wheels (1300+ at the crank) and run mid to low 12s in a CCSB daily driver. I would gladly line that up beside a 3/4 ton with a 6.2L Corvette motor. Hell, I've lined mine up against numerous Z06 Corvettes at the track and embarrassed them.

Never mentioned resale, but I bought my 05 for $25,000 in 2007 when it was 2 years old and had under 60K on it. I see people paying $23-25K for 2005 trucks with over 100K miles on them in good shape, mine has just under 100K on it and in great shape and is still worth what I paid for it almost 8 years ago. 2001s with over 200,000 on them will still get $15,000. A running driving Duramax of any year and mileage will not last a day on craigslist if it is under $10K - literally my retired dad keeps a close eye on craigslist and calls me about any deals that I can flip and I'll call 3 hours after one is posted on a Sunday and it will be gone.

Trucks are getting rather rediculously priced these days as I paid 26000 new for 2010 half ton and got 25000 out of it 4 years later with 42000 miles. So you have one of those 3 seconds 0-60 duramax that I see on YouTube?

 

[Firefightkev]

I had an LB7 which was fantastic for mpg. Went to the Florida panhandle doing 70-90 mph and still got 19.5 mpg which was hand calculated. I have an LLY and at 70 mph i can get 17.5 average. Even towing in the LLY wasn't that bad. Towed a 24ft travel trailer around 5000lbs at around 65 - 75 and still got 11.9 mpg. But I do live in Florida so its not like we have a bunch of hills. I should have never sold my LB7.