Mpg On 6.0

Kodiak450 · October 20, 2009

Ok, last fill up I decided to figure out what I am getting for mpg, so I set the trip to 0.0. I always ran till 1/2 tank was empty then filled it back up. Anways I had 287 on my trip before i went to fill it up today which took 26.0 gallons. Filled it with 89. So I am getting only 10 mpg. I did have a doctors appointment today which is like 55 miles away from my home and was being a lead foot on the highway going over 80, but for the last year i felt my truck was being a pig and now I know. And to think, my prior plow truck I was using before this one was an F250 and was worse on mileage. I assumed the F250 got 10 mpg, and when I got this truck I noticed it was better on fuel economy just by a little bit more. So I guess the F250 was getting only 8 tops then. My BMW X5 is a heavy SAV and has an inline 6 and that vehicle is great on gas compared to my truck imo.

So I am wondering. I saw an older thread here once where people posted they were getting 15 or more mpg with their 6.0's, so maybe it's the tires I always use? The BFG AT's. They are more aggressive and a heavier tire then the stock tires that came with my truck. Matter of fact, every since I took off the stock tires and put on the BFG's that is when I noticed the mileage was much worse. I had to be getting 12 mpg or better with the stock tires easily. Thinking about maybe getting another set of rims and use diffferent tires on the truck when it's not winter. The gas I save would eventially pay for the wheels and tires over time.

Kenbow · October 20, 2009

Ok, last fill up I decided to figure out what I am getting for mpg, so I set the trip to 0.0. I always ran till 1/2 tank was empty then filled it back up. Anways I had 287 on my trip before i went to fill it up today which took 26.0 gallons. Filled it with 89. So I am getting only 10 mpg. I did have a doctors appointment today which is like 55 miles away from my home and was being a lead foot on the highway going over 80, but for the last year i felt my truck was being a pig and now I know. And to think, my prior plow truck I was using before this one was an F250 and was worse on mileage. I assumed the F250 got 10 mpg, and when I got this truck I noticed it was better on fuel economy just by a little bit more. So I guess the F250 was getting only 8 tops then. My BMW X5 is a heavy SAV and has an inline 6 and that vehicle is great on gas compared to my truck imo.

So I am wondering. I saw an older thread here once where people posted they were getting 15 or more mpg with their 6.0's, so maybe it's the tires I always use? The BFG AT's. They are more aggressive and a heavier tire then the stock tires that came with my truck. Matter of fact, every since I took off the stock tires and put on the BFG's that is when I noticed the mileage was much worse. I had to be getting 12 mpg or better with the stock tires easily. Thinking about maybe getting another set of rims and use diffferent tires on the truck when it's not winter. The gas I save would eventially pay for the wheels and tires over time.

My math gets you 11.03 mpg, thats probably about right if you drive heavy footed.

Kodiak450 · October 21, 2009

Ok, last fill up I decided to figure out what I am getting for mpg, so I set the trip to 0.0. I always ran till 1/2 tank was empty then filled it back up. Anways I had 287 on my trip before i went to fill it up today which took 26.0 gallons. Filled it with 89. So I am getting only 10 mpg. I did have a doctors appointment today which is like 55 miles away from my home and was being a lead foot on the highway going over 80, but for the last year i felt my truck was being a pig and now I know. And to think, my prior plow truck I was using before this one was an F250 and was worse on mileage. I assumed the F250 got 10 mpg, and when I got this truck I noticed it was better on fuel economy just by a little bit more. So I guess the F250 was getting only 8 tops then. My BMW X5 is a heavy SAV and has an inline 6 and that vehicle is great on gas compared to my truck imo.

So I am wondering. I saw an older thread here once where people posted they were getting 15 or more mpg with their 6.0's, so maybe it's the tires I always use? The BFG AT's. They are more aggressive and a heavier tire then the stock tires that came with my truck. Matter of fact, every since I took off the stock tires and put on the BFG's that is when I noticed the mileage was much worse. I had to be getting 12 mpg or better with the stock tires easily. Thinking about maybe getting another set of rims and use diffferent tires on the truck when it's not winter. The gas I save would eventially pay for the wheels and tires over time.

My math gets you 11.03 mpg, thats probably about right if you drive heavy footed.

Made a typo, it is 26.6 not 26.0. I rounded it off to 26.6 from 26.586. Comes out to 10.795155, close to 11 though.

RJG183SA · October 21, 2009

My current tires are Goodyear Silent Armor 285/75/16 E. Two weeks ago I tried to milk the most mileage I could. All local driving no highway. I tried to maintain rpms below 2000 when ever possible. I got just over 13 mpg. Maybe you got some of that lovely winter gas.

