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Fuel mileage on 285s

tyhuck

By tyhuck
in Tires, Wheels & TPMS

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Black2011 Enthusiast

Black2011

Posted
Posted

2011 4.8 4 speed, 4x4 on 265's got 16.7mpg highway.

 

with 285's got 13.5

 

I feel with taller gears this truck would do much better on fuel.

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tyhuck Senior Enthusiast

tyhuck

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Well, Im gonna have a slight change on the ooriginal question. i have recently changed trucks to a crew cab with 4.10s. Im not sure of the previous owners mechanical maintenance procedures, but I know they at least did the regular oil changes. Im concerned with the mileage I am seeing. The first tank out of my new truck was only 14mpg. I was getting that with 3.42 gears and 35s. I would have thought that lower gears and smaller tires would have netted more MPG, or ate least closer to 16 or so.

 

What are some of you guys on 285s with 4.10s getting for MPG?

Black2011 Enthusiast

Black2011

Posted
Posted

4.10's are really tall for 265's. you could easily run 285s or even 295's with that gearing and expect an increase in milage, due to the lower rpm.

Big Whiskey Senior Enthusiast

Big Whiskey

Posted
Posted

I'd run a couple more tanks through it, to get a more accurate average. It should be much better than your old truck.....unless your enjoying the extra giddy-up of the new 4:10's a little too much. :P

tyhuck Senior Enthusiast

tyhuck

Posted
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Posted

Im gonna run some fuel system cleaner through it as well and see if that helps any.

Big Whiskey Senior Enthusiast

Big Whiskey

Posted
Posted

Im gonna run some fuel system cleaner through it as well and see if that helps any.

 

Yeah, that couldn't hurt anything. Could also check your air filter too.

tyhuck Senior Enthusiast

tyhuck

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The air filter is actually the Air-aid from my 05, so I know its pretty clean.

 

Its only got 69K on it, but I was also thinking of doing a Seafoam treatment on it, just to see how much crap comes out. They had the oil changed at some quickie place, so who knows what kind of oil they put in it, and what kind of sludge is in there. Im wondering if maybe the oil level sensor has some sludge on it, and that's whats causing the "Check oil level" message Im getting.

tyhuck Senior Enthusiast

tyhuck

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Well, I put a can of Seafoam in the tank and ran it till it was about 1/4 full. Filled it up and calculated my mileage. Only got 13mpg out of this one. Then I realized that Im not calibrated for the 285s yeat, so I got home and figured out what the difference was, and refigured, but only got 13.4 out of it.

 

Would mostly highway driving at 70 cause this low of mpg out of a 5.3? If I would have known that I would get this bad of mileage out of it, I would have gotten a 2500HD and at lest had the 6.0 and the 4L80E.

 

ON a separate note, I also found out that both my hub bearings are bad. GRRRRRRR!!!!

TimmyG Senior Enthusiast

TimmyG

Posted
Posted

My 11ccsb 5.3 avg 17 mpg

 

Sent from my SCH-I535 using Tapatalk 2

 

Run the sea foam in your oil to right before your next oil change

 

Sent from my SCH-I535 using Tapatalk 2

TooTall1 Enthusiast

TooTall1

Posted
Posted

My 2008 extended cab 5.3l with 3.73's, 4wd is averaging 20mpg right now. The DIC says it's getting 21, but figuring it out at the pump it's closer to 20. Most of my driving is 55-60 mph with cruise on, rolling terrain. I'm planning on going to 285's soon and getting a tune. Hopefully the numbers won't change much.

tyhuck Senior Enthusiast

tyhuck

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My 11ccsb 5.3 avg 17 mpg

 

Sent from my SCH-I535 using Tapatalk 2

 

Run the sea foam in your oil to right before your next oil change

 

Sent from my SCH-I535 using Tapatalk 2

 

 

I am. Probably gonna do an aerosol treatment of the top end too.

 

Would it be bad to run the seafoam in the oil for up to 500 miles? Ive never run it over 100 miles before. Whats the max you want to leave it in there?

TimmyG Senior Enthusiast

TimmyG

Posted
Posted

I have never been past 60 miles on seafoam

 

Sent from my SCH-I535 using Tapatalk 2

Mckenzie Senior Enthusiast

Mckenzie

Posted
Posted

Well, I put a can of Seafoam in the tank and ran it till it was about 1/4 full. Filled it up and calculated my mileage. Only got 13mpg out of this one. Then I realized that Im not calibrated for the 285s yeat, so I got home and figured out what the difference was, and refigured, but only got 13.4 out of it.

 

Would mostly highway driving at 70 cause this low of mpg out of a 5.3? If I would have known that I would get this bad of mileage out of it, I would have gotten a 2500HD and at lest had the 6.0 and the 4L80E.

 

ON a separate note, I also found out that both my hub bearings are bad. GRRRRRRR!!!!

Thats about right, you should have been able to get mabe a little bit better than that...Did you have cruise control on and did you encounter any steep hills?

 

I can pull 14.5 mpg if take it easy on the interstate

tyhuck Senior Enthusiast

tyhuck

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No cruise control and on rolling terrain. I don't hold to the 70 going uphill. I just kinda let it cruise where it feels comfortable. She will drop to 65, but it doesn't downshift.

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