so i have recentley got new tires (285) and i went bigger then i had and some thoughts came to my head for them.

1 do they affect the way it reads mileage?

2 do over sized tires hurt the transmission/rear end if u dont get it tuned?

3 do they reduce the power of the truck or not?

4 should u get the pcm/ ecm reprogrammed for oversized so everything runs smother or does it not matter?

 

1. No
2. Yes any over size tire hurts the trans, but a 33 if your trans is ok then i wouldnt worry just keep an eye on it and do some tune ups.
3. 285s not so much power loss not enough were you can notice it.
4. I would say no but im sure other can anwser that better

 

1.) Yes, you're odometer is reading slower than you are actually driving.
2.) Depending onring and pinion gears, but 33s will be okay on 3.55s. 4.10 gears would be preffered but i wouldn't do the swap unless you plan to go bigger, and if you planto go bigger go to 4.56 or4.88 gears
3.)Yes if you don't compensate by getting lower gears
4.) If it's a 98 or newer I beleive you can use a programmer to reset your speedometer and odometer to account for the bigger tires. It won't make it run any smoother it'll just correct your speedometer.

 

1. I just put 285 on my truck and at 60mph im actually doing 65 so its about 5mph off wich isnt any thing to worrie about.
2. with 33s there shouldnt be any problems with the tranny
3. Yes Iv notice that is not to bad till I hite 5th and then I have no power.
4. Like he said my friend has a program and its a 01 and all he did was correct the speedo and other than that you cant realy do a whole lot.

 

1 do they affect the way it reads mileage?
yes. odometer under-records mileage. speedometer under-reports speed.

2 do over sized tires hurt the transmission/rear end if u dont get it tuned?
no.
i've never heard of 'tuning'.

3 do they reduce the power of the truck or not?
with stock 3.55 gears, your "get up and go" will suck.
you will likely want to always turn overdrive OFF for city driving under 55mph.
with OD off, your rpm will stay up around 1800-2200 which gives you an acceptable feel.
with OD on, your rpm will drop down to 1000-1300 which feels like a pig.

4 should u get the pcm/ ecm reprogrammed for oversized so everything runs smother or does it not matter?
it doesn't run smoother with/without pcm change.
its a good idea to correct your speedo and odo so you don't get speeding tickets.
you can do this with a programmer, or visit your stealer and pay them $30-60 to do it,
you'll have to pay this each trip, and they may/may not understand what you want,
also, they may tell you they only have a computer choice for 245/75 or 265/75,
and not know they need to choose "other" and put in revs per mile.
i don't think it hurts anything to run uncorrected, so it really doesn't matter, just personal choice.

 

I put some 4x4 tires from a 2000 chevy on my truck,
it did change the speed (gotten a few more tickets)
i did have to have the pumpkin changed

 

well thankx, i think tho my 360 should be able to handel it tho, but so the trans will be ok then, i have nothing to worry about, but i prob just get my odomiter corrected then, i will have to see if when i get on it how it feels i havent been able to do it with all the snow here. But for tires i got cooper discover s/t and i like them so far, what do u guys think of them?

 

i've got some cooper discovery all terrain. they look good. good on the highway. not too noisy. but they suck in the mud.

 

You should have got the STTs they seem alot more agressive. I was looking at a set before I bought mine.

 

yeah i like them so far, i think tho the stt is a directinal tire and they are more cash too, i see them on more diesels tho