fuel mileage/big tires

i have an 00 7.3 350, it has 35/12.5/18 on it and a leveling kit. I am getting really crappy mileage. 460 miles to a tank on the highway =14mpg thats with a snowmobile in the bed. Towing a snowmobile trailer getting about 11mpg. I just bought the truck a few months ago low mileage and great shape, I dont know what it got with stock tires, is there anything I can do to improve this? I have an intake kit and 5" exhaust, also a chip. I just love the way the truck looks and really dont want to get rid of the tires and rins and go to stock it just wont be the same. Any way to get both of best worlds? how many mpgs are some of you getting with bigger tires? stock size for this truck are 265/75/16

you could do the aluminum alcoa's they'll save you weight and also go with a slightly smaller tire like say 33" tire and it'll still look awesome but wont hurt your fuel mileage as much. other than that get it custom tuned and tell the tuner you want a tow tune with fuel mileage in mind and a DD tune with fuel mileage in mind.

i have a set of factory steel wheels and a set of factory SD alcoa aluminum wheels and even though the alcoa's i have have no tire on them they're still night and day lighter than my factory steel wheels.

i got xd rims, i never really gave any thought to the rims, was more thinking of the bigger/wider tires hurting the fuel mileage. you sure the rim weight plays that much of a factor

everything that adds weight plays a factor in fact right now in my truck in my sig I'm in the process of replacing my injectors because theyre leaking and it hurts my fuel mileage but with my new lighter OBS factory alcoa's I'm still seeing about 23 mpg.

if you lighten your truck as a whole you'll notice a difference in her pep as well LOL.

Keep your foot outta it lol. My truck is a crew cab OBS with 35x20s and 300/200 injectors and I still get 17 if I stay out of it. If I get on the skinny peddle it gets ****ty real quick.

pullandpray said:

Keep your foot outta it lol. My truck is a crew cab OBS with 35x20s and 300/200 injectors and I still get 17 if I stay out of it. If I get on the skinny peddle it gets ****ty real quick.

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:whs: LOL

Read this thread:

http://powerstrokearmy.com/forums/showthread.php?t=17133

LOL ^^^

Was wondering if there was gonna be a link to it

going to read that link now, i swear no bullsh** i set the cruise at about 68 the entire way, only took it off on big hills and took them with speed goin into it and slowly letting off as it got to the top.

haha...I'm not expecting a 40mpg 350 truck and its only a sunday truck so i really dont care about the fuel $. more for bragging rights, and it feels good to drive 500 mile round trip with a couple gassers as passengers and not have to stop and fill up. But I known a lot of people over the years that get 20+ with a 7.3. I only witnesed 1 maybe the others were bull****tin. I also got gasser buddies that laugh at diesels and i been tellin them for years wait. till I get mine and you"ll see how good they are on fuel for a big truck. now after ten years i finally got one and its not what i expected.

Do you have the odometer and speedo calibrated for the larger tires?

SDS97_7.3 said:

Do you have the odometer and speedo calibrated for the larger tires?

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This. You're talking about roughly a 10% difference in tire size so unless you've recalibrated, your actual mileage is slightly better than the basic hand calculation- you've gone further than the odometer shows. My 7.3s are on 35-37s and my normal driving I commonly see 14-15 mpg uncorrected. Last time I checked it was 14.6 mixed driving, so if you add back the 10%, you're actually looking at 16 mpg. I can get more out of the truck when I restrict the right foot more, but mileage isn't that important to me. LOL

no they it has not been fixed yet. when im at 70mph on the dash im really doin about 73. i checked it with gps when i got it to see if it was correct. but thats a very good point that i never thought of. I can fix that through the computer with a programmer rigght?

Arisley said:

Read this thread:

http://powerstrokearmy.com/forums/showthread.php?t=17133

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Yes read this, and I'm sure you have 4:10's. Try driving slower on the highway.

yea bud so funny but your to late read a few posts ahead, and not complaing about mileage cause i want 4cyl mpg out of a big truck. but looks like the thread did produce an answer to my priblem. no i have 3:73 and like i said before cruise was set at around 68mph the entire way.
IMHO if your happy with 8-10 mpg theres something wrong with you unless its really got some mods thats understandable and if you notixe in the post evryone posts how much there getting if they really dont care cause "they own a big truck and it shouldnt matter what it gets cause its a big truck" then why did they bother to find out?
i dont mean to keep repaeating posts that people in the past have asked but couldnt find to many answers in the search tab so figured this is what the sites for,no?

aceltx said:

no they it has not been fixed yet. when im at 70mph on the dash im really doin about 73. i checked it with gps when i got it to see if it was correct. but thats a very good point that i never thought of. I can fix that through the computer with a programmer rigght?

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I think some have the ability to up to 35s. I still rock the 6pos, so I wouldn't know.

My dually with a lot of engine mods gets 16+ mixed. If I get on the freeway and keep it at 65MPH for a long distance, I will get 20. Now this is with keeping my foot out of it.

On a track, I will go through a 1/4 tank in three passes.

That's with 4:10 gears and stock wheels and tires. Four Alcoa and two steel.

wow thats good, im shooting for 20 i be very happy with that