Gas Mileage Question

MVP9182 · July 21, 2016

I know this is topic has been gone over thousands of times, but the gas mileage on the 2500HD 6.0L is terrible! The previous owner had put on a cold air intake so it had that going for it. The old, bald tires he had on there were Mastercraft Courser C/T 285s. I went ahead and put on Toyo Open Country AT2s 265s. The majority of my driving is highway driving with the AC on, but I do my fair share of offroading in the corn fields with 4x4, and on the super hot days I have to sit with the truck running so I can get AC so I know that's not helping much. After my last fill up I was getting 11.8 mpg. Is there anything I can do to help this out? New spark plugs and wires? New muffler? I know tunes are supposed to help but I don't have the money to drop on that unfortunately.

sdeeter19555 · July 21, 2016

That's pretty much what I get with my 2012, not much going to help it...a tune maybe, but not enough savings so offset the cost of the tuner.

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MVP9182 · July 21, 2016

That's pretty much what I get with my 2012, not much going to help it...a tune maybe, but not enough savings so offset the cost of the tuner.

That's always been my issue with tunings. They don't help that much so you'd have to drive it a lot to really get your money back out of it. I've heard of people putting on electic fans. Would that help at all?

Formulabruce · July 21, 2016

IMHO..

1. A Road tire ( M&S WITH GROOVES in it and small to no side treads) will help ( I run Michellin )

2. While it may be hard to find these days, I use a Mileage XS Super tuner. I adjusted the speedo for the 265 Michelin tires

I adjust the Up shift for all the gears to as low as possible, getting it all in and Locked up at like 49 mph under normal driving.

3. Keep my air pressure at 60 lbs, vs the max of 90 for the E rated tires.

4. Run STOCK Cold air ...Air Cleaner . It is a COLD air intake set up and for a truck its fine and works well and doesnt allow more too much air, then it would want more fuel.. These after market $$$cold air intakes are just $$ money burnt on a truck made for Torque..

5. I get 14 mpg normal, and I can get as high as 17 on the highway at 65 mph or under and steady and empty. I get 12 with AC and around town... I have 4.11 gears and a G80 out back

O_J_Simpson · July 21, 2016

Trade it in. You bought the wrong truck if fuel mileage is any concern at all.

Cowpie · July 21, 2016

Any concern at all? Should I trade in my class 8 semi truck because it averages just 7.93 mpg and I am concerned about getting the best mpg out of it I can? I have a 2500 that I try to get the best mpg I can also. Just because one gets what they need the job they need to do doesn't mean it is stupid of them to try and get the best mpg out of it they can, and put some effort into doing so. On my semi truck, just a simple 1 mpg better means I keep an extra $6000 a year in my bank account. Chump change to some, I know, but I would rather it be in the bank than shoving it out the stacks. My 2500 6.0L doesn't do too bad overall. It has averaged 14 mpg for its lifetime of 24K miles, and the best road trip mpg I got was 18 mpg. Doesn't mean I wouldn't like it to do better and put some effort towards that goal.

Raptordude · July 21, 2016

When I bought my 2001 Silverado 2500HD with the gas 6.0 I was getting 11.7mpg...I recently put a new fuel pump in it. It's an AC delco one, but it's the "new" style. It's much different than the old school 2001 pump. After I did that my around town mileage went to 13.5

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SpartanAutoworx · July 21, 2016

LSA Swap your 6.0 truck that you use every day and then tell me how you feel. lol I dont pass a gas station any more. Im getting ready to swap my other tow rig with a 75mm on three turbo I bet it gets better MPG then the LSA lol

MVP9182 · July 21, 2016

Any concern at all? Should I trade in my class 8 semi truck because it averages just 7.93 mpg and I am concerned about getting the best mpg out of it I can? I have a 2500 that I try to get the best mpg I can also. Just because one gets what they need the job they need to do doesn't mean it is stupid of them to try and get the best mpg out of it they can, and put some effort into doing so. On my semi truck, just a simple 1 mpg better means I keep an extra $6000 a year in my bank account. Chump change to some, I know, but I would rather it be in the bank than shoving it out the stacks. My 2500 6.0L doesn't do too bad overall. It has averaged 14 mpg for its lifetime of 24K miles, and the best road trip mpg I got was 18 mpg. Doesn't mean I wouldn't like it to do better and put some effort towards that goal.

Unfortunately for me I was just trying to replace a red '99 1500 that we had years ago that got totalled. So a red '02 2500HD was the closest I could find so that's what I got. Probably a decision made more with my heart than my wallet and now my wallet is feeling to hurt from it. I knew what I was getting when I bought it though. I'm just trying to make the best out of it.

MVP9182 · July 21, 2016

LSA Swap your 6.0 truck that you use every day and then tell me how you feel. lol I dont pass a gas station any more. Im getting ready to swap my other tow rig with a 75mm on three turbo I bet it gets better MPG then the LSA lol

I have been considering saying screw gas mileage and rebuilding it with a stroker and mild cam. But that definitely turn it into a toy more so than a daily driver lol

sdeeter19555 · July 21, 2016

The main issue with these trucks is that they are quite a bit heavier than a 1500 and they don't have the pressure to maximize the mileage out of them like the 1500s. Just think of the tailgate cap/spoiler on the 1500 that isn't on the 2500/3500.

More power does not necessarily mean worse power if driven easy. I owned an 1986 Dodge Ramcharger at one point, swap a 318 for a mild 440...mileage went from a high of 12 to a high of 17mpg, as long as I stayed out of the secondaries.

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newdude · July 21, 2016

I went ahead and put on Toyo Open Country AT2s 265s. The majority of my driving is highway driving with the AC on, but I do my fair share of offroading in the corn fields with 4x4, and on the super hot days I have to sit with the truck running so I can get AC so I know that's not helping much. After my last fill up I was getting 11.8 mpg.

Idling with the AC is the biggest killer. Near 12 mpg is pretty reasonable for what you are stating for driving habits. How fast do you run on the highways? 55? 65? faster? That will kill it too. 50-60mph is the MPG sweet spot on those 01-07 HD trucks with the 4L80 and 6.0. Keeps the RPM's at 2k or less. The aggressive AT tires? Sure, they factor in but not a whole lot really. What do you run for pressures in them?

I'd stock airbox it with an AC Delco filter. If its got 100k or more on it, some AC Delco plugs.

MVP9182 · July 21, 2016

Idling with the AC is the biggest killer. Near 12 mpg is pretty reasonable for what you are stating for driving habits. How fast do you run on the highways? 55? 65? faster? That will kill it too. 50-60mph is the MPG sweet spot on those 01-07 HD trucks with the 4L80 and 6.0. Keeps the RPM's at 2k or less. The aggressive AT tires? Sure, they factor in but not a whole lot really. What do you run for pressures in them?

I'd stock airbox it with an AC Delco filter. If its got 100k or more on it, some AC Delco plugs.

I try to keep around 60 mph on the highway I drive to and from work on. It runs a little less than 2k rpm. The motor was replaced but should have around 150k miles on it. No clue when the last time the spark plugs were replaced. It didn't seem to do much when I replaced them on my '99 1500 with the 5.3 in it though. That had factory plugs in it after 125k miles! My dad wasn't big on maintaince...