My truck has a tune that requires 91+ octane and a 4.10 axle.

hockeypro1411 · October 21, 2009

I can squeeze out 10 if I'm real careful. Last week I did A LOT of hot rodding, couple trips to the mud bog, and generally driving like an ass. I hand calculated it today to be 5.945. I don't regret any of it.

HDcarpenter · October 21, 2009

On the highway I averaged 15 for a while, now I'm down to 13 is and 10ish if I'm hauling. I have a throttle body spacer, which didn't really do much, stock size tires running on 85/87 octane gas provided by my job.

Prokopchuk_9 · October 21, 2009

I can squeeze out 10 if I'm real careful. Last week I did A LOT of hot rodding, couple trips to the mud bog, and generally driving like an ass. I hand calculated it today to be 5.945. I don't regret any of it.

ahahahah that's hilariuous. I wouldn't regret it either hahaha. I get like 10/15 with bigger tires and big rims. I have a heavy foot too. That's on a efi live tune done myself. With 91 octane tune. Advanced timing, and shut EGR valve off. With 3:73 rear end.....it does okay. Better than my buddies dodge hemi!!!!!

RJG183SA · October 21, 2009

On the highway I averaged 15 for a while, now I'm down to 13 is and 10ish if I'm hauling. I have a throttle body spacer, which didn't really do much, stock size tires running on 85/87 octane gas provided by my job.

The only way that throttle body spacer reduced your fuel consumption is by lightening your wallet.

bersh · October 21, 2009

My long term average with my 2004 CC SB, not including plowing or towing, is about 12.5 overall and just over 14 on the highway. There's a big difference between driving 60 and 70 on the highway, probably about 4mpg, and probably another 2-3mpg difference going 75+.

I'm running 265/75 Cooper ATR, have a diamondback tonneau, and have been known to have a heavy foot.

I typically get about 9-10 mpg in the winter including normal plowing (I plow my 300'+ driveway and a couple others and I drop the plow whenever possible).

Kodiak450 · October 21, 2009

Maybe I would of gotten a little better had I not been going over 80 on the highway yesterday. I know when exceeding 75 it gets more thirsty. I'm really convinced it is the bigger heavier BFG tires that take away mpg's. I'm now considering getting 17's with a 285 70r normal looking tire in an E range. Use these wheels and tires for Spring, Summer, Fall, then take them off and throw the stock wheels with the BFG's for winter snow plowing. IDK, I was messing around tirerack.com last night and found a really cool all black teflon rim made by American Racing which is going for $169 for a 17". This is starting to sound more like an excuse to buy, rather for them to pay for themselves over time. But on a serious note, we should be getting at least 400 miles a tank, and I think not having BFG's on will get me back closer to that number, instead of only 287. Could also be my cat back exhaust for poorer mileage. I did notice a little more power after it was on, maybe that knocked a mile or two off the mpg's.

I guess it is a safe statement to say that ever since that exhaust went on, I am more of a lead foot as I enjoy listening to the aggressive rumble that it makes. I can probably improve the mileage if I drove the truck like an old lady, but it is hard for me except when I am towing.

brentm · October 21, 2009

I have a 2003 with 285/75/16 BF Goodrich ATs and get 11.5 mgp with no mods.

brentm · October 21, 2009

I get 9 mgp when I pull my dad's 28ft camper. Forgot to mention that.

Rat4go · October 21, 2009

If you went to BFG T/A tires in 285/75-16 from 245's and did NOT correct the speedo/odo, then it reads the mileage portion of the MPG about 7% low, which means your calculation of TRUE miles per gallon is also 7% low. Not that the extra ~.8 mpg that your calculation might be missing is huge, but.....

The BFG's do hurt a little compared to a highway tread, and from experience, going from BFG AT to G/Y MTR's in the same size is a tick worse. The real killer is 80 mph (which again, if you have larger tires and didn't correct the speedo is more like 85mph true speed). From somewhere in my youth, I vaguely remember that the wind load increases as a function of speed SQUARED. This says going 80 is more than 1.5x the wind load as going 65 and these trucks push a lot of wind at 65!!

MTPockets · October 21, 2009

This might sound crazy but I get around 17-18mpg (and yes that is calculated) in my CC, 6.0L

My truck is a 2009 with 3.73 gears and 6 speed tranny. Everything is stock and I try to keep it around 70 mph. Most of my driving is on the freeway though.

RJG183SA · October 21, 2009

This might sound crazy but I get around 17-18mpg (and yes that is calculated) in my CC, 6.0L
My truck is a 2009 with 3.73 gears and 6 speed tranny. Everything is stock and I try to keep it around 70 mph. Most of my driving is on the freeway though.

Those are some impressive numbers. I wonder what the 6 spd. w/ 4.10 gets?

What are your mpg around town, any idea?