35's didnt change my mpgs much, fixin to run 37s on a leveling kit.. scrubbbbb

 

Either Matt @ Gearheads or SCT directly told me that the new software updates will allow speedo corrections in 2005 and up trucks. 2004 and below are SOL.

These trucks are meant to pull, haul and guzzle. Mike and I have light weight trucks that weigh in at 7000lbs! Sure you can get better mileage with more efficient turbos and larger injectors with custom programs, but that is A LOT of chaff to lay on the table for a COUPLE of mpg points.

As I was told a few years ago, "It's easier if you don't fight it." Stay up on your maintenance and do not to buy into the BSers that are spinning yarns about their 20mpg all stock 6.0.

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Don't sell that truck! I took it in the shorts for 2 mpg when I bolted on 35s!

 

Your milage probably didn't go down very much if any at all if you can't adjust your speedo it just appears like a change in mpg. The heavier weight, especieally in rotating mass will affect fuel economy... but at least half of your drop is probably illusion because in reality you are traveling further per fill up than is reported on your odometer.

Keith

PS: Stock sizes available from tire rack are:

265/70/17 = 31.6" tall
275/70/18 = 33.2" tall
275/65/20 = 34.1" tall

 

Yeah, I wouldn't know anything about finding rates of change to calculate corrections speedo/MPG, then comparing those calculations with my GPS to double check my work. Nor would I know the NECESSITY to FILL TO UNTIL I CAN SEE THE FUEL to get the most ACCURATE numbers.

Yeah, the mpg drop was all in my head. Who knew that a taller tire would travel farther than a shorter tire would!?! That's some Star Trek technology there.

If you're thinking I found your post insulting, you're right.

BTW, you missed the 265/76-16 (31.5) tire size

 

Dude, I am in the process of going through my spreadsheet correcting my miles driven for each fill up so far based on the difference in size between the stock equipped tires on my truck and the ones that are currently on it.

You came into my thread with your "nobody fills a tank as good as me, so everybody else's mileage data is crap" attitude problem. I have to admit that I did reacted a bit to this, but not nearly as much as my first inclination because I am new here and didn't want to make waves with an established member. I bit my tongue and let it slide.

If you want to measure fuel with a dip stick down your filler neck, have at it. As long as your method is repeatable you get good data. I didn't call you insane, or say your methods don't work, or that you are full of crap. I didn't even think these things at the time. I thought "a bit quirky, but what ever floats his boat".

Your insistence that proper technique (same station, same pump, same method) gives incorrect results is bullshit. Even if the assertion that a fillup could be off by up to 6.5 gallons was correct, using the same technique every time would result in very close to the same amount of error every time. If I filled my 40 gallon tank on the 12th at purchase time of the vehicle, and only get 33.5 gallons into the tank, and I drive it for a month and fill it up using the same method, it will top off at 33.5 gallons again.

Any idiot can latch the handle and call it full when it clicks off. Neither one of us is doing this, but you refuse to believe that I am not just "latch and forget" filling.

I updated this thread to point out a mistake I had made, and share that others may have made the same error. My pointing out that I made a mistake somehow hit a nerve with you. Silly of me to think that if I can make a mistake, you could have made a similar error. I'm sorry that I offended your godlike wisdom while pointing out my own error. It won't happen again, I will assume you are perfect from now on.

My initial data was off to the tune of 1 mpg on a 12.625 gallon fill up because I thought I traveled 217 mile resulting in 17.15 mpg when in actuality I traveled 206.15 getting 16.33 mpg. If you in your twisted little way want to assume I actually burned 19.125 gallons over that 206.15 mile interval for a whopping 10.78 mpg then more power too you! Spread the word about my horrible milage.

Believe whatever you like,

Keith

PS: I didn't miss ****. If a 265/76/16 tire existed it would be 31.9" tall. No idea where you came up with those numbers. The 03 F-350 came with 265/75/16's (perhaps a typo on your part?) but that would still be a 31.65" tall tire. I said the stock sizes available from the tire rack. I didn't realize I had to specify "for my vehicle". Tire rack sells plenty of tires not stock to my vehicle, feel free to list them all and say that I "missed them".

 

"Lighten up, Francis".

If you don't like the answers that you are getting, most of which are coming from personal experience, then go ask someone else. That being said, you might want to ask how someone arrived at their conclusions before shooting your mouth off about their results being "imaginary". In other words, asking for advice then telling those same people that they are full of crap is plain rude.

 

I honestly was not trying to be rude. I almost called you Francis in my last post. My post about tire size milage changes wasn't meant as a "hey stupid, look at this" post... it was a "hey I did something stupid and missed this, did you miss it as well" at that point you went Francis on me.

I said part (probably half) of your fuel economy drop was illusion. You responded (nastily) that you had compensated for the illusory drop from odometer error... then imply that I said all of your milage drop was "in your head". Illusory and imaginary are two very different things. Tell me one thing, if you don't do the compensation for odometer error does the milage drop double from 2 mpg to 4 mpg?

I did go Francis on you in my response to that post. I dropped the fuel fill method issue after Mdub707's post on the subject and his suggestion that I look up the Harpoon mod. Did it occur to you that I took his advice and at least looked it up and am considering the implications? That is why I dropped the fill method subject. For some reason you brought up the fuel measurement issue (when the subject was tire size and odometer calibration) so I responded nastily in return on that subject. Perhaps a year from now I will be saying "man, I can't believe I used to not look down my filler neck, I was such a dumbass". You said you had to prove it to yourself. Does the guy who told you to look down the filler neck (was it Mdub707?) resent you not taking his word for it and having to prove it to yourself?

Emotocons are powerful. If I had put a smily face at the end of my post you may not have misunderstood it to be an attack and gotten so pissed off. If you hadn't used a bat wielding emotocon in your post I may not have gotten so pissed off myself.

Up until yesterday I figured you were a helpful guy trying to share information. I am not an "internet badass" sniping away from behind a keyboard and I don't think you are either. Can we chalk this up to a misunderstanding and move on?

Keith