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Actual, honest, real world MPG from your 6.5
- Thread starter 3500GMC
- Start date
kenmatt
Active Member
Not that any member here would pull my leg.
Let's see some numbers. Let us know your truck's config or weight.
kenmatt
Active Member
Stock x cab 6'bed 265-75-16 1500 18 mpg 80-85 mph 98 z71Not that any member here would pull my leg.
Let's see some numbers. Let us know your truck's config or weight.
kenmatt
Active Member
kenmatt
Active Member
2.69 gal. North of Boston mass.
KMarlow11
New Member
I need a little input from the experts so I came to the forums 
With the truck in my signature I'm averaging a little under 13 MPG. Everyone's saying that these diesels are getting up around 18 MPG easily but I certainly am not. Since I have a 6 Lug K2500 I have a ViN S engine so yes, I have all the emissions garbage. Still has stock intake, stock exhaust, and I have a heavy foot (turbo sounds nice). Just wondering what should be my first steps to improve on my MPG, and dont say take it easy on the throttle cuz we all know that wont happen
With the truck in my signature I'm averaging a little under 13 MPG. Everyone's saying that these diesels are getting up around 18 MPG easily but I certainly am not. Since I have a 6 Lug K2500 I have a ViN S engine so yes, I have all the emissions garbage. Still has stock intake, stock exhaust, and I have a heavy foot (turbo sounds nice). Just wondering what should be my first steps to improve on my MPG, and dont say take it easy on the throttle cuz we all know that wont happen
1994ch
Well-Known Member
Is that 13MPG town/city driving? If so that sounds about like mine, I get about 14 in town if I go easy on it and 13 if I listen to the turbo.........don't get 19-20 unless I am out on the interstate. Mine is a 94 K2500 with a steel flatbed on it so it weighs a bit more than stock.
Will L.
Well-Known Member
@KMarlow11
The emissions stuff hurts. The heath tune hurts mpg. turbo master hurts mpg.
There are some things that help both power and mpg. 4” exhaust, larger turbo with less back pressure, coating friction points throughout truck and heat coatings in engine, tuebo and exhaust, good injectors, keeping ect at 195f., timing being correct, wmi, and a few other things.
If you really want low fuel costs- get rid of the ds4 system, use a db2. Run wmo after heated centrifuged and cut with gas.
The emissions stuff hurts. The heath tune hurts mpg. turbo master hurts mpg.
There are some things that help both power and mpg. 4” exhaust, larger turbo with less back pressure, coating friction points throughout truck and heat coatings in engine, tuebo and exhaust, good injectors, keeping ect at 195f., timing being correct, wmi, and a few other things.
If you really want low fuel costs- get rid of the ds4 system, use a db2. Run wmo after heated centrifuged and cut with gas.
smokymtn65
Well-Known Member
Burb 13 around town 18 @ 55 , 14.5 @ 80 based on trip out west
Sid (6.2) K-10 4x4 14 around town 19 interstate
Dark Attitude 2 on a good day
Sid (6.2) K-10 4x4 14 around town 19 interstate
Dark Attitude 2 on a good day
Will L.
Well-Known Member
@smokymtn65 sometimes less is more (fun)!
My hummer got 10.5 ish without the turbo and 11.5 with it when I drove at same rate of acceleration and speed. That is gm6 and stock hummer exhaust. However it was more fun just driving faster so, back to the 10.5 range it went and with the fuel screw cranked in more than needed, she puffs a broken prius heart symbol if full throttle from a stop. I did turn down the screw for a couple tank fulls and raised it to 12 mpg, but that wasn’t as fun so it went back in.
That said I know from my other 6.5 pickups that I put better turbos on I can have more fun pedal and better mpg. Hopefully that all happens before it rolls out of my garage this time.
My hummer got 10.5 ish without the turbo and 11.5 with it when I drove at same rate of acceleration and speed. That is gm6 and stock hummer exhaust. However it was more fun just driving faster so, back to the 10.5 range it went and with the fuel screw cranked in more than needed, she puffs a broken prius heart symbol if full throttle from a stop. I did turn down the screw for a couple tank fulls and raised it to 12 mpg, but that wasn’t as fun so it went back in.
That said I know from my other 6.5 pickups that I put better turbos on I can have more fun pedal and better mpg. Hopefully that all happens before it rolls out of my garage this time.
MrMarty51
Well-Known Member
If I keep the speedo just below 65, adjusted to the over size tires would be about 67 or 68 mph, it will get 17 mpg which I think is pretty good for a K3500 crew crab.
jrsavoie
Recruit
On the 94 K3500 with NV4500, 4.10 gears, 4 door single rear wheel, I got 18 mpg before I added the ladder rack and side tool boxes. Then I got 16 mpg, Now I am getting 15 mpg.
Last edited:
MrMarty51
Well-Known Member
Cold temps also affects fuel mileage, causes mileage to decrease. I know when it gets into the 10s, My fuel mileage drops off very noticeably.
94 at Large
Recruit
I need a little input from the experts so I came to the forums
With the truck in my signature I'm averaging a little under 13 MPG. Everyone's saying that these diesels are getting up around 18 MPG easily but I certainly am not. Since I have a 6 Lug K2500 I have a ViN S engine so yes, I have all the emissions garbage. Still has stock intake, stock exhaust, and I have a heavy foot (turbo sounds nice). Just wondering what should be my first steps to improve on my MPG, and dont say take it easy on the throttle cuz we all know that wont happen
I have been around long enough to remember the national speed limit of 55. Best I ever got was 22 and I have the extended cab version. Usually average around 18 with my set-up. An "F" intake may help or opening up the plenum on the "S". Sorry couldn't be more helpful.
dbrannon79
I'm getting there!
Bringing this thread back to life, hope no one minds! it looks like the average mpg's are around 13-18 for everyone. my truck I have always gotten 13ish from the get go. running 4.10's with 265-75-16 oversize all-terrain tires and my speedo is accurate. each fill up I add about 8 oz of power service additive, always wondered if 2 cycle was better or worse.
Back when I had bought the truck, it had 235's and the speedo was almost 5 off. Whats the general consensus on tire pressures? with the all-terrains I have are rated for 80 max, I have had them at 50 since I had them installed. I'm wondering if I would see any improvements if they were at a higher pressure, maybe ad 65-70psi. though I think I would feel every bump in the road then.
Back when I had bought the truck, it had 235's and the speedo was almost 5 off. Whats the general consensus on tire pressures? with the all-terrains I have are rated for 80 max, I have had them at 50 since I had them installed. I'm wondering if I would see any improvements if they were at a higher pressure, maybe ad 65-70psi. though I think I would feel every bump in the road then.
MrMarty51
Well-Known Member
Still getting 18 over here. Of course though, these cold temps always knocks the 
out of fuel mileage but I have not had to run the beast too much since it did get cold.
out of fuel mileage but I have not had to run the beast too much since it did get cold.
Will L.
Well-Known Member
On your tire pressure, you should do a chalk test and set pressure according to wear.
A proper rolling tire is going to perform better, give longest life and give best mpg.
A proper rolling tire is going to perform better, give longest life and give best mpg.
ak diesel driver
6.5 driver
Basically put chalk across the width of your tire and drive until you can see where it wears off first. If it wears off the middle then it's too high, shoulders first too low
dbrannon79
I'm getting there!
I have never heard of the chalk test until now! I'm gonna have to try this. I mainly run my tires at lower pressure so it's not so rough! which is prob my down fall.