Taking to shop for MPG issues; what to check?

[jblc]

#9 too much fuel in the oil?
Have you had an oil sample done? If so what % fuel?
If you have a leaky injector (s) then unburned fuel is getting into your oil. May not throw a code but worth having the dealer look at it. HP fuel pump could also be a culprit. But ONLY if your % of fuel in oil is high.

Ah, to clarify: too high of a level. Sorry for being unclear. I haven't checked the fuel % though. I just see the oil level continues to rise past the top dipstick hole, regardless of how much highway I drive (and despite really long trips).

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[jblc]

Continuing the reply list:

16)

because what your seeing isn't reasonable cause for a trip to the stealership.. or labeling it a lemon

I didn't give context for labeling it a lemon. I've had SO many issues with this vehicle, not just the mileage. It's constantly in the shop, and I'm only at 8k miles. If you search some of my posts you'll see some of the issues; these include a leaking cab, whistling sounds from the trim, weird body panel issues, etc. And there are still 3-4 issues I haven't had a chance to take it in for just due to time. I think it's totally a lemon

17)

19-20mpg on 100% highway running 65mph is terrible. Are you locking out the overdrive gears?

Nope, no lockout.

18)

It’s not the area loss. It’s the change in airflow. Can’t hurt to remove it for a recheck of mpg.

True. However, it was the same low mpg even before I put it in, and I didn't have it for 1.5 years.

19)

I would still like to see a picture of the truck with the topper

Yep, here it is Sorry for the delay -- I didn't have time to upload one before now.

 

[1pt21gw]

Ignore the Dash calculated algorithm, it is a guessing algorithm "based" on history, how you drive and what it thinks you will get. ~ it can be manipulated! Everyone here gets something different and we basically have the same truck.

Put your tire pressure or something else in the dash instead and watch that. Basically ignore the mpg. Hand calculate if you want to. Get good gasoline, it makes a difference!

Drive it spirited, vary your driving. Driving it the same way constantly is a downward spiral to low mpg. Freeway will get you better, just keep it under 2k rpm.

Doesn't matter what you do to it, lift, tires, etc. No mods or a bunch of mods, mileage loss is minimal. it's all about the motor and what it thinks it should do for you. Make it think and work for you. Try cruise control vs. feathering the gas pedal on a multi tank trip. - Spoiler cruise control is worse.

Just my .02 after 5 pages.

Nice lookin' truck btw.

 

[JesseS]

I have a 21 XLT w/fx4 package, leveled, tuned w/stock tires (I know) and a bed cover, and I get right at 20/17 (heavy foot) so you are about the same.

 

[myothercarizahearse]

@jblc what is the gear ratio of your rear end? I'm guessing you may have the 4x2 with tow ratio. my $.02

 

[jflogerzi]

@jblc what is the gear ratio of your rear end? I'm guessing you may have the 4x2 with tow ratio. my $.02

explain please. do tow package trucks get a different final drive?

 

[jblc]

@jblc what is the gear ratio of your rear end? I'm guessing you may have the 4x2 with tow ratio. my $.02

Great question -- I have no idea I do have the tow option as you mentioned, but I thought it only changed added tow hardware/software, and didn't affect drive-train:

Page 1 of this seems to indicate only one ratio: 3.73

Also, "This towing package adds a heavy-duty Class-IV trailer hitch receiver, and a 4/7-pin wiring harness to connect to your trailer's braking and lighting systems. "

 

[myothercarizahearse]

explain please. do tow package trucks get a different final drive?

not all, but there were 3 options and I can't remember the ratios

 

[myothercarizahearse]

Great question -- I have no idea I do have the tow option as you mentioned, but I thought it only changed added tow hardware/software, and didn't affect drive-train.

the ratio should be be on your window sticker

most have a 3.83 and other 2 options were 4.11 and 3.36 IIRC


edit: dislaimer- I'm going off memory. take info with lots of salt

 

[jblc]

the ratio should be be on your window sticker

most have a 3.83 and other 2 options were 4.11 and 3.36 IIRC

I see, good to know. I see "axle" and "73", so i'm guessing that means 3.73?

 

[Wytchdctr]

99% sure they all have 3.73

 

[Superdannyboy]

Stock I got 17 mpg mixed highway and city.

Now with my daily tune and mods I get 17 mpg if I'm only on highway going 70 which feels slow to me and 13 mpg if only city.

With my performance tune I get 10 mpg.

I tried driving steady at 60 mph on the highway when I would drive 100 miles a day to the university and boy I would literally start falling asleep idk how y'all do it I gotta hit 120 on the straightaways with no traffic.

 

[Superdannyboy]

99% sure they all have 3.73

Yea I agree. People have been wanting to switch the rear gear for years now. I think it became available recently.

 

[myothercarizahearse]

I see, good to know. I see "axle" and "73", so i'm guessing that means 3.73?

ya 3.73... had to google. it was 4 years ago when I saw it so

 

[CB750F]

Looks normal. When we first got ours it was doing 18mpg.
Talked to the service agent at first oil change(maybe 2nd?) and
they said too many variables but seems good.
Well, my wife was doing WOT all the time, she calmed down & now it's closer to 23 mpg in summer , still 18 mpg in winter.
Stock, driving 60mph, using cruise, 40/60 city/hwy, using 87
from top tier. It really sucks gas in the city & any head wind.

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