Hey guys, I'm just curious if any of you can think of anything else I can do to gain a few mpg. Yes, I know it's a truck with a 4" lift and 35's so I can't expect 25 mpg but even while running SRL in addition with all mods in my sig, the best hand calculated mileage I can get is 13. I use premium diesel and additives every other tank and the lift and tires are here to stay so what else can I do? Thanks!

 

I'm sure you know what is causing your miserable mileage so I won't go there...

However a couple of things I've done that have slightly improved my mileage include:

- running tires at or near max inflation pressure
- using synthetic engine oil (Shell Rotella T6 for me)
- installing a tonneau cover
- not driving like I stole it...

Good luck!

 

With all your givens that you want to keep, Your right foot will be the #1 mileage tool in your toolbox. slow starts, consistent speeds, more highway, s-l-o-w-e-r on the highway (you are pushing a lifted brick with wide tires through the wind) - if you could keep it in the 60-65 range that would help a lot, slower maybe even better.

Not a lot of magic here. I'm planning on dropping back to stock size tires for two reasons: I'm running at the max weight and the BFGs are looking like they will delaminate like the last set did and #2 It is quicker and better mileage w/o power robbing tires on it...

I guess a: YMMV would be appropriate here...

 

Small tires aren't sexy.... until you're towing

Going from 35s to 31.5 is almost the same as going from 3.73s to 4.30s. The math isn't exact, but that's the rough equivalent.

Gears likely won't help your MPGs much, but if you went to 4.10s or 4.30s it would pull better. Lot of money though, so it would only benefit a full-time puller who wants larger tires.

 

The three best things that bring up my mileage are Gearhead's 8K tune (better mileage than SRL for me, but I haven't had a chance to give it a fair test ), Rotella T6, and Optilube.

 

Is your speedometer adjusted for the larger tires? If not you are getting better mileage than you think you are.

 

Thanks for the replies! No, my speedometer hasn't been adjusted for the tires so I guess that would be a little improvement. As for tires, I've got a friend with an 07 with a 6" lift 36' tires and 3.73 gears and he can get up to 18 mpg on a good day with looney tune so that's why I figured my mileage was a little low. I will admit that my right foot definitely played a role in my last fillup which calculated 12.3 mpg. Is there any fuel problem that could cause the mileage loss?

 

There are too many variables to get a correct answer for what your asking.

When I owned my '04 6.ohL PSD 4dr ShortBed 4wd 16inch rims LT265/75r16, it would get 16 to 17 mpg @ 60mph, the truck was completely stock.

Now with my '06 6ohL PSD I am only getting 13 mpg and thats @ 65mph. But with my '06 its a 4dr LongBed 4wd with 17 inch rims 35 inch tires and a leveling kit.

There is no simple fix, and usually we dont like to hear the answers that are provided, because were 6.oh owners and we like to put our foot into the right pedal.

Good luck with keeping your foot outta the fun pedal!

 

I gained 3 mpg city through two tanks with 4 new injectors. Had two on the passenger side acting up. Fuel saving will pay for the parts and labor in the next 8 months. I'm now running 16.2 around town and 18.5 on extended highway driving at 65-70.

 

Shed all the extra weight that you can.
Don't run a full tank. Fuel = weight
Did you dump the spare tire and tools?
Do you have a large hitch hanging off the back end?

I think you get the idea.

How many miles on the air filter?

Sean

 

And dont forget that rotational weight loss is the best thing you can do. Smaller tires, aftermarket light rims, etc. But either way at the end of the day, its still a 8-9K lb brick that were trying to move here.

 

Ok, I will try to drive as if I am afraid of the 2k tach mark this tank and see about ditching any of my excess junk weight and see what it does to the mileage this tank. Not sure on the air filter, but my MAF readings are good and the air filter minder doesn't show any problems. ^^ I was thinking that injectors might be a contribution- the truck does have 130k on it. Is it necessary to get remans, or would having my current injectors rebuilt do the same thing? I especially noticed that my injectors have stiction problems after losing the precycle with the atlas 40 FICM tune even with T6 and archoil.

 

On the injectors I think your going to see better with the remans vs
the home-brew ones. They will be able to test and correct problems
that you won't be able to.

On the 2K tack mark. It is more how you get to the speed then
what it is IMHO. I find that running at 75MPH on the freeway and
not having to stop and start gives me the best MPG. It's that stop and
start that kills MPGs.

I really don't think that the air minder is that accurate and tends to
be on the slow side when it comes to letting you know that the filter
is getting dirty. One thing I will do when I change this one I have is
place my dual manometer on it to see just how much restriction it
is giving to the airflow. I will do one before and one after the change
of filters.

The last thing about excess weight. That will show up on the long
haul with tracking. So one tank after dropping a few hundred pounds
will take time to show up. Things like tire and rim add a lot and if you
can't use it and the tools to install why pack them around. The funny one
is the guy that still has the 4 80 LB sand bags in the bed and it's July.



Sean

 

The 4" lift isn't helping your mpg, nor are the larger tires. If you want to get a better handle on your actual fuel economy use a GPS to record the number of miles driven. Mine shows 111 miles on the GPS vs 100 on the odometer, and is consistently 5 mph faster than what the speedometer shows. Your 12.3 mpg doesn't actually sound too bad considering your modifications, driving style, and you haven't compensated for the odometer being off.

 

^I'm glad you brought up the spare because I have been meaning to ask about it- would it even be safe to run the factory 32" spare with having 35's? Also, now that you mention it weight in the bed, I do have a 450lb headache rack back there that probably doesn't help! Again on the injectors, I was meant having my current ones rebuilt by a company such as warren or holders etc...That still wouldn't be the same as a reman? Thanks!