Fuel Mileage Question

Timebomb

Timebomb

Bootney Lee Fonsworth
Joined
Apr 17, 2007
Messages
2,069
Just wondering what some of you guys are getting for mileage on a 160hp 4x4 Ex cab Auto 3.55 gear ? I have filled up 2 times over a 500+ mile tank and have gotten 14.8 and 15.3 unloaded and 80% highway also just topped it off last night after 127 miles and it came out to 14.5. Seems low to me. I run Stanadyne performance addative as well. Truck has a K&N drop in filter and a 4in exhaust with straight through muffler. Thats it 100% stock other then that with 111k on the truck. Has a new lift pump and filter runs great with no smoke or other issues. No brakes dragging either and tires are 305 pro comp AT's, any thoughts ???
 
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To start with, with the 305 tires, your odometer is off by 7.5%. That means your 127 miles reported by your odometer was actually 136.5 miles, 127 X 1.075=136.5. Easier way to figure it would be to just multiply your MPG calcualations by 1.075, 14.5 X 1.075=15.6 MPG.

The larger tires probably cut your mileage a little, depending on where you are you're probably running a winter blend which cuts your mileage, the auto will not be as efficient as a manual, and depending on what you're calling "highway" that may be effecting it.

Did you fill up with the same pump to the same level? With only @ 135 miles, a slight difference in the amount of fuel you put in will make a huge MPG didfference. Your 127 miles/8.76 gallons=14.5 turns into 15.4MPG if you only put in 1/2 gallon less and 13.73 if you put in 1/2 gallon more. I average my mileage over several tanks, say 2200 miles/111 gallons=20MPG.

My '95 RWD auto, 3.55 LS, gets it's best mileage, 22-24MPG, running a steady 45-50mph. At 70-75mph it drops to 19-20MPG.
 
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Thanks for the info, I used the same fuel pump at the same station and temp was withing 5 deg F at the same time of day. Also I filled it up to the rim of the filler nieck each time, shaking the truck to get the air bubbles out. Takes a wile to do that but no one is ever waiting to use the pump so I do it.

2 weeks ago I was able to get 536 miles out of a tank, Think I put in around 36-37 gallon, I ran it out of fuel (Not intentionally)and was able to drift it into the station...lol I should have purchased a lotto ticket wile I was there.

What about running OD, should that be done only on highway or a given mph ?
 
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Try Power Service. It also makes a difference where you get fuel. Sheetz and AC&T give me the best mileage.
 
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LReiff said:
Try Power Service. It also makes a difference where you get fuel. Sheetz and AC&T give me the best mileage.
Click to expand...

:Throwup:

I do agree with Lee about where to fuel, but I recommend against Sheetz - at least in my experience and friends' experiences (some unfortunate).

I like PS or some two-stroke oil, but I don't think that will do more than 1-2 mpg. How fast are you running on the highway?
 
I got about 17-18mpg at 70mph with mine when it was stock. Tires make a big difference. The 7.3L PowerStroke we had a while back for the mag on 44's only got 9.5mpg.
 
I know that my fuel economy has gone to crap since the first of the feb as well as a few others ive spoken to. I went from 17-19 highway to 14-15 high way
 
yep I think they've screwed up the fuel or something. I used to get 19.5 all the time, now I get 17 at best.
 
If i drive half highway half city I get around 19-21mpg depends on how i feel like driving too, When I am on a tuning spree I get around 450 to tank with heavy pedal driving. but
I went over 600 miles driving half and half highway and street shifting before 2k rpms
 
I got 10mpg city, 14mpg highway.. or there-abouts. In my case I know something is screwed up. Judging by the feedback I get, Im supposed to see about 14/18 with what I got.
4wd, auto trans, auto with high stall converter, 4.10 gearing, smaller tires that put you out of that 1800rpm sweet spot cruising on the highway.. all that stuff sucks up fuel to some degree.
And yeah, thank the EPA for this crap ULSD stuff. We get to pay more for less.
 
Yeah something is up. I just found a recipte from 6/11/11 and I drove 633.8 Miles and added 31.576 gallons of fuel so thats 20.1 mpg. That was with 265 all season Michelines. No way adding a 285 A/T would kill it that much. Also that was with no additive back then. I certanly dont put it past out government to add crap to the fuel so we have to buy more. But I could be wrong and it just be winter blend still.... doubt it
 
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