So I have never payed much attentions to lifts or big tires cause I have been more concerned if my truck will make it to its destination. But finally it looks like I can start to think about such things. I know I am going to get a little lift from my Dana 60 SAS and I am excited for that. But as we talk about things like final ratio ( https://www.ford-trucks.com/forums/1...verdrives.html & https://www.ford-trucks.com/forums/1...-crew-cab.html ) tire size is starting to cross my mind. I do like the looks of big tires, but what kind of pros/cons are associated?

• Wider tires have more drag, therefore lower MPGs, but how much?
• I have a dually so how big can I go with out rubbing?
• Will a taller really tire give me better mileage?
• What about tread? How much of a factor is this?

Ultimately what I am looking for is a way to make a decision so I can start plugging in number to figure my drive train setup and what kind of final drive ratio I can attain.

Cheers,
Devin

 

okay i can answer this because i've made the swap from stock to 35' s ..

the extra width penalty is more then offset by the 'gear reduction' effect of longer runout ..

it's the same effect as a 'baby' overdrive ..

before when i was running stock with 3.55 my truck beat my brains in on the highway and it was just uncomfortable to drive fast ..

now i can keep up 75mph very comfortably and now gear overdrive looks somewhat like a luxury as compared to a necessity ..

this is alot of weight to have riding on the pizza cutter wheels .. the driving manners are a whole lot more comfortable with meat .. especially because the front steering is notoriously sloppy with the extra bushings up there .. the meat will keep this better planted ..

i noticed a good 10% - 15% milage improvement .. and 20% 'feel' improvement .. 75% highway speed improvement ..

some of my gains can probably be attributed to better tires themselves not only size ... i am running bfg ko's .. notorious and best selling all terrain tires for a generation for a reason ..

they are the best .. they offer really good .. long tread wear .. awhole lot of miles before they wear out .. they're quiet on road .. and perform really well off road .. of course .. and get outstanding milage for an off road tire ..

that said they aren't everything .. nothing can do it all .. in 2 areas they are lacking .. the sidewalls somewhat bulge a big wider then the tread .. so if you're off roading in a place like we have here with a small topsoil layer inhabited by many many sharp rocks .. well .. you can have sidewall punctures if you roll over a rock just the wrong way .. i have torn a few like this ..

second drawback is they aren't great in the snow .. or extreme rainy sleet weather .. if i had a 2wheel drive in an area that saw 4 mos of snow this would be a knock off these tires ..

though i must admit i see the slight 'slippyness' when on road in extreme weather as bonus because it just enables me to drive in 4 high without fear of binding ..

in snow or extreme rain i just run in 4 high and it plants perfect ..

on those days when everyone else stays at home .. i go in 4 high with the lockers in the worst conditions just fine and it grips great ..

also bfg came out with a new tire BFG KO2 .. i haven't rode these yet .. but they claim to have remedied the 2 drawbacks to the KO's .. they have an ultra wide shoulder to prevent sidewall punctures .. and are supposed to handle snow better ..

i will stick with KO's because i like em' and not much frigid snowy weather here .. but i do like that the tread extends further and protects that sidewall ..

if money were no object i would take a look at that new KO'2 and definitely i can recommend the big wide KO's

 

Im assuming non OD trans, so yes tall tires will help mileage, even being wider, but the wider you go the less mileage you will see due to drag and weight. Being dually, to even run 235/85 i think you will have to space. In your shoes, i would space just enough to run 255/85s. Theyre the "narrow" profile, but dont look like pizza cutters the way 215s and 235s do. Unfortunately, theyre the tallest tire they make in the 85 ratio at approx 33.5". That should give you a 2.5-3" gain over stock.

 

Yeah I think I am sold on 315 75 16 's. There are some sweet pics out there if you search the keyword "f350 dually 315 75 16"

 

Granted some of those weren't dually or 16" rims but they do look flippin sweet.

Devin

 

Oh and I realized I am only running at 215 85 16 so even smaller than what my door tag said.

Devin

 

wow yea .. i never see dually's with fat tires ..

and i must admit ... they do look gnarly .. freekin sweet ....

so .. ?? is 2 big fat tires up front and 4 regular width tall tires a possibility ..

i bet that would be a killer combo .. though would throw off the rotation scheme

it would look good ... and probably drive very nice

 

just one more thing to add >>>>

 

Im not a fan of big tires on a dually.... whats the point? Id say those last couple arent 315s, in fact the crewcab looks to be 255/85s

 

Check out these 325s

http://www.powerstrokenation.com/forums/19-1994-1997-general-aftermarket/112165-lets-see-those-obs-crew-cab-pics-19.html#post1706336

 

Yeah I've been ruined now, I tried to look at the 255 85s but those 315s though.

I bet I would be slipping all over the place in those, but people say they tend to get good snow traction. That is BFG K02 I mean ( http://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=All-Terrain+T%2FA+KO2&partnum=175R6KO2RWL&vehicleSearc h=false&fromCompare1=yes )

But I wonder with a sander in the back if that would make enough weight to make good traction.

Devin

 

I'm easily amused! Found these beauties on the internet when searching for "divorced bw1356" under images. 79 stepside build - rocks,ags,diesel - Pirate4x4.Com : 4x4 and Off-Road Forum

Devin

 

I run 37X12.50X17 BFG KM2s, the quality, mileage and ride are excellent. I've owned several sets of KOs and KMs and have always been very happy with them.

I inherited a set of 36X12.50X16 Super Swamper TSLs with my most recent truck purchase. They are great if you spend most off your time off road. They are a rough ride on the hard top! They are currently mounted on a set of Mickey Thompson classic 2 wheels..8X6.5 bolt pattern if anyone is interested..PM me!

 

Post some pics!

Devin

 

yea i ben looking for some dead tractor tires ..

for free or next to free ..

just to fill them with water ..

and weld them to an old F100 as a yard ornament

dude moster truck // //